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Preface

Red Country, Blue Country. I am both red and blue. I was born in a farmhouse in Charter Oak township, , and I grew up in nearby Denison, Iowa. Denison is the county seat of Crawford County and contains most of the population of the county. In the 2016 Presidential election Crawford County went 67 percent for . The omnipresent political maps show our region as dark red country. I was educated at the , in Iowa City, which is a university town, and of course liberal. I do not need to look up election statistics to know that it is dark blue on political maps. I love both Denison and Iowa City. I cannot think of better places to grow up and go to school. I wish that young people today were as lucky as I was. The problem is not the place or the people. Red country people are good people. Blue country people are good people. Let me give liberals a little reassurance about Denison, given its landslide vote for Trump: in 2008 Obama handily won the Presidential vote in Crawford County. On election night, as results began to show an Obama victory, I had tears in my eyes. I was proud of our country. When Obama took office he had a lot of good will, even in red country. Yet Obama failed badly. Sure, he did some good things, and we enjoyed an exemplary First Family. But Obama did not convert opportunities to improve fundamental prospects for youth, who secured his election. He did not deal with energy and climate effectively, even though the required actions also would have addressed major economic and national security issues. Obama lost Crawford County in the 2012 election. The public recognized that he had done little to fix the Washington swamp. Special interests still ruled. Obama was becoming an elitist.

I tried several times to affect government policy on climate, but failed. The most recent time was near the end of the Obama administration. I was a plaintiff, as ‘guardian of future generations,’ in a lawsuit against the U.S government brought by Our Children’s Trust. We were asking the Court to require the government to have a plan to reduce fossil fuel emissions at a rate that would bring atmospheric CO2 back to a level required to stabilize climate. Late in his administration, Obama accepted the idea that the U.S. needed to reduce its emissions by 80 percent by midcentury. That was almost the rate that we were suing for! So why not agree to a plan to slash emissions and settle the lawsuit? This would enable later Presidents to merely continue or perhaps even accelerate rational phase-out of emissions. Government actions that violated the settlement could be challenged in court. At the very least, it would deter any later President from expanding fossil fuel use. I learned that a plaintiff is allowed to discuss a case with the defendant. As I have indicated, in conjunction with a number of young people I helped launch a lawsuit in 2015 against the U.S. government for causing dangerous climate change. So late in 2016 I tried to contact high level Obama Administration officials, but I found it more difficult to establish communications than it had been in the G.W. Bush or Clinton Administrations. Eventually a former high-level Obama official agreed to serve as a go-between, and through that person we tried to persuade Obama to accept a settlement.

1 © 2020 James Edward Hansen. All Rights Reserved. However, each interaction was frustrating. The focus of the Administration was on preserving Obama’s Clean Power Plan to limit coal use at power plants. What a trivial contribution. Coal use was already being phased down, because gas was cheaper, and clean power rules could just be reversed by a later President. A settlement of our lawsuit made so much sense, but we ran out of time. I concluded that much of the problem was my slowness. Coincidentally, my wife Anniek mentioned a discussion she had long ago with my sisters – about my inherent slowness!

“Has James always been slow?” My sisters were taken aback by the question. They were already surprised that I came home, to Denison, Iowa, with a beautiful young European woman. It was the first time they had seen me with a girl-friend. I even talked to her. I was 29 years old. (I learned of this conversation only recently. Anniek’s question was not one she would have asked on first acquaintance, so it likely was on a later trip to Iowa.) My sisters’ first reaction was denial that I was slow, but then something like “Well, he was slower after his appendix burst.” That explanation – that a 3-year old’s burst appendix could cause slowness decades later – was implausible, but it forced me to think: my sisters had probably used that excuse on their little brother’s behalf a number of times. This also set me thinking more about the slowness and missed opportunity business. Upon reflection I had to admit that such occurrences stretched all the way back to when I was a kid!

My journey was not a ‘hero’s journey.’ On the contrary, I lived a life largely of indulgence in various ways, but especially in what Richard Feynman describes as “the pleasure of finding things out.” I took advantage of Anniek’s love, support and dedication to our family, as she handled most of the parenting and home-building. In 2004, when near retirement age, I ‘temporarily’ reduced my government work time to 40 hours per week, spending at least as much time to prepare a talk to criticize the government for its failure to address climate change. I also argued that the Intergovernmental Panel on Climate Change (IPCC) was understating the threat posed by global warming of a few degrees. My talk was ineffective. A year later I gave another talk of the same ilk. This second one drew the ire of the government, and their resulting efforts at censorship brought publicity. Students and environmentalists then cajoled me into trips where I encountered the most egregious fossil fuel activities, such as mountaintop removal coal mining and tar sands extraction. I tried to help draw attention to the foolishness of pursuing these dirtiest and most carbon- intensive fossil fuels. In mid-2007 I began recording my Communications about these topics on a webpage (www.columbia.edu/~jeh1), but these had no effect where it mattered, on the governments of the United States and other nations. Then, during the transition from the Obama to Trump administrations, I read the letter I had written to Obama in December 2008 during the prior transition. Nothing had changed! The policy advice in the letter remained valid, but unacted upon. I had tried but failed to get an audience with Obama. There would be even less chance with the incoming (Trump) Administration.

2 © 2020 James Edward Hansen. All Rights Reserved. I was 75 years old, and not making progress. So the best thing I could do was write down what I had learned, for the sake of younger people: I resolved to write the long-delayed Sophie’s Planet. Again I was slow, but I will try to get the book out before the next election.

Can scientific objectivity help us find a solution to our energy and climate problem? We will see, but my working assumption is that not only can it help, but that it is essential if we are to achieve the actions that are needed. I will explain the scientific method later by describing how I learned it, but let me emphasize here one crucial aspect that is difficult even for many scientists. You cannot let your preference, your ideology, affect your assessment of a problem. In part for that reason, I am a political Independent. If you are a Democrat or a Republican, a Liberal or a Conservative, I hope that I can get you to question your own party’s positions, as well as the other party’s. We need to draw back from unproductive extreme partisanship. Now I write Sophie’s Planet for young people, especially to those people who will provide leadership as the world digs its way out of a difficult situation. I point out some of my mistakes, in those cases where it might conceivably help a young person.

Sophie’s Planet is the world that today’s young people, their children, grandchildren and the ‘seventh generation,’ will inhabit. If we take care, Sophie’s Planet will continue to be a spectacular planet, a world in which humans co-exist with and appreciate all life on Earth. Yes, I understand that climate change is a real threat. Extreme climate events – floods, storms, heat waves, fires – are becoming more extreme, low latitudes are becoming uncomfortably warm, sea level is rising and may eventually threaten coastal cities. If we let these effects continue to grow, emigration pressures might make the planet almost ungovernable. It is also true that there is, as yet, little effective political action to stop climate change. Indeed, much reaction that is occurring is at the extremes of the political spectrum and is unhelpful. On one extreme, we see near-panic over the imminence of disastrous global effects. Young people, already living in a fast-paced stressful world, cannot avoid this din. The nurturing environment that children need in their formative years is impaired. Negative consequences for the mental health and well-being of our youth are growing. On the opposite extreme, we see denial of human-caused climate change. This extreme is driven by fear that liberals will use climate change as a basis for increased regulations and taxes.

This is no time to despair or to panic. The average worldwide standard of living has never been higher. We have developed knowledge and the potential for technologic advances that are capable of dealing with climate change and preserving our remarkable planet. Time is short, though. We must avoid passing the most dangerous point of no return, the point at which it becomes impossible to avoid rapid sea level rise of many meters, which would spell the demise of almost all coastal cities. To avoid such calamity, to restore a beneficial climate, we must understand the big picture: the climate system, the energy system, and the political system. The fossil fuel industry dominates our energy system and is now driving both our climate and political systems. However, there is no good reason why we cannot regain control of our future 3 © 2020 James Edward Hansen. All Rights Reserved. from the fossil fuel industry. It will take work – lots of hard work – but that has always been so, especially in a democracy.

I do not ignore the difficulties posed by growing political polarization and wealth disparities. These problems have grown large in recent years and are occurring almost worldwide. The wealthy are using political systems to protect their privileged positions. The public is frustrated because government failure is obvious. People understand that our political parties have become elitist. Politicians take money from special interests and they want to maintain their elite status. The system is inevitably corrupt when politicians are allowed to take money from special interests. Political corruption has been with us since time immemorial. The problems can be fixed. What is different now with respect to global climate change is the fact that one of the largest industries in the world, the fossil fuel industry, is intimately involved in creating the physical problem and corrupting our politics to thwart its resolution.

Fossil fuels are not evil. One gallon of gasoline contains the work equivalent of 400 hours of labor by a healthy adult. The convenient, concentrated energy of fossil fuels has helped raise living standards in much of the world. However, fossil fuels are dirty and not renewable; and the carbon dioxide added to the air when we burn fossil fuels is the principal cause of climate change. The conclusion is fossil fuel companies will become clean energy companies or simply go out of business, if we wish to preserve our remarkable planet and its unique life. This energy transition does not require a bloody revolution. We must instead harness our political systems to work for the common good. It is a challenge, but one that young people can approach with confidence, not with fear or worry. My hope is to provide information that young people, especially those who become leaders, will find useful in meeting this challenge. Over the past half century I witnessed developments in the climate, energy and political systems. I believe that some of my experiences help illuminate the actions required to stabilize climate. You can assess that for yourself.

Acknowledgments: besides Anniek, I am indebted to many others. The ‘Iowa mafia’, especially Andy Lacis and Larry Travis, helped get me started. Makiko Sato’s many talents and dedication kept our work on track. Gary Russell, the architect of our climate model, provided the main tool that Reto Ruedy, Makiko and I used to help develop an understanding of climate change. Eunbi Jeong provides me the hope that our current research group – Pushker Kharecha, Craig Rye, Makiko, Eunbi and me, and attorney Dan Galpern -- may yet make a difference.

4 © 2020 James Edward Hansen. All Rights Reserved.

Picture of the William Tapscott in Mariners Museum, Newport News, Virginia

Chapter 1. Ancestry Ingvert and Karen Hansen, my father’s grandparents, emigrated from Denmark in 1860. Ingvert was born in Ribe County, Lihme, in rural Denmark in 1836. At age 19 he was converted to the Latter Day Saint (LDS) religion1 by Mormon missionaries. He served four years as a Mormon missionary while he worked as a carpenter in Denmark. At age 23 he married Karen Pietersdaughter of Holme, Denmark, and in 1860 they used her small inheritance to pay for their trip to America, where they hoped to contribute to the building of Zion, the Promised Land. Ingvert, Karen and 729 other ‘Saints’ – converted Danish, Swiss and English Mormons – set sail in May 1860 from Liverpool on the William Tapscott, a three-deck sail ship usually used for freight. With unfavorable winds, the trip took 35 days on rough seas, during which 10 passengers died, 9 marriages occurred, and four babies were born, one of these to Ingvert and Karen. They named their first child William Tapscott Bell, after the ship’s captain James Bell, which may have helped assure that the newborn was declared an American citizen by the captain. The captain had sole authority to declare whether a child was born close enough to shore to be a citizen. The most arduous leg of their journey, by oxcart from Omaha to Utah, required 2½ months. They reached Salt Lake City in October 1860. Ingvert’s carpenter tools, carried from Denmark, aided their pioneer struggles in the forbidding Utah landscape. But Ingvert and Karen became disillusioned with Brigham Young’s version of the Latter Day Saint church, especially its polygamy (more precisely polygyny, plural wifism). From an apostate Mormon, Alex McCord, they learned about a smaller offshoot of the Latter Day Saint church – the Reorganized Church of Jesus Christ of Latter Day Saints, RLDS2 -- with members located mainly on the eastern banks of the Missouri River in Iowa and Missouri. The RLDS religion was closer to the church the Hansens thought they were joining when they left Denmark. So in 1864, now with three children, Ingvert and Karen set out with their oxen on the Mormon Trail in reverse. Their goal, on the advice of McCord, was to homestake in western Iowa, which in 1864 was tallgrass prairie, with tree groves growing mainly along the streams.

5 © 2020 James Edward Hansen. All Rights Reserved. Upon reaching southwest Iowa Ingvert and Karen settled in Gallands Grove3, in the northwest corner of Shelby County about 15 miles southwest of present day Denison. A majority of the settlers already in the Grove were Mormons who had been driven from their homes around Nauvoo,1 Illinois, but had decided not to follow the Mormon leader Brigham Young to Utah. The Hansens were nearly penniless, but according to Shelby County history, Alex McCord made it known that the Hansens were “hard workers, good credit, and needed help in getting settled.” The homestead may have appeared to be Eden compared to Utah, but it was hilly, rocky land, difficult to plow. Some years the crops were lost to a grasshopper plague, chinch bugs, or drought and dust storms. It was not all bad, though: chickens and pigs fattened on the grasshoppers. Ingvert and Karen never strayed far from the Grove. The eighth of their 11 children was James Edward Hansen, my grandfather, known as Jim Hansen. Our ancestry on my father’s side of the family is documented by my oldest sister, Donna Hansen Stene, in The Hansen Family.4 My grandfather, Jim Hansen, married Katherine (Kate) Von Tersch. Kate was daughter of Johan Von Tersch and Mary Wilwerding, immigrants from Westphalia, Germany and Belgium, respectively. Jim and Kate had eight children, the second being James Ivan Hansen, my father. I wanted to do a simple calculation of the countries of origin of ‘the blood in my veins,’ assigning 25 percent to each of my four grandparents. My father’s side would imply that my siblings and I are 25 percent Danish, 12½ percent German, and 12½ percent Belgian. Donna has done a lot of work on our mother’s parents, John Ray and Florence Longenecker, but the story on that side of the family is complicated. The Rays go back five generations to Orville, Alsace, which is in France today, but is a region that was fought over for centuries and was alternately German and French. The Longeneckers go back nine generations to the Emmental valley of Switzerland and the Palatinate in southwestern Germany. Donna points out that several of the wives were German in the marriages of the several generations of my mother’s ancestors, and Donna concludes “we are definitely more German than Dane!” DNA evidence has Germanic Europe at about 50 percent, Great Britain second and Scandinavia third. This ancestry will be of interest to me, when I later consider the roles of Germany and the United States in creating the climate debacle that young people face today.

Pioneer great grandfather Ingvert Hansen left almost no writings. We are only aware of his diary for parts of the travel from Denmark. We know that his farming in the ‘hardscratch’ Grove soil was arduous, but he had five sons to help with the farming, as well as six daughters to help his wife, Karen. He likely retained his strong religious bent, as he eventually became the presiding Elder in the RLDS church in the Grove. Our best source of information about Ingvert’s character, my sister suggests, may be the inscription on his gravestone, which reads: “An honest man’s the noblest work of God.” One story from Ingvert’s pioneer days has been passed down the generations.

6 © 2020 James Edward Hansen. All Rights Reserved.

Yellowsmoke photograph from newspaper article handed down by our father. The article described Yellowsmoke as between six feet and six feet two inches in height and weight 200-230 pounds.

It’s about Yellow Smoke, Chief of the Omaha Indians. Chief Yellow Smoke was the keeper of the Sacred Pole, the centerpiece of ceremonies, subject of sacred songs, and symbol of the tribe’s well-being. Yellow Smoke’s name came from the yellow smoke stain on the pole, which was displayed in the Smithsonian Museum in Washington, D.C., and now rests with the Omaha Tribe at Macy, Nebraska, according to the Crawford County History website. Yellow Smoke often visited the farms of Ingvert and his neighbor, John McIntosh, who was one of the first settlers in Shelby County, in 1849. It is possible that McIntosh and Ingvert tried to convert Yellow Smoke to the Mormon faith, as both Joseph Smith and Brigham Young advocated that approach. In any case, Yellow Smoke expressed a desire to be buried “like a white man” in the Grove. He got his wish much sooner than he would have wanted. The most reliable account of Yellow Smoke’s demise, in my opinion, is the story passed from Ingvert to later Hansen generations. Sparsely settled western Iowa changed rapidly in the second half of the 1860s when a railroad was built across the state, reaching Council Bluffs in the fall of 1866. The town of Dunlap on the Boyer River several miles west of Gallands Grove sprang into existence in 1867, after the town was platted by a railroad company. The second building constructed in Dunlap was a saloon named Respectable Place5. Chief Yellow Smoke took a liking to gambling and drinking with white men in Dunlap. According to my ancestors, Yellow Smoke was mortally wounded after demanding his winnings from a card game, the winnings being 75 cents. An argument and scuffle ensued during which Yellow Smoke was struck on the head. The blow crushed his skull. Yellow Smoke managed to reach Gallands Grove, four miles east of Dunlap, where Omaha Indians were encamped, but he died several days later and was buried in the Grove. An article in the New York Times on 5 December 1868 says that after Yellow Smoke was struck and injured on the evening of 27 November “He succeeded in getting to where there were several hundred Indians encamped, about four miles east of town. He expired on 7 © 2020 James Edward Hansen. All Rights Reserved. Wednesday morning.” Wednesday was 2 December 1868. The Times story also notes “The Chief was always noted for being very friendly and strictly honorable. His band comprises some 1,500 warriors, who according to reports are gathering in fast and are greatly excited. Yellow Smoke was buried yesterday.” According to my father, Yellow Smoke was buried on Ingvert’s property. William, Ingvert’s oldest son, acquired most of Ingvert’s property, and passed it on to his son, Billy. William, born on the boat on the way to America, was 8½ years old when Yellow Smoke was murdered. According to Billy, Yellow Smoke was buried under a tree on Ingvert’s property, and subsequently they were never allowed to plow close to the tree, because of the grave. An article in the 15 June 1978 Harlan Tribune says that Indians continued to visit the grave and camp on the sacred ground as late as 1922. That article suggests that the grave may have been on the McIntosh property, but I believe that the information passed from William to Billy is more credible than a newspaper article discussing what it describes as a “legend.” The Yellowsmoke story and pioneer writings are relevant to later discussion.

Gallands Grove and surrounding areas changed enormously during the first two generations of settlers. We have no writings by Ingvert or his wife Karen describing their Iowa homestead. However, the Grove sits near the adjoining corners of four counties: Crawford, Shelby, Harrison and Monona. Historical data for these counties provide helpful information, especially a 488 page history of Harrison County5 that contains reminisces of several early pioneers, including D.W. Butts and Sally Young: Pioneer Butts decried the loss of the deep-rooted 6-foot prairie grass that, except for the occasional tree grove, once covered western Iowa, noting that the prairie grass was succeeded by 2-foot “tame grass” and weeds. He wrote “The grass, the natural product of this valley, was so high and luxuriant for miles and miles that horsemen might hide from each other at a distance of two hundred yards. Quite as surprising as this true statement is the rapid change by which this tall grass disappeared very quickly after the white man appeared with cattle and crowded out the deer and the elk and the red men. We expected to see the range gradually reduced, but were hardly prepared to see it go down from six feet to two feet in a few years. However, the wild hay of this section has been a mine of wealth to many, and it is yet to those who had the foresight to save it from the flock and plow. Forty years ago this part of the state was noted for grass and hay, as it is now for corn and hogs!” Pioneer Sally Young wrote: “We located in this county in 1850 and found, as we thought, the garden of Eden, a vast prairie of beautiful flowers and a great abundance of wild fruits. At this time the country was very thinly settled, our nearest neighbors being six miles away.” She complained about the flies and mosquitoes, but continued “There were oceans of game, tons of fall acids in the shape of plums and grapes. The thousands of deer which roamed up and down the valley…were to be had at the little cost of shooting and dressing, and gave to the larder all, yea, perhaps, better than is now experienced by many, who at present live in this, what is termed the land of plenty. Great droves of wild turkeys lined the skirts of the interior timber track, and honey was far more plentiful then than now.”

8 © 2020 James Edward Hansen. All Rights Reserved.

Antarctic temperature in the past 800,000 years relative to the Holocene average.

Modern agriculture succeeds in feeding a large population. Yet it has flaws that affect human health and the environment. There is something to be learned from the natural tallgrass prairie. Here let us note that there are potential improvements to current agricultural practices that would help restore biological diversity and increase soil productivity while also storing more carbon in the soil, changes that would help limit human-made climate change.

D.W. Butts wrote of “red men,” who were called Indians when I was a boy, or American Indians when corrected by our school teachers, or Native Americans today. First Americans may be more appropriate, but I will use the popular name. By the late 1800s Native Americans in western Iowa had been moved forcibly to less productive land west of the Missouri River. Let us finish our initial remarks about Native Americans with one poignant paragraph from the Harrison County history,5 titled there as “Indian Troubles” “The last difficulty with Indians in this part of the country was in 1885, when a band of about three hundred were in the habit of crossing the Missouri river into Harrison county. They were quite friendly, but annoyed the citizens very much by pilfering stock and poultry. To put a stop to this the whites, twenty in number, assembled and met the band when they had crossed the river. The twenty whites captured the three hundred Indians, loaded their bows and arrows into wagons and took them over the county line at Honey Creek, Pottawattamie county. The Indians were half starved, and the humane white people gathered together and raised a fund with which a steer was bought and given the Indians, who seemed to greatly appreciate the act of kindness. After the feast, the day following, they went over the river to their homes in eastern Nebraska.”

“Kindness of the humane white people” is Butts’ perspective. Let us recall the long history of Yellow Smoke’s ancestors in America, in the context of human history. First archeological evidence of humans, homo sapiens, is from Africa about 300,000 years ago. The spread of humans into Asia and Europe occurred at least 60,000-80,000 years ago,6 probably earlier, but the Pacific and Atlantic Oceans isolated the Americas, which remained free of humans until late in the last ice age, just preceding the current interglacial period, the Holocene. Earth’s climate varies naturally by large amounts, as shown by the chart of Antarctic temperature change over the past 800,000 years. Climate change on these time scales is global in extent, with global average temperature change about half as large as the Antarctic temperature change.

9 © 2020 James Edward Hansen. All Rights Reserved.

Beringia land extent included the green area during the ice age.

During the last ice age, which peaked about 20,000 years ago, a large ice sheet covered most of Canada and northern parts of the United States, including the locations of Seattle, Minneapolis and New York City. There was a smaller ice sheet in Eurasia. So much water was locked in these ice sheets that sea level was about 125 meters (400 feet) lower than today. Lower sea level caused the continental shelf area around Alaska to be above sea level. Humans were becoming capable of living in cold climates, and people moved into Beringia. This land had shrub vegetation, trees and large animals, which provided fuel and food. Archeology and genetics suggest that Beringians were isolated for several thousand years, but, as ice began to melt, they could move freely. Beringians were the founding people of North, Central and South America.7 These Native Americans occupied the Americas throughout the Holocene. When Columbus arrived, just half a millennium ago, there were about 10 million Native Americans in what is now the United States, and perhaps 50 million throughout the Americas, with these populations uncertain by about a factor of two. Immigrants from Europe wiped out more than 90 percent of the Native Americans, via diseases they brought and warfare. Mistreatment of Native Americans is now historical fact. We often deal with uncomfortable facts by briefly noting them in our textbooks, then putting them out of mind, perhaps believing that we cannot change history – but tomorrow’s history is being written today.

Nature’s Corridor is a dream today, a concept of contiguous land stretching north-south from the Arctic through North, Central and South America, land that allows free migration of wildlife. The Corridor might permit partial restoration toward conditions that existed during earlier Native American history, while being consistent with the pioneers’ notion of a range ‘where never is heard, a discouraging word, and the deer and the antelope play.’ E.O. Wilson proposes8 that half of Earth’s land be designated a human-free reserve to preserve biodiversity. Much of Wilson’s objective could be achieved with a region in the American West that grows over time, encompassing some existing reserves and national parks.

10 © 2020 James Edward Hansen. All Rights Reserved. Climate change and other human-imposed stresses on nature create an urgent need to find a plan for species preservation. Climate change also draws attention to the potential for restoration of tallgrass prairie and forests to contribute to drawdown of excess atmospheric carbon. Native Americans have relevant knowledge and interest in restoring the land. Could Native Americans help devise and implement a plan to restore part of our land to its natural richness, provide habitat for wildlife, and draw down atmospheric CO2? Nature’s Corridor could be a basic plank in the platform of a political party that aims to restore the American dream. Let’s consider that topic later.

I struggled to write the next chapters of this book. I wanted to describe my life growing up in Denison, Iowa. Denison was a wonderful place to grow up. Our mother told us many times how lucky we were, and she was right. Yet I wanted to know more about my parents’ struggles as they tried to provide for their family. I dug into the 390 page The Hansen Family4 written by my oldest sister, Donna Hansen Stene, and her husband, as well as 62 pages of unpublished vignettes9 on our childhood written by my second oldest sister, Eleanor Hansen Maiefski, who was the story-teller in our early days of exuberant child-filled bedrooms. Their stories raised more questions, which led to hundreds of e-mail exchanges with all of my siblings, providing their remembrances and frank assessments. As I learned more about my parent’s early life, it seemed that they had inherited a situation with the odds stacked against them. Something strange must have happened during my grandparent’s generation, the generation that followed our pioneering great grandparents, Ingvert and Karen Hansen.

11 © 2020 James Edward Hansen. All Rights Reserved.

James Edward Hansen (my grandfather) and his bride Catherine (Kate) Von Tersch in 1902 Chapter 2. Grandparents Pioneer Ingvert died young, at age 52 in 1889, leaving James Edward (Jim) Hansen, my grandfather, not yet 16 years old, as the man of the house. Ingvert’s two older sons had already married and established their own farms, with Ingvert’s assistance. Jim Hansen inherited a big responsibility. His mother, two older unmarried sisters, two younger brothers, a younger sister, and he composed the household of seven. The responsibility of running the farm and supporting a large family was a lot to expect from such a young man, but, ably assisted by his younger brother George, Jim kept the farm functioning in a difficult time. Ingvert’s widow, Karen, inherited the farm. Four years after Ingvert’s death, Karen sold some of the farmland to allow purchase of three acres of land in nearby Woodbine. Jim used a horse and wagon to haul lumber from Council Bluffs to the three acres in Woodbine, where he built a house for Karen and a barn, where Karen kept her horse and a cow. It was a remarkable accomplishment for a 20-year-old. Karen moved to this house with the two youngest children, so they could attend the town school and obtain a secondary education. Jim continued to farm the Hansen property, paying rent to his mother. In 1902, at age 29, he married Catherine (Kate) Von Tersch, age 19. Kate, one of 13 children, bore seven children in the first 10 years of their marriage. The second child was my father, James Ivan Hansen. When Karen Hansen, the pioneer, died in 1915, the farm was auctioned for the benefit of all of Ingvert and Karen’s children. Jim tried to purchase part of the farm, but was outbid.

Failure to acquire the homestead was a tragedy for Jim. He had spent his entire life there, more than 40 years. He had been farming the property for 26 years, since Ingvert died. After losing the homestead, Jim acquired a smaller farm on credit and took to drinking in Dunlap on Saturday evenings. He was a powerful man. When disputes flared up, they were often settled with fists. The shape of Jim’s nose testified that he took blows, as well as delivered them. My father and his brothers also suffered blows when Jim came home after drinking. They learned to disperse, hiding in the cornfield, when he was in that condition. 12 © 2020 James Edward Hansen. All Rights Reserved.

James Ivan Hansen (age 42), James Edward Hansen (5), and James Edward Hansen (73) in 1946.

Jim was able to terminate use of alcohol during the Great Depression, but bad weather, poor crops and depressed prices led to the loss of all but a sliver of his farmland. Jim and Kate were living in a two-room shack, without siding on the outside or drywall on the inside, when my family visited them in the late 1930s and the 1940s. Yet even the Depression did not prevent happy family get-togethers on holidays. My older sisters remember how Kate ran out joyfully, with her apron on, to greet us when we arrived.

The final tragedy to befall Jim Hansen, from which he never recovered, was the early death of his wife Kate in 1943, from a stroke at age 59. Grandfather Hansen continued to live several years in the shack. When we visited, he would sit by his desk, where he had a copy of the Bible and the Book of Mormon, and read from or quoted them. When he spoke everyone was quiet. I don’t remember what he said. He had a tin of candies on his desk. He would take the lid off and hold out the tin to offer the candies. His hands were very large and strong, but they were quivering so much that the candies were all jostling against each other and against the side of the can. They were mints. Family pictures were taken in Sunday-best clothes. The photo above was taken in Defiance, Iowa, where several members of the Hansen family lived at that time. The building in the background is the school. This was the time in my grandfather’s life when I remember him. Two generations – of pioneers Ingvert and Karen and my grandparents Jim and Kate – span the change of western Iowa from tall-grass prairie with groves of trees, shared by a handful of pioneers with Native Americans, to a nearly modern landscape of agricultural fields divided by roads and highways with fast-moving automobiles. How consistent are the experiences of those two generations with the myth of American westward expansion by white pioneer farmers?

Laura Ingalls Wilder’s Little House on the Prairie has spawned generation after generation of ‘bonnetheads,’ readers entranced by her stories about life in the prairie, chronicling the broader story of westward settlement by white American farmers. Little House is fiction, but Wilder, 13 © 2020 James Edward Hansen. All Rights Reserved. when asked by readers whether the stories were ‘true’ generally answered that they were in the main truth as she knew it. Caroline Fraser, in Prairie Fires: The American Dreams of Laura Ingalls Wilder,10 confronts the fact that truth is malleable. Fraser asserts that by sanitizing the story of westward settlement, Wilder contributed to myth-making that flourishes in American history and politics. Little House was written for children and young teens. It was among the books devoured by my sisters as they were growing, encouraging them to read more. Wilder’s stories present youth with a picture focused on positive values, such as hard work, perseverance and devotion to family. She describes successful struggles to overcome great pioneer hardships. Little House and similar books are fine for young people – my own children and grandchildren were raised on them. However, at a reasonably early age, children need to be told about major omissions. I already mentioned the cruelty of forced Native American removal, an injustice that, at least to some degree, might still be addressed. A second issue I’d take with the expansion of farming into the prairie is the wisdom of replacing rain-limited prairie by small-scale family farms. The government encouraged this expansion by practically giving away the land parcels. One of the consequences has been a loss of soil carbon and topsoil, as deep-rooted tallgrass prairie is replaced by shallow-rooted crops and the soil is plowed repeatedly. Appropriate agricultural practices can alleviate this problem, and such changes are needed as part of a program to stabilize climate.

Ingvert’s generation was closest to the picture of frontier life presented in Little House. Following generations suffered the predictable problem of fragmentation of property because of large family sizes. Hardships for these small farms increased as the industrial revolution allowed mechanization of farming and altered the scale of the most efficient farms. Even great hardships can be overcome. Hard work and strength of character help. A new generation can bring new dedication. Love, including love of the farming life, provides a fuel, the energy that can overcome even the most daunting challenges…perhaps.

14 © 2020 James Edward Hansen. All Rights Reserved.

Gladys Helen Ray, a determined, indomitable woman, at age 19.

Chapter 3. Parents on Five Farms

My father, James Ivan Hansen, known as Ivan, attended a one-room country school. His formal education ended with eighth grade, an adequate education by local custom. Reading, writing and arithmetic were learned well; handwriting was practiced until nearly perfect. Young men were strong enough by eighth grade to work on the farm. They helped at home and hired out for work on other farms. My mother, Gladys Helen Ray, was raised on a farm several miles from Hansens’ farm. The Rays had larger, more productive property, but their health did not match that of the Hansens. Gladys was two years old when her mother was discovered to have breast cancer. After years in pain, her mother died when Gladys was 12. Just two years prior her father had died in the 1919 Spanish influenza epidemic. Meanwhile, her grandparents had died. Between the ages of 8 and 12, surely a crucial period, she witnessed terrible illnesses of both parents and lost all the adults in her life. Gladys was early an excellent cook, learning Pennsylvania Dutch cooking from her grandmother and mother. When her mother was dying, Gladys prepared her meals. Even when my mother was old, she could still remember the contents of her mother’s last meals. The final meal was eggs, which her mother asked her to prepare the way only the two of them could. Gladys and her older brother were taken in by a distant relative, second cousin Jack Hunter and his wife Daisy. Her brother ran away immediately and was henceforth on his own. Hunters had four children, ranging from newborn to six years old. Orphan Gladys became domestic help for the Hunters, interrupting her schooling to work fulltime for them. After a year she was able to return to school, while continuing her domestic help for Hunters. She walked more than two miles from the farm to the Dunlap school, but when she was older she was sometimes allowed to ride a horse to school. At age 19, in 1930, she graduated from Dunlap High School.

Ivan Hansen, seven years Glady’s senior, likely worked for Hunters at times. Gladys fell in love with him. The Hunters did not approve of their marriage, because Hansen had neither land nor money. Within days after her graduation, Gladys and Ivan eloped and married on 15 June 1930.

15 © 2020 James Edward Hansen. All Rights Reserved. The Great Depression had begun. Farms were being consolidated and mechanized, while Ivan’s experience was with a horse and plow. Rundown farms were available for sharecropping or rent, but leases were temporary. Against these odds, my mother made a wonderful home. Her cooking was unrivaled. On each farm she planted a huge garden. Without electricity or running water, she canned and preserved hundreds of jars of tomatoes, corn, beans, and peas. Potatoes, beets, cabbage, onions and carrots were stored in a dirt cellar. She milked cows that our collie, Pal, brought home in the evening. She separated cream, to be sold, from milk, and washed the separator daily. She gathered eggs, and butchered and cleaned chickens. This was part of her ‘housework.’ Her energy seemed inexhaustible. Through frequent pregnancies, she worked up until the day of delivery. Her first four children were girls. She made dresses for the girls from colored cotton feedbags. Donna, the oldest, became my mother’s helper. My sisters’ remembrances of the farm life tend to be joyful. Wildflowers and wild roses bloomed all summer along the dirt country roads. These were peaceful times, probably the best years of my mother’s life. She sang as she worked in the garden. We were a growing family, isolated but together. We lived on five farms in the period 1930-1945. In some sense, life on the successive farms became a downward spiral. Donna, born in May 1931, has memories of all five farms that our family occupied. My description of those years is based on writings already mentioned of my two oldest sisters and recent exchanges with all four older sisters.

Keairnes farm. The first farm was our parents’ best situation. For a moderate fee, they rented 40 acres of farmland from my father’s uncle Mindred Keairnes and his wife Laura Hansen Keairnes. The 40 acres included a small house located across the road from Keairnes’ home. Early years of our parent’s marriage were happy times. My mother’s small inheritance sufficed to purchase an automobile and contributed to purchase of a few farm implements. My father plowed the field using two horses. He used a two-horse hitch on his farm machinery, including the plow, manure spreader, corn planter and hayrack. Corn, oats and hay were the primary crops. Corn was picked by hand and oats were shucked by hand. Threshing was a cooperative effort with neighboring farmers. During a threshing session my mother prepared huge meals for the hungry workers. Chores had to be done every day. Animals raised were chickens, pigs and a few cows for milk. There were no vacations. Horses were special. While living on the Keairnes farm, we acquired Babe, a big, strong, black workhorse. Babe was our parents’ favorite horse, because she worked hard and was so reliable. When my father came in from the field he sometimes put one of my sisters on Babe’s back for the ride to the barn. We still had Babe on the last farm. She is the only horse I remember. Donna remembers watching Dad plow the field. He planted corn in straight rows diminishing like railroad tracks all the way to the far fence line. He was unhurried and tenacious, working for hours without talking. It was hard, hard work, back breaking and slow. Ominously, tractors planting many rows simultaneously were taking over on bigger farms Sundays were the time to wear “Sunday best” and attend a nearby church. When we lived on the Keairnes farm, we attended the Manteno Methodist Church, where many parishioners were actually RLDS (Reorganized Latter Day Saint) members. 16 © 2020 James Edward Hansen. All Rights Reserved.

Great Aunt Laurie (daughter of Ingvert) with author and sisters Eleanor, Karen, Lois and Donna.

When relatives visited, the food that my mother made usually included fried chicken, mashed potatoes with chicken gravy, homemade bread and pies. All agreed that nobody made better fried chicken than my mother. Everything was made from scratch – there were no ready-made mixes – and she amazed people by not using written recipes. She worked fast and had either memorized recipes or just had a feel for how much of each ingredient was needed. Smell from baking bread was itself delicious. When the loaves of bread and individual rolls came from the oven, with lightly browned tops and soft white insides, the taste matched the smell. The day usually finished with freshly cranked ice cream made with real cream.

Great Aunt Laura Keairnes had a profound effect on my sisters. Keairnes’ house had a porch with a rocking chair, where Aunt Laurie read to my oldest sister, Donna, and later to Donna and Eleanor, the next sister. Aunt Laurie also saw a need for at-home Bible school. Each week she arrived at our house, usually in a crisply starched gingham dress and sunbonnet, to read the church magazine, Zion’s Hope. She taught Donna the big words and Eleanor the small ones. Aunt Laura and Frank Crandall, Donna’s first teacher in a one-room schoolhouse, instilled a love of books and provided access to books. Grades 1, 2 and 3 were combined; Donna finished that class in two years. Mr. Crandall visited our home many times and allowed Eleanor to sometimes accompany Donna to school, even though Eleanor was not yet school age. Aunt Laura and Frank Crandall had initiated a consummate preschool education program. The reading infection spread to younger sisters via our mother’s method of child care: she instructed them to “play school” while she did her many chores. Each girl tried to catch up with the older one. In the evening the girls read from the light of a kerosene lamp on the kitchen table – none of our farms had electricity or running water. A few years later, when Karen, sister #4, was tested for reading she was placed in first grade, but when the teachers saw how small she was, two years younger than classmates, they put her in kindergarten. This life and farming method could not endure. Mindred Keairnes’ death hastened change. 1936 began a succession of moves from one rundown small farm to another.

17 © 2020 James Edward Hansen. All Rights Reserved.

Farm #3 (Ryan farm) near Dunlap and farm #4 near Charter Oak.

Dunlap farms. Lois and Karen, sisters #3 and #4, were born on the next two farms, near Dunlap, each farm occupied for two years. It was a difficult time to scratch out a living. Some years, with drought and dust storms, there was hardly any crop. With no money for gas, the car was put on blocks in the barn. Horse and wagon would do. Our father worked one year for the WPA (the Works Progress Administration set up by President Roosevelt) on a road and bridge near Dunlap. The family subsisted to a substantial degree on vegetables from the garden, which were stored in a dirt cellar and canned and preserved each summer for year-round consumption. There were also milk and eggs, and sometimes chicken, but these were also our primary source of income when crops failed, so they were consumed judiciously. The second of these two farms, called the Ryan farm, was 80 acres just half a mile from Dunlap. The house was on a hill overlooking the 80 acres. The land in front of the house sloped down to the Boyer River flood plain. Before the river there was the railroad track. It was the railroad, built in 1866, which brought forth the town of Dunlap, the Respectable Place Saloon – and the demise of Chief Yellow Smoke – as well as commerce that helped build the state. The railroad, and the Great Depression, brought hobos. My mother called them tramps. She was afraid of them. When Donna left to school in the morning, walking, our mother said “I hope the tramps don’t get her!” Eleanor, understood “traps” and thought of a giant mousetrap. She feared that her sister would be slammed in a giant trap and not return home from school. When our mother saw a hobo coming up the path, she pulled down the shades and locked the doors. If knocking persisted, she would say “We don’t have much. You have to eat what we do.” Then she would fry an egg, put it between two slices of her homemade bread, hand it out a hole in the screen door, and lock the door again. The hobos never caused any harm.

Charter Oak farm. We had to leave the second Dunlap farm in March 1940. My father found an available farm 15 miles away, near Charter Oak. The day after we arrived in Charter Oak our beloved dog, Pal, disappeared. Pal was obtained as a puppy in 1931, a gift from, Martha Bloom, the midwife at Donna’s birth. Pal was indispensable, herding the cows, protecting the children, and being our best friend. When she sensed danger, she barked loudly until our parents arrived. She was a beautiful collie, with long golden hair. Some of the golden hair was tipped with dark auburn, and there was a white ring around her neck. She looked much like Lassie in the movies.

18 © 2020 James Edward Hansen. All Rights Reserved. Eleanor tells how our sad-faced mother came to the girls bedroom that evening and had the three oldest girls (Karen was still a baby) kneel by the bed and pray for Pal. This was repeated each day at bedtime. My mother spent some of our scarce money on a lost-dog newspaper ad. After several days a message was received: Pal was seen “sulking” at the old farm. Somehow Pal had made it 15 miles from the new farm to the old one, ready to perform her chores. Pal jumped all over the girls and our parents when they arrived at the old farm to pick her up. Another of Eleanor’s remembrances concerned the Easter Rabbit in 1941. On the evening of 28 March all four girls were hustled off to the Kelm’s house, the closest neighbor, where they got to sleep for the first time in a bed with thick goose down blankets. In the morning Mr. Kelm told them that the Easter Rabbit had brought them a baby brother. He proceeded to make various offers in exchange for their brother, but with every offer they vigorously shook their heads. Anniek claims that my sisters spoiled me ever since then. In any case, I was lucky that our long- time trusted country doctor, Edward James Liska, arrived in time for the birth, as I was born breech with the umbilical cord around my neck, and Dr. Liska, had to deliver CPR. My mother thought of naming me Edward James for the doctor, but my father’s name choice prevailed. Economic conditions improved in the 1940s. Income from chickens, eggs, cream, and crops increased as America came out of the depression. We took our cream to the Charter Oak Creamery on Saturday evenings, where we were paid in silver dollars. On one trip to Charter Oak there was a sale on girl’s dresses. My mother bought one dress for each girl, 19 cents each. It was their first ‘boughten’ (store bought) dresses. On some of these Saturday trips our parents gave a buffalo nickel to each of my sisters. A nickel was good for one double-dip ice cream cone. The movie theater was just becoming popular, but a nickel was not enough for admittance. No matter. My sisters made their own entertainment. Eleanor was a natural story-teller, making up stories out of whole cloth. To escape chores she would agree to make up a play with parts for each sister. After they had a chance to ‘edit’ their pieces, they would act out the play. Sometimes a barn kitten or farm animals were included in the plays, and once there was a marriage of young calves. The only songs they knew were Christmas carols and hymns, which did not always fit. A country schoolteacher usually boarded at one of the nearby farms for the school week. My sisters bitterly lament that in our last year in Charter Oak, we drew the short straw and had to board the teacher. One evening my mother saw the teacher and my father exchange a note, which my mother demanded to see. My father tossed it in the fire, whereupon my mother announced that she was leaving and drove away in the car. I was too young to be aware, but my sisters went to bed in fear. Our mother was present for breakfast, but a tension that would grow was in the air. The Charter Oak farm was owned by an insurance company, which told us that we had to leave in early 1944. We had not found another farm by the usual 1 March moving day. Fortunately, the teacher came back from the weekend with scarlet fever and I caught it. It gave Dr. Liska a reason to quarantine us for three weeks, and it gave my father time to search further.

Denison farm. My father found a farm, 40 acres, on the outskirts of Denison, the first farm on the left on what is now named Donna Reed Road, just off Highway 30. Not far up the road was the Denison golf course and Country Club. We lived on this farm only for a year. 19 © 2020 James Edward Hansen. All Rights Reserved. In early summer of 1944 I had a medical emergency. I persisted in crying, with a stomach ache, so my mother delivered her standard remedy: an enema. If my appendix had not already burst, it did then. As my wails increased, my mother gathered me up and we headed off to Dr. Liska. Six-year-old Karen went with us. She says that I laid on the back seat of the car, crying loudly the entire 20-mile trip to Ute. Dr. Liska sent us straight back to Denison, to a hospital and surgeon. I now have a 5-inch scar marking the doctor’s work. I promptly developed pneumonia. According to my two oldest sisters, I survived only because penicillin had just become available. Most of my mother’s remedies, for people and animals, were good and skillful. Queen, the latest companion workhorse to Babe, limped into the farmyard with blood pouring from one leg. She had tangled with a barbed wire fence. Our mother quickly lowered the leg into a cream can filled with flour and made a tourniquet with a dish towel. The veterinary praised her work. Another time our cows broke a fence and got into a field of fresh alfalfa, gorging themselves to the point of severe bloating. The life of one was in danger. Our mother shaved an area on the cow’s belly and inserted a sterilized knife. The bloat was relieved and the cow lived. During the night of 18/19 August 1944, while all five of us children were sleeping upstairs, my mother began making so much noise downstairs that two of my sisters woke up. They huddled, trying to figure out what was happening downstairs. It was my mother moaning in childbirth with a midwife present. Then male voices, as my father arrived with Dr. Liska. The next morning we found our mother in bed with baby Patty, my fifth sister. Lois remembers the pail of bloody water and gunk. It was our last home delivery. The farm was not as productive as my mother. The Boyer River flooded, ruining the crops. Fortunately my father got a part-time job as a bartender at the country club across the road. Both parents had lived their entire lives on farms and loved outdoor life. The thought of leaving the farm was heartbreaking. But my father’s physical strength was declining and he had chronic back pain. Farming that year had been money-losing, with little prospect for improvement. My father was offered a bar-tending job in Denison. Moving to town was the only path forward. Our mother did not seem normal on the day of the farm’s auction; she seemed worried. She asked Eleanor to help introduce people to each other when they came up the driveway to the barn. They seemed to be mostly neighbors or relatives. We did not have much farm equipment, but they were things that my father and mother had scrimped and saved for all their married life. The auctioneer’s chanting became too much for my mother. She went to the house and watched from a window. As a buyer led Babe down the lane, tears streamed down my mother’s face. Although opportunities grew when we moved to town, so did anxieties as life became more complex. Not all change would prove to be for the good.

20 © 2020 James Edward Hansen. All Rights Reserved.

Chapter 4a. Denison, Iowa: It’s a Wonderful Life

Denison was a wonderful town to grow up in and go to school in. It was almost quintessential America. The American dream of equal opportunity for all was nearly true. As for me, I failed to take advantage of the opportunities. Even though it was a different era, maybe some insight can be gleaned from a character seemingly uninterested in growth. Denison sits calmly on a hill, one of the hills pushed by the snout of massive, mile-thick, slow- moving glaciers that descended from the north time and again, stealing soil of Canada and Minnesota, depositing it in heaps11 in the American Midwest. Denison sits within the acute angle formed by the lazy Boyer and East Boyer Rivers. The rivers meet just southwest of town and flow as one, still lethargically, in a southwesterly direction to join the Missouri River. Denison was established in 1856 by an enterprising New Yorker, Rev. Jesse Denison. It was a decade before the railroad arrived, but Rev. Denison expected the railroad to run along the flat Boyer River valley. Rev. Denison was an agent of the Providence Western Land Company, which used elaborate advertising, depicting steamboats at anchor on the Boyer River, to induce eastern capitalists to invest $51,000 in the company. In reality the Boyer could only float a steamboat moving downstream during a spring flood. Some of the money was used to purchase land warrants from military veterans. The U.S. government had issued warrants of up to 160 acres to veterans of the war of 1812, the war with Mexico, and some “Indian” wars.12 Veterans could claim a homestead or sell the warrant. Rev. Denison paid as little as 60 cents per acre. Rev. Denison had a “way” with officials, according to historian Roscoe Lokken.13 Denison met with the federal agent in charge of land disbursement prior to the day on which claims could be staked. On that day, Denison was allowed to have the first hearing, during which he laid claim to a 23,000-acre site in the Boyer River fork, defining the town that bears his name. Next he got Judge John R. Bassett to locate the Crawford County Court House on the Denison hill, after agreeing to purchase 300,000 shingles from the judge at a price of $3.50 per thousand. The judge, on the side, had a shingle business. Normally such ‘arrangements’ are discreet, but in this case Rev. Denison’s papers describe the deal in a signed letter in which he cautions “This between you and me – and I would not have it said between others.”14 Denison’s first settlers were native-born Americans of English and Scottish extraction. Next came Swedish immigrants, soon overwhelmed by Germans. Die Denison Zeitung was launched 21 © 2020 James Edward Hansen. All Rights Reserved. in 1879, and soon thereafter an independent German newspaper, Der Denison Herold. There were so many Germans in the Denison area that the 775-seat Deutsche Opernhaus Gesellschaft von Denison was built in 1914 at the corner of Main Street and Broadway. By the time I was a youth in the 1940s this had become the Ritz Theater with adjoining Candy Kitchen and soda fountain. The most famous Denisonite, born in 1921, Donnabelle Mullenger, was of German heritage. In Hollywood, she changed her name to Donna Reed. She won an Oscar for her performance in From Here to Eternity, but is probably better known for her role in It’s a Wonderful Life, the 1946 Frank Capra Christmas movie classic in which she co-stars with Jimmy Stewart. She had her own The Donna Reed Show on television from 1958 to 1966. The Denison water tower broadcasts above the treetops: “Denison “It’s a Wonderful Life”.” The Ritz Theater is now transformed into the Donna Reed museum. An effort has been made to make the Denison streets resemble those of Bedford Falls, the town depicted in It’s a Wonderful Life. The Denison of my youth seemed as sturdy and commendable as Bedford Falls. At the base of Denison’s hill, Highway 30 ran from New York to San Francisco. Called the Lincoln Highway, it was America’s original cross-continental highway. At the top of the hill, Broadway also runs east-west, so Highway 30, four blocks south of Broadway, is Fourth Avenue South on street signs. Main Street runs down the hill, perpendicular to Broadway. On Lincoln Highway in 1945, not far from the intersection with Main Street, there was a bar, Russell’s Place, with a jukebox and good cheer, where my father became a bartender. A few blocks to the west, at the southwest corner of Denison, was Cronk’s Café, a place known to truckers from coast to coast, where my mother, a few years later, would become a waitress. These places provided fuel for a rage that would tear our family apart.

Our peaceful family life became chaotic after we moved to Denison in March 1945. The move brought an instant improvement of facilities. None of the farms had electricity. Only one, the Denison farm, had water in the house, via a kitchen lift pump connected to cistern water. Our Denison house had electric lights and one water faucet. The faucet was above a rectangular sink in the corner of the kitchen. That kitchen sink was shared by all eight of us for personal use, and eight became nine when my brother Lloyd was born in 1946. Oddly, I do not remember ever fighting over use of the sink. I suppose that we were very efficient in washing our faces in the morning, and we were happy about the upgrade from farm life. Our house had been moved to 318 North 11th Street, at the west end of town, the year before we bought the house and property. One of our new neighbors, Fred Nemitz, says that the house fell off the truck part way up 11th Street, a rutted dirt road. The fall caused a crack that ran from the ceiling to the floor in the wall between the kitchen and living room. We papered over the crack in the living room, but the crack was always visible in the painted kitchen wall. The house, as moved, had four rooms: two small bedrooms and a kitchen and living room. This house was placed over a hole in the ground to provide a cellar under one bedroom and the kitchen. The cellar was useful for storing canned produce from the garden for year-round consumption. Two rooms were added onto the house: a small bedroom, which our parents used, and a porch, used mainly for storage, as there was only one closet in the house. 22 © 2020 James Edward Hansen. All Rights Reserved. Baths, not too frequent, were in a round tub in the kitchen with water heated on the cookstove. It was a lot of work to change the water, but I don’t think we all used the same water. If my older sisters took such baths, it was after we younger ones were in bed. Personal modesty was the rule in the 1940s and 1950s. I remember seeing my sisters in bras, but never once with bare breasts. Our toilet situation did not improve immediately: we still used an outhouse. The way that works, the outhouse is placed over a hole in the ground. When the hole is half full, the outhouse is tipped over, a new hole is dug, dirt from the new hole is used to fill in the old hole, and the outhouse is placed over the new hole. Fortunately, after two years in Denison, we got a toilet in the corner of the cellar, connected to a septic tank. Unfortunately, the only access to the cellar was via outside steps down to the cellar door, and the path from our house’s backdoor to the steps was often muddy. This was still our plumbing situation when I was 18 and left to college.

Why describe our meager economic situation? I contend that opportunities for youth in low income families were much better in that era than today. Deterioration of educational opportunities is a correctable government failure. I failed to navigate school and social matters well, so I was academically far behind when I got to college. You need to avoid the mistakes I made. It is difficult to make up for mistakes later – you do not have the time to waste. Denison had tremendous money-making opportunities for kids. Columbia Hall, a dance hall, was one block from our house. Cars filled the parking lot and lined North 11th Street on Saturday night. Coca-Cola and Seven-Up bottles, discarded from vehicles, were worth three cents each, and beer bottles two cents. People returned to their cars to talk or make love; they did not seem to care about the three cents. The next morning we got a haul of bottles sufficient for several of us to see a movie at the Ritz Theatre and even get candy at the Candy Kitchen before the movie. Other money-making activities were paper routes, babysitting, table waiting, dish washing, pin setting at the bowling alley, and tutoring. Lois took me on her paper route when I was in second grade. I remember freezing toes and fingers in winter, but sometimes a sympathetic person invited us in for hot chocolate. In third grade I got my own paper route delivering the Omaha World Herald, about a dozen customers that Karen gave me from her bigger route. The price of the paper was 25 cents for six daily papers and 15 cents for Sunday. I paid 20 cents for the dailies and 12 cents for the Sunday paper, so I made eight cents. Profit was about a dollar a week, and increased as the route size grew. Donna lead the way and was a dynamo at making money. She was 15 when she got a job as a waitress at the Spot café. Then she got a more lucrative job as a telephone operator, although she had to stop temporarily when they found out she was underage. From her jobs as a waitress and telephone operator she made enough money to buy us a refrigerator on time payments. Before that, our neighbor, Mrs. Lohrmann, let us use her refrigerator to make jello. Thanks to Donna, we had our own luxury. Donna graduated from high school at age 17. She then worked for a year to save money to go to nursing college in Sioux City. After she left for college in 1949 there would be no luxuries, as our father’s salary could hardly support the remaining family of eight people. A wrenching event occurred between our parents during a year-end holiday season. Mr. Potter, owner of Russell’s Place, ran out of his best whiskey, the one he liked to use when he gave his 23 © 2020 James Edward Hansen. All Rights Reserved. best customers a drink during the holiday season. There was a limit on purchases from the liquor store uptown, even for a bartender, but because my father was a teetotaler, his ration was available. Mr. Potter gave him $12 for two bottles. My mother tried to help, by making the trip to the liquor store. My sister Karen was with her when she bought the two bottles. Unfortunately, as they went to the car, it was icy, my mother slipped, dropping a bottle and as she tried to catch it, she dropped the other. Both broke. Our father was furious and merciless. Mom came home and wept uncontrollably on Donna and Eleanor’s bed. It was traumatic for mother and the children who witnessed it. The event gradually receded, but was never forgotten.

I was eight years old, starting 3rd grade, when my mother took a job at Cronk’s Café. My father was enraged. My parents’ arguments occurred mainly after we children were in bed, but it was a small house and when his voice rose in anger I woke up. My father pounded the table with his fist, shouted a vehement curse against the owner of Cronks, and demanded that she stop working there. I feared repetition of the fights, which occurred several times. One night I had a dream: my father, in a fury, was shooting the cookstove with a blunderbuss. There was a huge hole in the stove, smoke was pouring out. I sat up in bed screaming repeatedly “no, not the cookstove!” It woke my parents, but not 5-year-old Patty and 3-year-old Lloyd, who were in the same bed with me. Then I realized I had been dreaming. My father was standing by our bed. I was afraid. I laid back down and pretended to go to sleep. He went back to bed. I had misunderstood their arguments about the stove. I was attached to the cookstove, perhaps because it was my job to bring in fuel for it, a basket of corn cobs from the cob pile in the backyard. My mother actually wanted to get rid of it, to get a gas range. After window shopping, she agreed to buy a gas range on time payments, to be paid from her job at Cronks. There was a big scene in the kitchen. My father was furious, insisting that the stove be returned to the store. Mr. Wilson, proprietor of Skelgas – which sold bottled gas and stoves – was being accused of various things by my father. Mr. Amsbury, the Minister of the RLDS church, appeared on the scene, probably called by my mother, trying to calm the waters. My mother did not return the stove. Arguments and recriminations continued that year. Mr. Amsbury tried to mediate several times. At last, apparently as a concession to save their marriage, my mother quit working at Cronks. If the waters were calmed, it was the calm before the storm. In the summer of 1951, when I was 10 years old, between 4th and 5th grades, my mother started to work at Cronks again. Her work shift was 5 PM to 3 AM. My father was furious when he realized she was working again. He went to the house of Tom Shaddy, owner of Cronk’s, demanding that he not employ my mother. When my mother arrived home at 3 AM she knew that my father was on the rampage, so she locked the door from the inside and left her key in it, so that his key could not open the door. When he began kicking the door, my mother called the police and hid behind clothes in the closet. With his kicking, the key fell from the lock and my father was able to get into the house, but the police arrived and so did Tom Shaddy. Shaddy argued with my father, saying that he had to eat onion sandwiches when he was growing up – one of my sisters says they were trying to “out poormouth each other.” If the intent was to calm my father, it did not work. My mother was afraid, so the police arrested my father, putting him in jail for the night. The next morning he was released from jail, came home, lay down on their bed, and wept. 24 © 2020 James Edward Hansen. All Rights Reserved. My mother filed for divorce. My father would not accept, so a trial was held in December. The judge, in his Decree, made several statements revealing his opinion about the role of women, for example: “It is natural that a man, traditionally the supporter of the family, should be displeased and chagrined at the wife’s doing what he should do.”15 The judge did not find evidence of physical harm. “Plaintiff complains defendant once kicked her and injured her back. Her evidence upon this claim is very weak.” Also “Plaintiff complains she feared defendant intended to do her harm because he once demanded that she produce the family rifle which she had hidden. It appears that when it was produced he loaded it and hung it over the door in the place where it was usually kept. There is no evidence that he said anything, or did anything else, to indicate that he expected to use the rifle. He says it was always kept loaded. She says it had not been kept loaded recently. The court is convinced that plaintiff is exhibiting a synthetic fear, built up through a desire to attribute fault to her husband.” The judge concluded that “It is clear that the plaintiff wife did not react to her husband with understanding, with tolerance for his viewpoint or with love for him. In the family life, at least recently, and at the trial, she showed by her actions and by what she said that she intends to do as she wishes and insists that the husband make complete concessions and adapt his thoughts and the governing of the family life to what plaintiff wants to do.” The judge ruled for our father. Divorce was denied. Arguments and recriminations continued. My father’s greatest anger was expressed as slurs against Mr. Shaddy. When my mother began to smoke, it was a new source of anger. My mother refiled for divorce and in 1954 the divorce was granted. My father got a one-room apartment on Main Street. I never went to see him. My older sisters spent limited time at home and by the summer of 1953 the three oldest were married and living elsewhere. Our family life then, with mother and only four children, was very different than the crowded, raucous family of nine. Our mother worked from 5 PM until 3 AM or later six days a week. We each had our own lives, with the children following four very different paths. We seven children saw different slices of our parents’ lives, even though the slices overlapped. Our oldest sister, Donna, gives a balanced view of our parents’ faults and strengths; our father was her hero during her 14 years on the farm. Another sister says, yes, he was a ‘male chauvinist pig’, but we should judge him in the time he lived. Maybe so. We do not tear down George Washington’s statue because he had slaves; he was living in a different world. I probably had the worst view of our father, because I was at a vulnerable age when a changing world brought out his worst. Early in high school I saw a western on television that ended with the cowboy philosopher saying “There is so much good in the worst of us, and so much bad in the best of us, that it ill behooves any of us to criticize the rest of us.”

25 © 2020 James Edward Hansen. All Rights Reserved.

Sixth grade class photo – Sam and James in lower left Chapter 4b. Denison’s Public School

Denison had an excellent public school, in which equal opportunity was reality. It did not matter that our family’s economic status was near the low end of the range or that most houses were bigger than ours. In school it was not obvious where kids were from. Everyone was treated more or less the same. My older sisters took advantage of opportunities in the Denison school and did well. In contrast, I made poor choices that retarded my academic, social and physical development. The best years for me were kindergarten and 1st grade. In kindergarten we each had to supply our own little rug to take a nap on. At recess there were see-saws, a slide, a merry-go-round, and a jungle gym (but I never climbed above the first rung). The first grade teacher, Miss Malone, was crabby. There are 32 kids in my first grade class, so maybe that is why. She rapped our knuckles with a ruler if we did something bad. Steve J. and I walked home together, about half a mile, in kindergarten and 1st grade. My mother usually gave me a nickel to buy a drink, so we would stop at a soda fountain, Candy Kitchen or Denison Drug, order a Cherry Coke or a Green River, put in our straws, and share the drink. Parents did not worry about kids walking home, and we were in no hurry. I picked up Popsicle sticks, which I collected. Sometimes we stopped at a pond beside the Dodge/Plymouth dealer, across the street from the firehouse. The pond had frogs and tadpoles, and maybe fish. Recently I learned that the pond, a bit below street level, was in the remnants of the basement of the German Veterans Bruderschaft Hall that burned during World War I, probably not by accident.16 After first grade our class was divided by the first initial of last name into two separate classes; A-H and I-Z. By the time the classes came back together in high school, I was asocial and avoided contact with Steve J., who was then class president and captain of the football team. 26 © 2020 James Edward Hansen. All Rights Reserved. In the sixth grade class photo, when I was 11 years old, I am sitting next to Sam D. Sam had just moved to town. He was one of the smartest kids I ever knew. Sam tried to befriend me. Maybe that was because in the ‘Iowa tests,’ which were used nationally, I got the highest scores in mathematics and science in our A-H class and he got the highest scores in all other areas. Sam once walked with me on my paper route all the way to my home, where he sat down and talked with my mother. He was very polite, calling her “Mrs. Poncho.” (Sam was supposed to be Cisco Kid and I was his silent partner, Poncho.) She was amazed by this kid who could talk up a blue streak. He asked if I could stay overnight at his house, which she agreed. We went to a Boy’s Club meeting that his father ran. I didn’t interest me and I never attended again. You can see the difference between Sam and me in our faces. Sam was bright and enthusiastic. He knew about political issues and historical events. He knew music. He could hear a song and say “that song was stolen” by one country artist from another, but he also knew classical music. Sam read books and magazines. His father, who I think was half Native American, had gone to college – it might have been Oklahoma State – where he was a good baseball player. He hit ground balls to us once, but Sam was not very interested in playing sports. Once Sam said to me “do you know err is pronounced urr, so if a player misses a ball it should be an urr-urr, not an air-urr”. He was making fun of a ridiculous pronunciation. He seemed to think about everything. When Sam said something it came in my ears, registered in my brain, and I remembered it, but I did not think about it or respond or ask questions. I should have been inspired by Sam to think more and read more, but I was not. Sam became exasperated with me once and criticized me for being so placid, but instead of taking it as constructive criticism, I let it hurt my feelings. Maybe my failure to emulate Sam was because the gap between us was too great. The Hansen family pre-K education system did not work for me. Karen took me to the library a few times. The first time it was to the children’s section, showing me Dr. Suess books. I thought they were weird and I wanted nothing to do with them. Years later she showed me books she was reading, Nancy Drew mystery novels. By the third one I was bored. When I left Denison at age 18 my total reading from the Carnegie library was two and a half Nancy Drew mysteries. I did read about sports. In 1950, when I was nine, I saw a baseball magazine in the Candy Kitchen with a glossy cover photo of 18-year-old Mickey Mantle of the class C Joplin Miners. It was expensive, but I coughed up some of my hard-earned paper route money to buy it. Mantle went to spring training with the New York Yankees in 1951 and made the team, although he was sent down to the Yankees top minor league farm team, the Kansas City Blues, for about 40 games. I could get the Kansas City games on the radio. I became a Yankee baseball fan and began cutting out Yankee box scores from the Omaha paper and calculating statistics. My social development was wanting. Sam and I went to a movie at the Ritz. An actor had a pamphlet in his back pocket. The camera zoomed in on the pamphlet and the audience laughed. I asked Sam what the words were. He looked at me and said “you can’t read that! You need to go see the nurse!” I did. I had to get quite thick glasses, which exacerbated my shyness. By seventh grade we started to get interested in girls. Sam was explicit about the parts of their bodies he was engrossed with. He was not attracted to their butts, he said, because “we had the same thing.” Sam was gregarious and could easily talk with girls. Once, in the home of a girl about two years older than we were, Sam was talking with her when she went into her room to

27 © 2020 James Edward Hansen. All Rights Reserved.

Left: our dog skeeter, James (age 14), brother Lloyd (age 9). Right: James (age 18) change from a shirt into a sweater. She noted the inconvenience of her boobs as she pulled the sweater on. Of course she was wearing a bra, but Sam was beside himself when he told me about it. I did not think girls were interested in me and I was too shy, so Sam and I gradually parted company. He moved away from Denison the next year.

Steve J. could have been was a role model for physical development. Once as I walked past his house he was climbing a rope hanging from a tree. He advised me to do that, which he said was useful to strengthen his body. But I was very passive, ignored the role model, and did nothing to develop physically. By high school, Steve was a lean 175 pounds and became the center of the football team. I was almost Steve’s height, having grown to five foot 10 or 11 inches by the time I graduated from high school, but I weighed only 130 pounds and was soft. It was not that I didn’t like sports. I played baseball and basketball in junior high school, but with limited success. In baseball I could field flawlessly at second base, but with 90-foot bases I was hardly strong enough to hit the ball out of the infield. A new kid, Gary Z. had moved to town. He was good, clearly one of the best two players at our age level. But he was also a smart aleck, always joking, and his baseball ‘chatter’ in the field was sometimes biting. He also thought that he was a better coach than Coach Potratz, and he thought that I should not be the starting second baseman. Once when I could not reach a ball hit up the middle he said, “see, no range!” When I came to bat during a simulated game, with Coach Potratz pitching and Gary playing centerfield, Gary came in very shallow behind second base. Coach Potratz said, “what are you doing Gary?” Gary did not move. Coach Potratz pitched, maybe an intentional fat pitch, and I hit it as hard as I could, a fly ball to straightaway centerfield. Gary bolted back, sputtering, and I ran hard, thinking I had at least a triple. I am sure Coach Potratz was smiling. However, Gary caught the ball over his shoulder. He had made his point. At least he was quiet for a while.

28 © 2020 James Edward Hansen. All Rights Reserved. I put up a basketball hoop in our backyard and practiced shooting with nobody guarding me. Coach Potratz had a free-throw shooting competition the day before each game. The winner got to be game captain. I was captain five times out of our ten games. I was a clueless captain. I just went out on the floor with the other team’s captain before the game and listened to the referee’s instructions, but it meant that I was a starter. As soon as I made one basket they guarded me tight and that was it. Four points was the maximum that I ever scored in a game. These limited social interactions in junior high, via sports, disappeared in high school. When I went to a football game I avoided going into the stands where I would need to interact with classmates and instead would go under the grandstand behind the players bench, despite limited field view. My entertainment was to go to a pool hall in the evening, but not the pool hall on Broadway frequented by most high school guys, instead the Uptown Club, a smoke-filled bar frequented by farmers, with the jukebox often booming with the deep voice of Johnny Cash. One or both of brothers Ernie and Larry S. were usually there, and I liked to play against them. They were big muscular guys, and very good pool players. Usually it was snooker. Snooker is played on a big table – bigger than a pool table – with small pockets, so the game takes longer than pool. Snooker was 35 cents a game, compared to 10 cents for pool. I was not as good as Ernie or Larry, so I tried to negotiate a spot before a game of snooker. The only thing at stake was that loser pays for the game, but that was enough incentive for keen competition.

The best thing that I did in school was to decide to save money for college. The college idea came up when I was in the 5th grade. Eleanor was in the 12th grade. She had taken stenography and was able to do shorthand and type at phenomenal rates that seemed physically impossible, keys flying and yet not getting stuck. Eleanor was hired to work for the Principal, coming in very early before school started. One day she came home with the information that I had tied some guy in high school for the highest IQ in school. That guy was known as a brain, so I concluded that I could probably be successful in college. Inexplicably, I did not seem to realize that I had better become more involved academically. My academic achievements in Denison were limited to mere hints of potential. Once in grade school a teacher was puzzled by the phrasing of a question in the mathematics book “20 times 20 is 400 so what is 19 times 19?” I said instantly “it’s 361, they want you to subtract 20 and 19 from 400.” I saw that without going through the logic, which is: subtract one 20 to get nineteen 20s, which is the same as twenty 19s. Then subtract one 19 to get nineteen 19s. In high school I took . In the first week, Mr. Heinzelman gave us an exam to see what we were starting with. I got minus 3, while the next best score was minus 19. Mr. Heinzelman said he was only giving one “A,” because there should not be that large a gap. Nobody was annoyed at me – in that era kids were not under pressure, life was easier. So I knew that I had potential, but I did nothing to develop scientific talent. I did not come in for lab work or extra activity. I had the excuse that I needed to take papers to Denison businesses in the morning and after school divide up papers for the newsboys and newsgirls; but still – what was I thinking? I graduated 23rd in a class of 93 students, the last person in the upper quarter. I did not realize how lucky I was until I received a letter of acceptance for admission to the University of Iowa. The University waived tuition, because I had high college entrance test scores and was in the top quarter of my class. In-state tuition was $440 per year when I was a freshman, so if I had been 24th, instead of 23rd, I would have run out of money by my second year of college. 29 © 2020 James Edward Hansen. All Rights Reserved. We will return to Denison, Iowa, in the final chapter. Denison is America, if not the world. Bill Nye says that every scientist is already a scientist by grade school. That was not true in my case. I would have to struggle to catch up, if that were possible at all. And there would be a price to pay. The delinquent risks falling behind, being too slow, missing opportunities.

Becoming a scientist is not simple. You don’t go to school, get filled up with education, and come out a scientist. The best that can happen is that you get pointed in the right direction. Becoming a scientist is a process, not easy to explain. I will try, by relating my experiences. I had unusual opportunities, even if I did not recognize how remarkable my situation was. I took my first step as a result of a peculiar requirement imposed by Professor James Van Allen.

30 © 2020 James Edward Hansen. All Rights Reserved.

James Van Allen discussing Earth’s radiation belts.

Chapter 5. University of Iowa

My mother gave me a ride to Iowa City. Actually, I did the driving, about 200 miles east on Highway 30, which was two undivided lanes, one in each direction. Truck traffic and hills required vigilant passing. We talked little. I was anxious, moving to a different world. We found Hillcrest dormitory. I picked up the room key, carried up my box of clothes and came back to the car. Mom wanted to leave this foreign place. She did not want to see my room, just get back on the road home. I took her box of cookies. Her last words were “be sure to write.” I knew that I had social deficiencies, in addition to academic and financial challenges, but I made little effort at social improvement. My roommate, Bob, was a nice guy, but I did not want to socialize. Luckily, he befriended a guy across the hall. Once that fellow joked at me – I slapped him defiantly, knocking his glasses off. They decided that I was strange, and left me alone. Room and board the first year, $1000, depleted more than half of the money I had saved over 10 years. At the end of my freshman year I found a $25 per month room, on the 2nd floor of a house at 409 Iowa Avenue, where I would spend my remaining years in Iowa City I was lucky to find a summer job that partially restored my bank account. Reitzel Pipeline Construction was putting gas pipelines into Denison. I only had to measure the length of pipe installed each day at the multiple locations of digging. Back to Iowa City in the fall: I wanted to minimize costs, so that I would not need to work in the library shelving books, which I did as a freshman. Dinner was a TV dinner heated on a hot plate. Breakfast and lunch were cereal and milk, with some fruit and vegetables. My ‘refrigerator’ was the space between the window and screen. My mother sent a shoebox of cookies and homemade candy every six weeks or so. So I began getting heavier from afternoon snacks.

Midway through my undergraduate years I made a serious mistake. While shopping at the grocery store, I put a tube of toothpaste in my pocket rather than in the shopping cart, the store owner saw it, and I was arrested for shoplifting. That mistake could have erased all my hard work – my grades were nearly straight A. When the judge saw my academic record and the fact that I had no prior offenses, he put off sentencing. It appeared that, if the store owner agreed, he likely would drop the charges. 31 © 2020 James Edward Hansen. All Rights Reserved. However, I called the judge and told him that I had done a similar thing a few times before. He got angry, suggested that I must be trying to get thrown out of school, and ordered me to see a university psychiatrist. In reality, I only had qualms about not being honest when I knew that he was trying to help. Eventually the charges were dropped, and my official record was clean. Why tell that story? It is easy to be too hard on yourself. Everybody makes mistakes. It’s important not to give up on yourself, when you make a mistake. I made a lot of mistakes. Usually mistakes can be overcome. However, you had better minimize them. There is another reason for the story. What if I had not been white? Would that mistake have been eliminated from my record? Perhaps the justice system is color blind in Iowa City today? I’m not sure, but what about elsewhere? Laws alone do not assure equal opportunity.

Professor Satoshi Matsushima was head of the Astronomy program in the Department of Physics and Astronomy. Matsushima was hardly five feet tall and perhaps 100 pounds. He was energetic in his Astronomy course lectures, but did not always have great command of all the astronomical concepts or geometry. That was o.k.; the course had a good text book. Andy Lacis and I walked in the same direction after Matsushima’s class. We even talked, which was the most extensive relationship that I had as an undergraduate. Andy had a short flat-topped haircut that made him look like a young Roger Maris, the Yankee’s all-star right-fielder. Andy was of Latvian origin – his family escaped from the USSR at the end of World War II and lived in a refugee camp in Germany until emigrating to the United States. Andy and I dubbed Matsushima the “coach” (if we intended it as a term of endearment, that would change during later battles). At least we were gaining some self-confidence. Physics was hard. I avoided taking any course taught by Prof. James Van Allen, Department Chairman and discoverer of Earth’s radiation belts,17 because I did not want him to know how ignorant I was. I still felt that way as a senior about to graduate Summa Cum Laude (‘with highest distinction’) with a double major in physics and mathematics. That academic record indicated only that I had worked hard. For sure, I was not yet a scientist. Prof. Matsushima gave Andy and me a push in the direction of becoming scientists. He identified us as the best students in his astronomy class and tried to persuade us to go to graduate school at Iowa. He gave us part-time, paying, jobs, doing astronomical calculations.

Matsushima also made a clever suggestion that altered my career path and my life. He suggested that Andy and I take the Ph.D. qualifying exam as seniors. This exam was taken by physics students after a year of graduate study, unless they deferred it. The exam could be taken a maximum of two times. If passed, the student could enter a research path aimed at a Ph.D., with additional checkpoints at which the student’s program might be terminated short of a Ph.D. Matsushima said the exam would be good experience and help us pass the next year. In fact, we both passed easily, the first undergraduates to pass the Ph. D. qualifying exam. Passing score was about 90. Andy’s score, about 100, would have been higher, but he decided not to take the second day of the two-day exam – it was enough experience, he said, and really hard. Matsushima noticed Andy, and, like a little general, he hustled Andy into the exam, albeit hours after it started. I passed the exam, with a score of one hundred and something in the teens.

32 © 2020 James Edward Hansen. All Rights Reserved.

Mount Agung on Bali, erupting in 2017 As a result Van Allen noticed me. I was lucky. I should give the coach some credit. It is a bad idea to be a wallflower -- there were about 50 graduate students in physics. It is better to ask a question now and then, but be sure they are not foolish questions. Later, when I was in graduate school, Van Allen suggested a research problem to me: why did Venus emit so much microwave radiation? He also appointed himself to be on my thesis committee. The latter action turned out to make all the difference. Matsushima’s motive, in pushing us to take the exam, was to show Van Allen that he had top students. Van Allen agreed that the Department should offer both Andy and me NASA traineeships. No more need to shelve books or shovel chicken manure (which I did one summer). The traineeships paid our graduate school expenses and provided a $200 per month stipend. Presidents Eisenhower and Kennedy, as well as Congress, supported brainpower development to address the space challenge. It was an approach unlike that of today’s government, which, despite merits of improving national infrastructure and economic competitiveness in science and engineering of clean energy, does not offer analogous support for the current climate challenge.

As Andy and I bent over the exam table, puzzling over knotty physics problems, a global scientific experiment began to play out over our heads. On 17 March 1963, Mount Agung, on the island of Bali in Indonesia, exploded. Lava flows from the eruption had a local effect, killing more than 1000 Indonesians; however, massive amounts of gas and dust were blasted into the atmosphere, reaching heights of more than 10 miles, where stratospheric winds spread them all around the world. Blissfully ignorant of this activity overhead, we began our graduate studies. Andy and I each intended to first get Master’s degrees in astronomy before pursuing a Ph.D. in , which was broadly defined to include anything from astrophysics to planetary science. Once again, Prof. Matsushima had a fruitful idea. He suggested that we observe the lunar eclipse that would occur on 30 December 1963. His suggestion was spurred by the need to make use of the Astronomy section’s small telescope, which was his responsibility. On the 29th of December, Andy and I swept leaves, cobwebs and mice out of the little domed observatory on a hill in a cornfield just outside Iowa City. We were novice astronomers, but, fortunately, a longtime graduate student, John Zink, could help operate the telescope. We were to attach a photometer to measure moonlight, sunlight reflected by the moon, at several wavelengths – in other words, measure the brightness of red light, blue light, and so on.

33 © 2020 James Edward Hansen. All Rights Reserved. We met with Zink in the physics building to plan the observations. Prof. Van Allen happened by as we were talking. Zink used this as a chance to ask Van Allen for a reference letter. With a big smile, Van Allen said “Sure, I will tell them you came to Iowa as a very promising student and just petered out over time,” as he made a wiggly downward motion with one hand. Zink’s smile was uncomfortable, because he had been a student a long time. However, Van Allen’s good nature was so obvious that we were sure he would write a good letter. Given Van Allen’s always pleasant, pipe-smoking, demeanor, I should have been comfortable talking with him. The problem was that I worried about my weak points. What if he asked me about the functioning of the photometer: a basic instrument, but a foreign contraption to me?

December 30 had the coldest night of the year. An Alberta Clipper poured Arctic air into the Midwest from western Canada. It was 15 degrees below zero Fahrenheit, 26 degrees below zero Celsius. Zink did the observations. There was no point to fool around teaching new kids on that night! We handed him what he needed, held his gloves if he had to take them off, and warmed the car up for him, so that we could take a break once during the observations. We were surprised as the moon moved into Earth’s shadow. It disappeared entirely! Just black sky, where the moon had been. The moon in eclipse is usually visible, because some sunlight is refracted (bent) by Earth’s atmosphere or scattered by molecules or particles into the shadow. It took little thinking to realize that something in Earth’s atmosphere was blocking the sunlight that normally gets passed into Earth’s shadow. The obvious candidate was stuff dumped into the atmosphere by the Mount Agung volcanic eruption. I jumped on this problem, quickly reading scientific papers, to stake out the topic for my Master’s thesis in Astronomy. A Czech astronomer, Frantisek Link, had worked out the eclipse geometry, describing how light rays are refracted and scattered into Earth’s shadow. Once I understood Link’s equations, I had to write a computer program to calculate the brightness in the shadow. Then I could try a range of assumptions for the amount and distribution of volcanic aerosols in the atmosphere. I spent weeks translating and studying Prof. Link’s book in German,18 until I realized he had published almost the same thing in English in Advances in Astronomy and Astrophysics! In the end, I could estimate the aerosol amount in Earth’s stratosphere in December 1963. I also concluded that similarly useful lunar eclipses, ones when the moon passes close to the center of Earth’s shadow, occur about once per year. Such aerosol information is valuable, because volcanic aerosols are a potential cause of climate variability. I wrote a paper19 based on this research and got it published. Van Allen’s policy was that a paper published in a peer-reviewed journal constituted a Master’s degree thesis. Therefore, I was free to get on with Ph. D. research. Still I was not yet a scientist. Technical ability is only a prerequisite; even a Ph.D. behind your name does not make you a scientist. Van Allen used a curious ‘original proposition’ method to help instill unbiased scientific objectivity, as I describe later. However, the making of a scientist is like learning from a Jedi master: it requires years of practice, and there is no guarantee that you will acquire the Force and be capable of carrying out fruitful, unbiased scientific studies. Here is a point for an interjection: a commentary on the sad state of my physical condition. It began with a letter from my sister Lois. She had seen a photo in a local newspaper of me looking through the telescope at the lunar eclipse. 34 © 2020 James Edward Hansen. All Rights Reserved. “Is that the moon looking through a telescope?” My round face was the object of her jest. I weighed 130 pounds as a freshman, but a sedentary life and snacking made me round. The moon observing the moon in December 1963 was out of shape and weighed about 175 pounds. It was getting to be time to face the real world! When I entered college I did not know quite what it would be like to come out the other end, but I liked to imagine that when I finished college I could have a beautiful girl friend. That was certainly a reason to get in shape; but I had another reason. I responded to Lois’ goading: “just wait a few years, I’ll show you!” This sparked her interest; her return letter asked: “Oh, what are you going to do?” I did not answer. My goal, to become an astronaut, would seem outlandish, given my physical appearance, shyness, and near-sightedness. While a college freshman, I did as many weakling American boys had done: I responded to one of the ubiquitous Charles Atlas advertisements. Atlas got sand kicked in his eyes by a bully on the beach, and then made himself into a muscle man. I was too busy with classwork, though, so I put the Atlas lessons in a drawer. Once a graduate student, I started doing the exercise Atlas said was most important. It is high cardio, focused on the pectoral and shoulder muscles, and takes 3 minutes. It was not smart to do a single exercise, but it put me in decent shape at 160 pounds. Later I will suggest a high-cardio 3-minute exercise for the largest muscles – thighs, buttocks, and the muscles supporting the body core, followed, after 4 minutes to catch your breath, by a 3- minute high-cardio modification of the Atlas exercise. If you are in your 20s, in 10 minutes a day it is easy to shape your body to its optimum, and then keep that body shape your entire life, if you have a healthy diet. I will come back to this later and be more explicit. It is important. It helps make you an optimistic person, one who will get up after being knocked down.

Prof. Van Allen defined a specific rite of passage for Ph.D. candidates. Each candidate had to offer an ‘original proposition’ and defend it before a committee of five professors. Ideas outside conventional wisdom were encouraged. We had to describe a plan for how we would evaluate the proposition. The plan had better not expose ignorance of sound physics. Van Allen perhaps knew I was interested in planets, because, for Matsushima’s Astrophysics class, I chose the atmosphere of Jupiter as my discussion topic. In any case, Van Allen told me about observations of high microwave radiation from Venus. He wondered whether this radiation was an indication that Venus had radiation belts analogous to the large, donut-shaped regions of energetic charged particles that swaddle Earth.17 I read the published papers, hoping to get an idea for an ‘original proposition’ about Venus. Venus permitted a wide range of speculations, because the entire planet was blanketed by pale lemon-yellow clouds that prevented observation of the planetary surface.

Carl Sagan, an Assistant Professor at Harvard, and Jim Pollack, a post-doc with him, argued that the high microwave radiation was from a very hot planetary surface, kept hot by a strong ‘greenhouse’ effect. They believed that the Venus clouds were water ice, like cirrus clouds on Earth, which scattered sunlight to the ground, while the atmosphere contained water vapor and carbon dioxide that absorbed outgoing heat radiation. The Venus surface was thus kept warm,

35 © 2020 James Edward Hansen. All Rights Reserved. somewhat analogous to the way sunlight warms the air in an automobile with closed windows – or in a greenhouse.20 Ernst Opik, an Estonian astronomer working at Armagh Observatory in Ireland, had a different idea, based partly on the color of Venus. He thought the clouds were desert dust suspended in the air by a continuous dust and sandstorm. He assumed that sunlight provided energy for the storms, which dissipated their kinetic energy into heat, thus warming the planetary surface. To devise an original proposition, I had to first understand the weak and strong points of existing interpretations. I needed to find reasons to be skeptical about these existing interpretations. One reason to doubt the Sagan and Pollack model for Venus was that the pale lemon color of Venus does not resemble water clouds. Perhaps the color of Venus could be explained easier with Opik’s model of a dry, dusty atmosphere. However, Opik’s model required continual storms to keep large dust particles in the air, which seemed a dubious assumption. My proposition was related to Opik’s model. The novel aspect was that the energy source was the interior of Venus, with this interior heat being trapped by micron-sized dust that could be kept aloft by slight breezes. For the sake of keeping the proposition plausible, I assumed only that the internal energy source on Venus was similar in magnitude to that on Earth. There is a continual energy flow from Earth’s interior to the surface of about one-tenth of a watt per square meter.21 This energy comes from two sources: primordial heat left over from formation of Earth and radioactive decay of elements in Earth’s mantle and crust.

Van Allen was the chair of the committee hearing my ‘original proposition.’ I spent time critiquing the other hypotheses for the high temperature of Venus, described the dust/insulation model, and discussed some ideas about how I might investigate the matter further. The committee was satisfied. If the dust/insulation model had low probability of being reality on Venus, that was not a problem. In one sense, low probability of a proposition increased its merits as a learning tool, because it forced me to be skeptical of my proposed interpretation. I got to pursue this research in Japan. Prof. Matsushima received a grant to spend a year at the Universities of Kyoto and Tokyo. Matsushima did not want to risk losing his students to another professor, and Andy and I liked the idea of spending a year in such an exotic place.

Before going to Japan, I fixed two things that had long bothered me. I could afford some luxuries, as the $200/month from NASA exceeded my living expense for a $25/month room. First, I wanted to ditch my thick glasses. Mainly I wanted to be more attractive to girls, but also it might help my case to be an astronaut. Years later, I had the lenses in my eyes extracted and replaced with lenses that provided excellent vision for both reading and distance. However, that technology was not yet available in 1965, so I got contact lenses Second, I wanted to fix my crooked front teeth. An orthodontist told me it would take two years. Dejected, I called a professor in the College of Dentistry. He suggested that I consider capping the teeth, and he recommended an Iowa City dentist. Dr. Gingerich looked at the four crooked front teeth, each with a discolored filling, and said that, of course, they should have permanent caps. In one week, days before leaving to Japan, a forever problem was finally fixed. Unfortunately, these actions addressed only my superficial deficiencies. 36 © 2020 James Edward Hansen. All Rights Reserved. Chapter 6. Exotic Japan Kyoto, in the fall and winter of 1965, exposed more of Prof. Matsushima’s students than one of them should care to admit. Andy and I entered a different world in Japan. Kyoto was of Japan for 1000 years, until the imperial family moved to Tokyo in the 1800s. Temples and gardens of Kyoto are revered by the Japanese as the center of traditional culture and Buddhism. Andy paid more attention to the cultural opportunity, and he studied the difficult language, so he could interact with the people. I didn’t think much about those things, and I relied mainly on Andy to find our way around. The International Student House was a newish two-story building on a hill in a Kyoto suburb. From there we walked on a narrow street that wound down the hill, houses so close to the path that Japanese voices spilled into the street. A broad street at the bottom of the hill had a trolley to Kyoto. People pretended not to stare – Westerners were scarce in Kyoto then. Changing to a second trolley in Kyoto, we got to the edge of the Kyoto University campus. There a broad road and path skirted the outfield of a baseball diamond, where an outfielder was shagging flyballs. The Institute for Astrophysics, our destination, was an old building with darkened windows. We understood why later, when on a cool winter day, during a lecture, a student got up, put coal in the stove, and stoked it noisily. Japan was still a developing country in 1965. Andy and I followed Prof. Matsushima into the office of Prof. Sueo Ueno, the esteemed senior scientist of the Institute for Astrophysics. Prof. Ueno, a pale, thin man, smiled and bowed deeply, a Japanese tradition. We were just students, but guests. We bent awkwardly in return. It did not matter. Prof. Ueno eagerly showed us his papers. They were full of long equations describing transfer of radiation through a medium. The radiation could be sunlight, or heat, or neutrons, and the medium might be a cloud, the ocean, interstellar space, or a nuclear reactor. Prof. Ueno’s ‘invariant imbedding’ equations had a sterling pedigree, originating with V. Ambartsumian and developed further by the genius S. Chandrasekhar, both giants in the field of astrophysics. Ueno showed us a paper on such-and-such, and asked: “might you be interested?” His politeness to lowly students demanded a “yes,” but I could say it honestly, because I wanted to do calculations for Venus. Prof. Ueno smiled happily as we left his office. I had a pile of his papers. Most of these papers were probably not relevant to my plans, but I hoped to use Ueno’s invariant imbedding method to calculate how the brightness of Venus changes across the face of the planet. Venus, observed through a telescope, is a bright, pale lemon-yellow ball, but its brightness is not uniform over the face of the planet. Venus is less bright toward its edge, called the “limb” of the planet; this dimming is called “limb-darkening.” My idea was to calculate limb-darkening for different models of the Venus atmosphere using Ueno’s invariant imbedding method. One model would be for a dusty atmosphere. Another would have water-ice clouds, similar to cirrus clouds, as suggested by Sagan and Pollack. Then I could check which model agreed better with observations of Venus. I struggled for weeks, writing computer programs. Luckily, Kyoto University had just acquired an IBM computer that used punched cards, rather than the earlier punched paper tape. That meant, when I found a mistake in my program, I could usually fix it by replacing one card. 37 © 2020 James Edward Hansen. All Rights Reserved. The merit of Ueno’s numerical invariant imbedding method was that it could incorporate realistic scattering particles. Dust and cirrus ice crystals scatter light in different directional patterns, and dust absorbs part of the sunlight that hits it, while cirrus particles scatter it all. After months of work, I showed that limb-darkening was different for ice and dust. However, Venus observations had a substantial “error bar” or uncertainty, especially in data near the planet’s limb. Either dust or ice clouds could fit the observations within the error bars. I was forced to conclude that better observations were needed. I had not learned much, but I could use it for one chapter in my Ph. D. thesis.

Meanwhile, a package from Carl Sagan arrived. I had written a letter to Sagan describing my “original proposition” and asking for one of his “in press” papers (a paper that had passed peer review, but the scientific journal had not yet been published). Sagan sent much more than I requested – a 2-page letter and several papers by him and Jim Pollack. Pollack was his post-doc, a recent Ph.D. graduate. Carl explained why he thought that my dust model could not be correct, and why his (and Jim Pollack’s) interpretation of a strong greenhouse effect with carbon dioxide, water vapor and ice clouds was a more likely model. Sagan went to a lot of trouble to respond to a letter from a student he did not know. Biographers of Sagan paint a mixed picture of him as a person. Our interactions included cases where we had differences of opinion, but in every case, he was understanding and generous. I liked him a lot.

A NASA poster appeared on the bulletin board at the Institute for Astrophysics and struck me with wonder. It was an advertisement for post-doctoral positions at NASA Centers in the United States. Could this change -- from fantasy to plausibility – my hope to be an astronaut? One paragraph described the Goddard Institute for Space Studies in New York: “The Institute for Space Studies conducts theoretical research in … the physics of planetary bodies and their atmospheres. The program includes basic studies in meteorology and theories of turbulence, convection and radiative transfer.” It was the very research that I hoped to get into more deeply! I sent a letter to Prof. Van Allen on 10 February requesting that he write one of the four reference letters required by NASA. I said that I thought I could finish my Ph.D. thesis by August. Prof. Van Allen, in his return letter, dated 15 February 1966, said he was pleased that my thesis work was going well, but an August degree seemed impractical. The thesis would be due by early July, and Prof. Matsushima would not return from Japan until September. He said that my defense could be arranged in early autumn. He sent a cc of his letter to Prof. Matsushima.

An explosion ensued on the top floor of the Institute for Astrophysics. I was summoned to Prof. Matsushima’s office. He was standing. His face was red. His first words were “you are not my friend!” He held in one hand the letter from Van Allen. Friction between graduate students and advisers is not uncommon. In principle, the student- professor relation is mutually beneficial. Students need guidance, and a professor may have limited time for research and limited skills in developing areas such as computer programming. Conflict can occur with publications. If you ask the professor and student their contribution to a paper, the sum often will exceed 100 percent.

38 © 2020 James Edward Hansen. All Rights Reserved. Matsushima was appropriately a co-author on our paper interpreting the lunar eclipse after the Mount Agung eruption. He suggested the observations and obtained Link’s book in German. I did the research on my own and wrote the first draft of the paper. But how much does the student owe the professor? The problem here was the length of indentured service. I wanted to escape after three years in graduate school, while Matsushima expected a longer period of research and mutual writing of papers.

NASA required four reference letters. One had to be from the Ph.D. adviser. If I went to Matsushima first, there was zero chance that he would approve of the application. So I first sent requests to three other people, including Van Allen. I aimed to get the process started before Matsushima could stop it. It was a tricky thing to do. Science today might be a tricky business. Certainly I thought so in my middle age, when I did not encourage my children to go into science as a career. Let’s reconsider the matter later. I suspect that Prof. Van Allen understood my situation. His letter ended: “However, we can arrange an examination in early autumn at a mutually agreeable time. Meanwhile, I see no reason why you should not apply for a post-doctoral fellowship, stating your exact situation. I have forwarded your application to NRC/NAS.”22 Prof. Van Allen had done exactly what I needed! No wonder Matsushima’s face looked as if blood vessels were about to burst. Van Allen’s letter was more important than his. Besides, if he refused to write a letter, it would look bad to Van Allen, and Matsushima did not yet have tenure. Still, in Prof. Matsushima’s view, I had committed a grave sin.

Meanwhile, at age almost 25, I had my first girlfriend. This story is more embarrassing than my shoplifting episode. There is little to be learned from it, so I may cut it before publication. I spent a lot of time in the library. The librarian was a Japanese girl, about my age. I’ll call her Kamana. Her English was good. Our communication problem was my extreme shyness. Luckily the 1960s were a different era. Human-to-human contact was not fraught as it is today. Once, in checking out books, our hands touched accidentally. When it happened a second time, I wondered if it was accidental, and I started thinking about her. She was attractive, but I had never asked a girl for a date. The matter was solved a week later, when I couldn’t find a book in the shelves. This time when our hands touched I was in tune with her. I even looked in her eyes without averting my gaze. There is nothing as wonderful, I think, as a passionate kiss with a personable woman who is aching to be kissed, not kissed by anybody, but kissed by you. That’s not the embarrassing part. It was how to go further. It so happens that Andy and I were about to buy a car, a used mid-1950s Mazda. Mazdas are a nice car now, but in the 1950s they were pretty much a tin can. That was o.k. with us. Andy wanted the car for more convenient transportation. Andy was from the sophisticated end of Iowa, but I was from the country west. On our first date Kamana and I drove to Kyoto for dinner – and drinks. Then we went walking, holding hands, in the entertainment district, an area with ‘love hotels’ on every street. Most couples in Japan did not marry before their mid or late twenties, so there was a booming business for places where they could spend an hour or two together. These were nice, reputable places. But no one told me about them. Perhaps Kamana did not want to seem experienced.

39 © 2020 James Edward Hansen. All Rights Reserved. In any case, I did what I thought Midwestern guys did. We got in the car to drive out of the city to a private place. Unfortunately, I was slightly inebriated, and should not have been driving. I drove straight out of town on Gojo Street, some distance without incident. We got to an area with agricultural fields at a lower elevation than the street. At one intersection there was a path down to the edge of the field and under the street. We could not wait longer. I steered onto the path, but the wheels on my side slipped off the path. The car rolled over twice, shattering windows on both sides, coming to rest on its top. We were tossed about, but could open the doors to get out. The only injury was a small cut on one of Kamana’s calves. We climbed to the street, laughing at the upside down Mazda. There were soon several Japanese people, looking at our predicament. I decided to wait until morning to get assistance to recover the car. We caught a taxi. After dropping Kamana off at her home, I went back to the International House.

I will not forget the look on Andy’s face. First, for a second or two, it was a look of anger – what had this idiot done to our fine Mazda? Then he began thinking. I suggested that we find a vehicle repair place with the capability to lift the car back to the road. It would be a big challenge for Andy’s budding Japanese speaking ability. Andy had a better idea. We should go first thing in the morning to Prof. Matsushima and reveal the mess. Matsushima would do everything possible to avoid a scandal in the media. He had brought his two fine students to Japan to show off, not to be made a fool of. So the next morning we were standing on the road by the rice field as a crane slowly lifted the sorry Mazda back to the road. Matsushima watched, stone-faced. He said that the neighbors standing around were saying that the young American and a Japanese girl were laughing as they crawled out of the car – they could not possibly have been sober. I supposed that they were wondering who the foolish driver was. The car still ran fine. We replaced the windows. It looked a little banged up, but it served its purposes. Andy had a young Chinese girlfriend and I went out regularly with Kamana, even learning the merits of the Kyoto entertainment district. In late February 1966, Matsushima, Andy and I had to leave Kyoto for the University of Tokyo, for the second half of our year in Japan. A few days before we left, the boy friend of Kamana’s girl friend suggested to me that Kamana was willing to go with me to Tokyo. Although a short- term commitment, the months in Tokyo, would make it more difficult to finish my thesis, it was tempting. But then what? It would create a still more difficult situation. I felt cold-hearted, but I did not want a bigger commitment. I wanted to focus on space science research, to enhance the chance of becoming an astronaut, and I still felt that I was way behind where I should have been. Mrs. Kobayashi, the manager of the International Student House, did not make it easy. Always cheerful, she arranged a party the evening before Andy and I left. She explained that Andy and I needed to be off to more adventures, and then cajoled the group to sing “You are my sunshine.”

The morning was cold and grey. Tokyo is not quite 300 miles from Kyoto. By car, with today’s roads and vehicles, it is probably less than five hours. For us, it was more than 24 hours. Our little Mazda was not meant for mountain climbing. The roads were narrow, crooked, and went through towns. Signs were in Japanese and not always clear. Day became night. We used 40 © 2020 James Edward Hansen. All Rights Reserved. the sky to check our direction. The Mazda began to vibrate. We found that one of the engine’s fan blades was bent. Andy fooled with it a few times, then broke it off. That helped for a while, but vibrations grew again. Andy broke off the opposite fan blade, for symmetry. That reduced vibrations, but the motor overheated. We had to stop and let it cool off. Night changed to day as we approached Tokyo, and the time between overheats became shorter and shorter. We chugged into Tokyo at midday and found our way to the International House. Tokyo was different. We were in Shinjuku district, a beehive, its lights rivaling Broadway. The International House seemed out of place – an old, grey building, on a side street, but even this street hardly slept. Down the street was a pachinko parlor – a cross between a slot machine and a vertical pinball machine – with scores of machines in rows. You buy a pile of chrome marbles and feed them into the pachinko machine, with little control on the ball’s destination; but at least you can’t cause a game-ending “tilt.” A ball in the correct hole, releases a bunch of marbles to your tray below. The jackpot hole yields enough marbles for a prize. It’s so noisy, you should wear earplugs. The popularity of pachinko, with even housewives playing, was puzzling. I had no time for pachinko. I read scientific papers or worked on my thesis into the wee hours. I took a walk before bed, as late as 3 AM, when there were still people on Shinjuku streets. A few times there were boys in black samurai dress, going through a ritual with long sticks or swords.

What to do for a Ph.D. thesis? I was fretting. My “original proposition” -- that the Venus clouds were fine dust that helped keep the surface warm – was a longshot. It could still make a Ph.D. thesis, as long as there was no evidence proving it to be wrong. I had better hurry up and finish. The planned to send entry probes to Venus, which would measure the composition of the air and probably take pictures. Their data would likely prove whether my interpretation based on “remote sensing” was right or wrong. Unless we travel to the planet, remote sensing is all we can do. However, the only energy that penetrates Earth’s atmosphere so that I can be measured at the ground, is in (1) radio waves and some microwaves, and (2) infrared and visible radiation, as shown by the white regions on the top bar of Figure 6.1. Remote sensing is still needed, even after entry probes directly sample the Venus atmosphere, for the sake of putting the local entry probe measurements in a global context. Also remote sensing can reveal additional information not obtained by entry probes. I could see two good ways to expand my radiation calculations to extract more information on the Venus clouds and atmosphere: (1) calculate how sunlight becomes polarized when it is reflected by Venus, (2) calculate absorption by different gases of the sunlight reflected by Venus. Never mind, for now, what those mean exactly. I realized that either one of those tasks would probably take at least two years. I was already in my third year of graduate school and had spent six years in Iowa City as a troglodyte. I wanted to finish my thesis and enter the real world. I had material for the front sections of a thesis. I reviewed all models proposed for Venus, including the ionosphere models that were Prof. Van Allen’s initial interest. Although various Ionosphere models had been suggested, I could describe discrepancies with remote sensing data for all of them. For all practical purposes, they could each be ruled out.

41 © 2020 James Edward Hansen. All Rights Reserved.

Figure 6.1. Electromagnetic spectrum (credit: NASA via Wikipedia)

The Greenhouse model of Sagan and Pollack seemed to be the most plausible of existing models, but there was something fishy about it. They assumed a large water vapor amount to explain the greenhouse warming, but observations did not reveal much water. And to explain microwave data, they needed clouds of just the right properties – or, they suggested, maybe there was dust in the air near the surface. That was ad hoc, so it was another weakness of their model. There was one more thing I could do: check whether my Dust model was consistent with microwave observations of Venus. I found that the amount of dust required to yield the atmospheric opacity implied by the microwave data was the same as the amount of dust needed to keep the planet hot by blocking heat radiation. So at least the Dust model was self-consistent. Meanwhile, I was in a contest with Prof. Matsushima. I submitted my application for a NASA post-doc position on 10 February 1966, including a list of four references. In a letter dated 23 March the NAS/NRC said that they had three reference letters, but not Matsushima’s. Prof. Matsushima said he wrote the letter, but the secretary was not good and probably lost it. He did not keep a copy. I needed a new reference form from NAS/NRC. On 2 April I requested it, but, after worrying for two weeks, on 17 April I sent a letter to NAS/NRC explaining the situation and asking if I could seek a letter from an alternative Iowa professor.? They refused to change their requirement. Then, on 23 May, they sent a letter saying that they had received the form from Matsushima. In July, the NAS/NRC sent a letter offering me the post-doc position at the NASA Goddard Institute for Space Studies! First, I was in shock – somehow I had not expected it all to work out. Then I realized that I still had a problem – I needed to write the dissertation that I was supposed to defend upon return from Japan. Another complication arose upon returning to Iowa: an announcement of a “limited number of career appointments for scientists to serve as astronauts.” Application deadline: 8 January 1967. 42 © 2020 James Edward Hansen. All Rights Reserved. I sent a letter asking if my near-sightedness disqualified me. Answer: exceptions are possible, depending on other qualifications. So I had even more pressure to finish my thesis. My thesis defense was scheduled for December. The committee was supposed to receive the thesis a few weeks before the defense, but, Prof. Matsushima said, students were often late in delivery. I gave the first half of the thesis to Matsushima and said that the second half was almost done, but he suggested changes, which he had the right to do. When I came in the next week Prof. Matsushima announced “Van is angry at you! You missed the deadline.” I had never seen Prof. Van Allen angry, so I was skeptical, but worried. Matsushima had a big smile. I felt that I had been tricked. But I knew it was my own fault; I had been too slow. I should have worked harder when I was in Japan. Fortunately, I could reschedule. Unfortunately, I accepted Matsushima’s suggestion of 23 January, the latest date allowed by the Graduate College. Van Allen’s note accepting the new date attached Matsushima’s letter requesting the change. Matsushima’s letter included a statement that he wanted to be sure that my thesis “contains the whole material to make a paper publishable in the most competent journal such as the Astrophysical Journal. As long as I stay at Iowa as a person responsible for Ph.D. degrees granted in the astronomy area, I wish to make this a criterion for judging whether a thesis is acceptable for the degree or not.” Yikes. Not only had I chosen a schedule that allowed no time for revisions if the committee found any problems, Matsushima was imposing an added requirement. I was annoyed that I had put myself in such a tight situation. I began working really hard, sleeping only 4-5 hours per night. The thesis turned out to be 278 pages, really long; how could I avoid flaws that would require revision? Even typing requirements were strict. I put off the astronaut application. I could apply in the next round, within a few years. Better to focus on my thesis and NASA research. Any success would make a future application stronger.

January 23: why was the committee taking so long? I had been sent out of the room, while they had their formal discussion of my oral defense of thesis. I had answered all questions well, I thought. Finally the door opened. Van Allen had a big smile and Matsushima was dour. I felt a rush of relief. Van Allen extended his hand, “Congratulations,” no changes in the thesis were needed. I could deposit it with the Graduate College. I would get my degree at the winter Commencement. We chatted a few minutes. Prof. Van Allen said that he hoped I would write a paper based on the thesis before leaving to New York, so that the University, not NASA, received credit. That explained why Matsushima was subdued. There was no requirement that I write a paper, only a suggestion. Matsushima no longer had any authority over me. It took a few weeks to write the paper. I took it to Matsushima’s office and asked him to submit it to the Astrophysical Journal, so the address would be the University of Iowa. He was surprised to see that he was co-author. It felt good to see him happy – bygones were bygones – and I owed him for his help getting the NASA traineeship and suggesting the lunar observations. The conflict with Prof. Matsushima had helped prepare me for later battles that would be more difficult and traumatic than those in Iowa City. But first, this pacific, innocent, young man from Iowa got to spend two years as a privileged post-doc in the marvelous world of New York City in the 1960s. 43 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 7.1. Goddard Institute for Space Studies. St. John’s Cathedral is at the end of 112th Street. Chapter 7. New York City in the 1960s With great expectations, I left Iowa City on Saturday 18 February 1967. Sunday I checked into the Paris Hotel on 96th Street on Manhattan’s Upper West Side, a large blocky building, past its prime, but inexpensive, so there was no rush to find an apartment. I walked up Broadway to look at the Goddard Institute for Space Studies (GISS), where I would report the next morning. It is a seven-story building on the northeast corner of 112th Street and Broadway, four short blocks from the center of the Columbia University campus, a walk of just a few minutes. The first floor housed Tom’s Restaurant, whose exterior was featured in the 1990s Seinfeld sitcom. No markings revealed a NASA presence. It was the Vietnam war era, with distrust of government growing, and Columbia students were agitated. A scratchy NASA film, The Universe on a Scratch Pad,23 catches the flavor of 1967 GISS. GISS was just acquiring the fastest computer in the world, the IBM 360/95 for $12 million (equivalent to $100 million today). Only one other 360/95 was built. The GISS version was special, with one million bytes of fast, thin-film memory in addition to four million bytes of core (magnetic donut) memory. The computer took up the entire second floor of the building. GISS attracted some of the best space scientists in the world. Besides the computer, extraordinary NASA support included about 25 NAS/NRC22 positions and 10 government scientist positions. Half of the NAS/NRC positions were post-docs; the others were visiting senior scientists from around the world. NASA willingness to allow GISS to be located in a vibrant academic environment, practically on the campus of a major university, was crucial.

Just days after I arrived at the Institute, Patrick Thaddeus, a senior scientist at GISS, burst into my office with an urgent question. Would I like to attend the Conference on the Atmospheres of Mars and Venus at Kitt Peak National Observatory? Was I willing to go in his place? His plane to Arizona was leaving from JFK in a few hours. Patrick handed me two slides and gave me a ten minute lecture on his laboratory results. It was extraordinary trust, which I puzzled about later. A GISS secretary changed the plane reservation to my name. I got my still partly unpacked suitcase from the Paris Hotel and caught a taxi on Broadway. The 1960s were a different era for travel. If you made it to the airport 10 minutes before departure, and ran, you could catch your flight – there was no security. 44 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 7.2. Patrick Thaddeus

This Kitt Peak Conference was historic, at the dawn of the planetary space age. Top scientists were there. Review talks were given by , D. Deirmendjian, Hyron Spinrad, Seymour Hess, Don Hunten, Frank Johnson and Richard Goody. Shorter talks on specific topics were given by Henk van de Hulst, Michael McElroy, Carl Sagan and others. The conference occurred just prior to the first successful space probes of the Venus atmosphere. All notions about conditions on Venus beneath its ubiquitous cloud cover were still on the table. Those models were (1) Sagan’s greenhouse model with water and ice clouds, (2) Opik’s dusty atmosphere model, including my variant with smaller aerosols and internal heat playing a role, and (3) Thaddeus’ dry massive model of carbon dioxide and nitrogen. I began writing my talk on the plane and finished it in my motel room at 3 AM, seven hand- printed pages that I read word-for-word. I focused on microwave and radio wavelength observations of Venus, Thaddeus’ lab measurements, and his interpretation. Pat suggested that I use half of the talk to describe my dust model, but I included only one paragraph on it at the end. The only remote observations of Venus that could penetrate its dense cloud veil were microwave and radio wavelength observations. The Sagan, Opik and Thaddeus models differed in their sources of atmospheric absorption and emission of microwaves on Venus. Sagan assumed that the water and ice clouds, as well as water vapor and carbon dioxide, caused the absorption. In Opik’s model, dust caused microwave absorption. Thaddeus assigned the microwave absorption to a high pressure mixture of carbon dioxide and nitrogen, which he measured in a lab at GISS. We did not yet have observations that would let us prove which model was right. My summary of this story was well received. I was relieved that I could answer the questions. Don Hunten, the most authoritative and caustic Kitt Peak scientist, delivered the review paper for the session on upper atmospheres. Mike McElroy, a Kitt Peak staff member, was the star young presenter. Irish, with dark-orange hair, McElroy received his Ph.D. in Applied Mathematics from Queen’s University in Belfast. He was articulate and self-confident as he paced the floor describing model results for the chemistry of the Mars atmosphere. At one point he interjected “I don’t claim to understand this better than anyone else.” Whereupon Don Hunten, with a smile, commented “Being modest today, are you?” McElroy was Kitt Peak’s golden boy, soon to be wooed by Harvard.

Carl Sagan evoked a different response. Hunten’s voice, in regard to a scientific issue, had a clear tone of disrespect toward Sagan. I was too shy to approach Sagan, but I talked with Jim Pollack at a coffee break. Jim received his Ph.D. at Harvard under Sagan in 1965. He was about my age, three years older, with an easy,

45 © 2020 James Edward Hansen. All Rights Reserved. low-key personality. He noted the similarity in our Ph.D. theses on Venus, each being thick and covering several topics. We became friends and I always sought him out at planetary meetings. Jim suggested that we have lunch with Carl Sagan. Sagan remembered our earlier letter exchange, and was reassuring in his interaction with an introverted, novice scientist. I liked him. My notes from the two-day conference nearly filled the 50-page notepad provided by Kitt Peak. My avid notetaking was spurred by speakers who were unable to interpret observations quantitatively, because of uncertain effects of light scattering in the planetary atmospheres. That’s what I worked on in Kyoto. When we look at a planet, we see sunlight reflected by the planet. However, Venus does not simply reflect photons (bundles of light) like a mirror. Most of the photons bounce off cloud particles, then bounce off the ground or bounce off other particles many times, before escaping in the direction of our eye. It’s called multiple scattering or radiative transfer, and is what I was modeling, simulating on a computer. Richard Goody, in recapping the conference, included a polite criticism of Henk van de Hulst’s work that raised eyebrows. Van de Hulst was the most accomplished scientist present, with the possible exception of winner H.C. Urey.

Van de Hulst, a Dutch astronomer, earned fame as a graduate student, when he predicted that neutral atomic hydrogen, the most abundant constituent of the universe, should have a sharp absorption line at wavelength near 21 centimeters (cm).24 Jan Oort at Leiden then used the 21 cm line to map hydrogen in space, discovering the spiral structure of our galaxy. Van de Hulst later wrote the definitive book25 describing light scattering by an individual particle. For about 15 years prior to the Kitt Peak Conference, he worked on multiple scattering of light, the problem I mentioned above. Goody’s criticism, or suggestion, was that there should be less emphasis on theory and more on practical methods to interpret observations. Joe Chamberlain, Kitt Peak Director, asked van de Hulst if he wanted to respond. Van de Hulst, a large man with unkempt dishwater blond hair, looking like the Dutch sailor he was, seemed to be puzzling as he walked from the back of the room. His response was soft-spoken. He said that his new book would include tables, formulae and computational suggestions to help users. Van de Hulst was an extraordinary scientist with superb mathematical skills and deep physical insight, as shown by many analyses in his peerless book on scattering by small particles, which were fundamental contributions. No doubt, he could also go further, using the scattering theory to interpret specific observations of planets, but that was not his objective. I could hardly sit still. I was excited by the opportunity to interpret planetary observations that was available to more ordinary scientists. It is a lot of work, with difficult computer programming, but appropriate for a post-doc. My scientific toolbox included computer programs based on Ueno’s approach. I wanted to try some of van de Hulst’s ideas, to try to develop and sharpen tools for my toolbox.

Back in New York, I went to see Pat Thaddeus to report on the Kitt Peak Conference. It was then that I realized why he had asked me to give his talk. Pat was a brilliant scientist, with infectious enthusiasm and an unusual ability to communicate with nonscientists. Like other great scientists, he began in science early, building a reflecting

46 © 2020 James Edward Hansen. All Rights Reserved. telescope from scratch as a teenager. He got a bachelor’s degree in physics from the University of Delaware in 1953 when he was 21, a master’s degree in theoretical physics as a Fulbright scholar at Oxford, and a Ph.D. under Charles Townes at Columbia University at the time Townes was completing his Nobel-prize-winning research on maser and laser emission.26 After cosmic microwave background radiation (CMB) was discovered in 1965, Pat developed an experiment to measure CMB from a ground-based microwave ‘telescope,’ that is,, an antenna that detects and measures microwaves. This led to a meeting in his office in 1974 with his post- doc John Mather, Michael Hauser and David Wilkinson about building a to measure the spectrum of CMB and its spatial variations, and eventually to the COBE (Cosmic Background Explorer) satellite – and later a Nobel Prize for Mather as project scientist. Pat Thaddeus deserved a Nobel prize for discoveries he made on a shoestring. He was a pioneer in astrochemistry. He defined absorption lines of hundreds of molecules from lab measurements and quantum mechanical calculations, and used this work to discover more than 30 molecules in interstellar space. Pat and his group built a 4-foot microwave telescope that they operated from a rooftop a few hundred yards from Broadway. With this telescope and a duplicate in Chile, they obtained the most extensive survey of the molecular Milky Way, leading to discovery of giant molecular clouds and a revolution in understanding of the interstellar medium and star formation. Venus research was a sideline to Pat. He was interested in working on the Venus problem, but only as a secondary topic to his first love, astrophysics. He needed a ‘planetary’ post-doc. I could not help him. I wanted to develop my own research. I wanted to write computer programs for light scattering by clouds and planetary atmospheres. Then I could interpret observations of other planets or measurements of Earth from a satellite. Pat wrote a short paper on his ‘dry massive model’ of the Venus atmosphere for the Kitt Peak conference book.27 When the Soviet Venera spacecraft landed on Venus it revealed that Thaddeus’ model was the closest to the truth. Almost nobody knows that. If you want credit for work in science you often must keep writing papers, refining your model to account for new data. Others will refine their models. Pat had no time for that, and no planetary post-doc. The atmosphere of Venus was found to be dry and massive, with surface pressure about 90 times that on Earth, closest to Pat’s interpretation. The clouds of Venus are sulfuric acid, not water ice. The greenhouse model was also partly right. Infrared-absorbing gases contributed to high surface temperature on Venus when it was young, but the proximity of Venus to the Sun was the most important drive – incident solar energy was twice as great as solar energy striking Earth. Venus was too close to the Sun for much volatile water to survive (as described in Chapter 10). Once Venus lost its ocean, the carbon in the planetary crust was baked into the atmosphere, yielding a massive atmosphere of about 96 percent carbon dioxide and 4 percent nitrogen. The model proposed in my Ph. D. thesis, with interior heat of Venus trapped by micron-sized dust kept aloft by slight breezes, was almost entirely wrong. Internal heat is not needed; the small portion of incident sunlight scattered down to the Venus surface is a larger heat source. There are micron-sized aerosols on Venus that affect the temperature profile of the atmosphere, but they are sulfuric acid, not dust. No breezes are needed to keep the aerosols aloft, because the aerosol droplets evaporate before they can fall to the surface.

47 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 7.3. Middle-aged Jim Pollack and Carl Sagan I should have guessed that the Venus clouds were sulfuric acid. A Japanese professor, Shotaro Miyamoto, whom I met during our year in Japan, told me in a letter in June, 1967 that the near- infrared spectra of sunlight reflected by Venus matched spectra for volcanic aerosols on Earth. The significance of that escaped me, but that is a story for my next book.

I was lucky to be invited to attend the Gordon Conference on the Physics and Chemistry of Space, held at the Tilton School in Tilton, New Hampshire, on July 10-14,1967. Gordon conferences are a luxury, a week on a specific science topic, with relevant experts. Mornings were for scientific presentations. Afternoons were unscripted, for informal discussion, often in the course of outdoor activity. After dinner we met for review talks and discussion. Jim Pollack suggested, on the first day, that we take a small boat out on the lake, a fiberglass sailboat, a Sunfish, with one sail. Occupants sit on the boat with their feet in the cockpit. One person steers the boat with a handle in the back that controls the rudder. Early afternoon is often a time of doldrums, no wind. That was o.k., we could talk about Venus – and about Carl Sagan. Carl would be in an uncharacteristically subdued mood when he arrived at the conference. He had recently been denied tenure at Harvard. We believed that the decision was unjust, that a special factor had come into play: the frequency that Sagan’s name and face appeared in the media. The media attention irked some colleagues. Someone at Harvard tacked a newspaper article on the departmental bulletin board, underlining in the statement “according to Carl Sagan the speed of light is 300 million meters per second.” What was the point? Is it bad to explain things to the media?

Did the treatment of Carl Sagan by his colleagues matter? The scientific community needs to communicate with the public and policymakers, especially in areas such as climate change. So it is important to understand why the scientific community was displeased with Sagan. Harold Urey was on Sagan’s tenure committee. As a Nobel Prize winner, his criticisms of Sagan are widely considered to have been decisive. Keay Davidson, in a monumental biography28 of Sagan, notes that Urey criticized Sagan for having “dashed all over the field of the planets” and for writing articles that were too wordy and had little intellectual meat. William Poundstone, in another excellent Sagan biography,29 says that the scientific relationship between Sagan and Pollack was so close that some likened it to the left and right sides of the brain, and, when Pollack left Sagan, moving to NASA Ames Research Center in California, one MIT scientist remarked that “the thinking side of the brain had moved to California.” 48 © 2020 James Edward Hansen. All Rights Reserved. I include this last remark as an indication of feelings of some colleagues. Sagan’s intellect was certainly on par with Pollack’s. Sagan attracted and stimulated the best students, including David Morrison, Clark Chapman and Brian Toon, who became brilliant scientists in their own right. Pollack, for example, Sagan’s first student at Harvard, scored 800 on his college math SAT (the highest possible score), was high school valedictorian, graduated from Princeton, and earned a master’s degree at Berkeley before entering Harvard’s graduate program. Sagan relished working with independent thinkers. He was not afraid to surround himself with the best minds. And he had too many ideas to work them all out himself. Sagan created a dynamism and synergism among colleagues that any university department would covet.

Unless there are other considerations. Jim Pollack and I talked about that on the Sunfish. Jim summarized his interpretation in one word: “jealousy.” He was convinced that jealousy of Sagan’s public profile was the determining factor. Carl Sagan was wearing a windbreaker when he arrived. With his long black hair, he looked more like James Dean or a rock star than a scientist, but he seemed downcast. His explanation: his apartment had been broken into, and he had lost an expensive camera. The subject turned to light scattering. Sagan and Pollack had just published a paper on a two- stream solution of the scattering problem, an approximation in which sunlight incident on an atmosphere is scattered in just two directions: straight up or straight down toward the planetary surface. This approach yields estimate for the amounts of radiation reflected by the planet, absorbed in the atmosphere, and reaching the ground. Carl was the first author of that paper30 and he deserved credit for its innovations. Inferences they drew about the Venus clouds turned out to be wrong. They incorrectly attributed near-infrared absorption to the Venus clouds; in fact the absorption was mainly by carbon dioxide. But this did not detract from the merits of their two-stream approximation. Years later, I found their two-stream method to be useful for many climate problems. When you shine a bright light on any scientist’s work, you can always find flaws. If there are no false steps, the scientist is not a good scientist – he is not pushing the envelope to new frontiers. This general topic – the constraining force that the scientific community exerts on information flow to the public – deserves greater study. It may literally affect the fate of humanity. We will return to this topic after gathering more empirical data.

Back in New York, I worked really hard on ‘light scattering.’ Ueno’s invariant imbedding method to calculate light scattering proved to be too slow for realistic aerosol and cloud particles. I went down a different path, guided mainly by Henk van de Hulst’s work, and by van de Hulst’s protégé, Joachim (Joop) Hovenier. Aerosols and clouds are important on Earth and other planets. Aerosols are second only to greenhouse gases in driving global climate change. I spent much of my career figuring out how to measure aerosols, but as yet we have adequate measurements for only one planet: Venus! Aerosols deserve their own book. When Sophie’s Planet became too long, I extracted most of the chapters on aerosols and clouds on Earth and other planets. These will be in my next book, my third book, whose tentative title is End of the Rainbow.

49 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 7.4. The author, age 26, photo taken for University of Iowa Physics Department.

I spent 12-hour days at GISS doing that research on light scattering and aerosols, often working until midnight, because the big computer was readily available in the evening. Of course, for me, it was not just work. When you realize you can make a difference, and learn something, as Feynman says, there is “the pleasure of finding things out.” For a long time I had no social life except going to dinner with other scientists, John Potter and sometimes Howard Cheney, at the Moon Palace just across Broadway or the V&T Restaurant on Amsterdam Avenue, which had the best pizza and cherry cheese cake in town. Fortunately, these were the days when journals were still on library shelves, not on computers. There must be something about librarians and scientists in the aisles of book shelves, because the encounter in the Columbia library was a near duplicate of that in Kyoto. Unfortunately, intimacy with this librarian did not last long because she was approaching the big 30, the age young women in those days feared reaching without a long-term commitment. I wanted to focus on becoming a scientist. The fact that we were both frank with each other only increased our mutual attraction, but we were equally stubborn. She introduced me to some of her girlfriends, but she knew they were less attractive than her.

Why didn’t Van Allen respond to my letter? In November 1967 I applied for an NSF fellowship to study under Prof. van de Hulst at Leiden Observatory in the Netherlands. Three months later, in February 1968, NSF informed me that they were still missing Van Allen’s letter of recommendation. Yikes – I remembered a letter Van Allen sent asking for a headshot photo for his book of Physics Department graduates. I had not responded, because I didn’t have a photo. So I had a photo taken at a photo shop near GISS, and Van Allen soon sent a letter to me, saying that he had sent NSF a favorable letter for my post-doc application. Whew.

It was my second summer in New York. I had to get outdoors and I had a great idea. A boat like the one Jim Pollack and I rented would provide a fantastic way to get sun and exercise. Then I could ask one of the beautiful girls at GISS to go sailing. Sunfish were sold nearby, in Connecticut, for about $1000. The boat is not heavy and would fit on my balcony. I had a one-bedroom apartment on Riverside Drive near 102nd Street, with a balcony in the back.

50 © 2020 James Edward Hansen. All Rights Reserved. I contacted Andy. He needed a break, so he would come to New York. It seemed he was having trouble with Prof. Matsushima. They did not see eye-to-eye on Andy’s thesis and paper writing. A Sunfish is easily ported atop a car. I had a mid-1950s Ford Fairlane that my mother found in Iowa for a few hundred dollars. So Andy and I picked up a Sunfish in Connecticut and took it straight to the 72nd Street boat basin, where we could drop it on the Hudson River, which at that point is actually a salt-water estuary about a mile wide. It worked great. There was a strong breeze. We got the boat to plane on top of the waves, like a surfboard. We were really flying. We also learned that it was easy to tip the boat upside down, by being a little clumsy in ‘coming about’ (changing direction so that the wind comes over the opposite side of the boat). The upside down boat is no problem. You just grab the daggerboard,31 push down on it, and the boat pops back up. Clumsy ‘coming about’ is a good trick to have in your toolbox, when you go sailing with a girl. You climb back in the upright boat, laughing, both soaking wet, and necessarily in very tight quarters. Just don’t tell her that you tipped the boat on purpose. Our problem occurred when Andy and I tried to carry the boat up the stairs to my apartment. The spiral staircase was too tight, the boat was too long. I called around and found two good places to keep the boat, safely, out of the water: on City Island or at Dobbs Ferry on the Hudson. Over the next few years, I used both of them.

Sailing with your sister is a different deal. No point to tip the boat over. Lois, sister #3, stopped by New York, I believe on her way to or from Afghanistan. She spent a year there and wrote her Ph.D. thesis at Northwestern on women in Afghanistan. She stopped in New York to see an Afghan professor at New York University. Anyhow, we picked up the Sunfish from Dobbs Ferry and brought it to the 72nd Street boat basin. Even my skinny sister could help me load it on and off the Fairlane. It was late afternoon, so we stayed on the Hudson until after sunset. The New York skyline was remarkable. “Can you believe where we are?” Lois said, thinking back to when there were nine of us living in the little house in Denison. It was a change for sure. I was never on the water in Iowa. Other kids talked about Lake Okoboji and Clear Lake, but I never saw either one. I only saw the Denison gravel pit. I drove there on my bicycle, with a cane pole, fishing for a flat fish – sunfish. Today I see few such little boats in the water around New York. Something is fishy. Are such simple pleasures unaffordable to young people today? Wealth disparity, obscene college costs, debt, reduction in the size and level of the middle class? We need a less subjective measure than the apparent number of small boats. Let’s come back to this topic later.

Dr. Jastrow, Director of GISS, called me to his office in late 1968, months before I left for the Netherlands. He told me that his senior staff recommended that I be hired as a NASA civil servant upon return from Leiden University. Prof. Van Allen, in his letter in March, had said that he hoped I would consider an Assistant Professor position at Iowa after I finished the NSF post-doc position. My heart was in NASA, in space, even being an astronaut. I accepted Dr. Jastrow’s offer instantly, never imagining the troubles that would flow from that choice.

51 © 2020 James Edward Hansen. All Rights Reserved. Chapter 8. The Netherlands

Light scattering was the focus of my research for the next several years, especially how sunlight becomes polarized when it is scattered by aerosols and cloud particles. A wealth of information about the scattering particles can potentially be extracted from polarized light. Although human-caused aerosols are an important driver of climate change, second only to greenhouse gases, the focus of my aerosol studies in those years was on planetary science. Planets are interesting, but it is a long story, and we need to get on to the crucial topic of climate policy. So I will minimize discussion of that research. On the other hand, I should avoid a discontinuity in which I suddenly appear with a family. So I provide a little personal information on the few years following my post-doc years in New York. I suffered some bitter disappointments in those years, including the withdrawal of the offer to join the GISS staff. However, they were still the best years of my life, because that is when I met Anniek, who is the best part of my life. She also changed the course of my scientific career. It is unlikely that I ever would have got a NASA job at the Goddard Institute without her influence. She comes into my story in Leiden.

The Sterrewacht, the astronomical observatory of the University of Leiden, was located on the inner side of a canal encircling Leiden. Also on the inner side of the canal, within walking distance of the Sterrewacht, was the Parksicht (Parkside) Hotel. The Parksicht looked like a large house – no doubt it was an impressive home for a wealthy Dutch family during an earlier era. A room on the second floor had been reserved for me, when I arrived on March 10, 1969. I would live there my entire stay in Holland. The next morning I walked along the canal. Near the Sterrewacht the canal broadened into a peaceful scene, with ducks and swans on the water. There was a two-story white house of moderate size next to the Sterrewacht. Its lawn spread out like a fan toward the canal. Morning tea time was already underway at the Sterrewacht, a ritual to encourage interactions. Young researchers unsure about their progress tried to position themselves to avoid contact with the elder statesman, Jan Oort, who might ask about their research. On this day there was a tray of rusks, circular toast topped by pink candy bee-bees, celebrating birth of somebody’s baby girl. Oort, a pioneer in radio astronomy who made significant contributions to understanding of the Milky Way, was born in 1900. So, I am now startled to note, he was only 69 on that day, a decade younger than I am today. Students considered Oort to be ancient. He still used tables of mathematical functions for his calculations, having developed his habits prior to the slide rule era, which was succeeded by the computer era. Hendrik (Henk) van de Hulst, Oort’s student, was 50 years old. Leadership of the Sterrewacht had just transitioned to van de Hulst, whose family lived in the house that I saw as I approached the Sterrewacht that morning. The optical telescope at the Sterrewacht had long since become irrelevant to astronomy, succeeded by larger telescopes on mountains. Research at the Sterrewacht had become focused on data from a radio telescope in the Dutch countryside. I spoke with Joachim (Joop) Hovenier at tea. Joop was an advanced graduate student, married, with two young children, methodically closing in on his Ph.D. degree. Joop would be my 52 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 8.1. Anniek in 1969 teacher in Leiden. Scholarly expectations for a Ph.D. in the Netherlands are high, and Joop was already one of the top experts in the world on polarized light – but that science is another story.

The story besides light scattering started with the Sterrewacht librarian, of course. She was very sweet, and I asked her to dinner. She knew an interesting place in the Hague, named 1001 Nights, I believe, a restaurant and bar with an elderly black piano player. A man sitting alone at the table next to us must have been a frequent patron, as he bantered with the piano player, requesting specific pieces or just “play it again, Sam.” He used Dutch, French and English during the evening, so, as a mono-lingual American, I understood only part. He said that he was with IBM, had been an architect of an early computer, and currently had apartments in a few European cities where he was a sales representative for IBM. Before the evening ended he offered us the key to his Paris apartment, which we could use for the weekend. It was going to be a beautiful spring weekend. We accepted. She would return the key to him at his office in the Hague. He asked only that we replace the wine, if we drank any. We drove to Paris the next day, to his apartment, which was near the River Seine. Sun streamed in when we opened the doors to the balcony the next morning. A young man on the street was carrying a sack of fresh French bread. We went down for coffee and a closer look at the scene. The atmosphere along the Seine was Bohemian, but without the edge of anger that was apparent in New York City. The French had cleverly willed the problem of Viet Nam to the brash Americans. A white mouse peaked from the unkempt hair of a hippie. I cannot remember much else about that trip. There was no real Paris springtime romantic flame. I was still thinking about librarian #2, in New York City. I spent time reading papers on scattering and the clouds of Venus, and was thinking on these topics as we drove back to Leiden. My companion surely thought I was strange.

Back in Leiden, I needed to give a talk at the Sterrewacht, as was expected of visiting scientists. I was not ready to talk about polarized light, the subject that I was beginning to study in Leiden. However, I had a paper32 in press that tested several multiple scattering approximations that van de Hulst had proposed; I compared these with exact numerical solutions that I had calculated on our big computer in New York. I could have spoken on that safe topic. Instead, I chose to speak on near-infrared scattering by terrestrial clouds, from a paper that Jim Pollack and I were working on. Nothing exciting, just accurate computations using the computer

53 © 2020 James Edward Hansen. All Rights Reserved. programs that I developed while in New York, and comparison with aircraft observations of water and ice clouds. Our computations used spherical cloud particles, because spheres were the only particle shape with an available solution for the scattering diagram of a single particle. During my talk a graduate student asked technical questions: “How would the effects of dichroism change the result? What about birefringence?” I should have given a simple answer. It made sense for a first study to ignore such complications that arise for crystalline ice particles, and make computations for the simplest case, homogeneous spherical cloud particles. Instead I stumbled in technical details. I had not prepared for questions with, what seemed to me, a nasty intent to make the Yankee visitor look foolish, an objective in which I felt he’d succeeded. That low point was short-lived. Late that day I was still in my office, as usual, when the librarian appeared, saying there was someone she wanted me to meet, someone, as it turns out, she had recently met herself. They had met at a concert, which they both attended alone, happened to sit beside each other, and got into conversation. I only learned this 50 years later while writing this book, and have not sought to learn further about their conversation. I prefer to simply think of the librarian as a sweet, purposeful cupid. I went with the librarian to the room in the Sterrewacht where coffee and tea were prepared, and was introduced to 26-year old, blond, beautiful Anniek Dekkers. We were standing by the counter, rather apart, and our conversation was rather stiff. The librarian said that she had told Anniek of my interest in sailing – I must have told her about my Sunfish – and Anniek could tell me about a place where she had taken sailing lessons. I suppose that I was still depressed about the seminar. Anniek remembers that I looked washed- out, that I badly needed to get out in the sun. I took her contact information and said that I would contact her when I had time for sailing. I did not say so, but in fact I did not expect to have any time for sailing in Holland. Fortunately, as we took leave we smiled at each other, and that is a moment that we both still remember. I could not forget how attractive she was, and she decided that with my mop of brown hair, if I smiled, I was actually appealing.

Soon thereafter I was walking down cobblestone streets looking for her apartment. First I had to find Pieterskerk, a huge, old church. I mean really old. Pieterskerk was the church of the Pilgrims and their gathering place before they left on the Mayflower to establish the second successful colony in the New World, in 1620, at Plymouth, Massachusetts.33 From Pieterskerk it was less than 100 meters down narrow Herensteeg to the apartment I was looking for. Her apartment was once the stable for the larger attached home, the brick and stone buildings on the Herensteeg forming a continuous front. A long narrow window above the old stable door, about nine feet above the ground, provided a modest amount of light into the apartment. The stable door was permanently sealed, but beside it was a buzzer and smaller door into a hallway leading to the ground floor apartment and stairs to an upstairs apartment. Anniek had the ground floor apartment, which was as wide as the stable door. The back wall of the apartment had a sliding glass door that opened into a small courtyard, large enough for a table, chairs and flowers. Inside, sitting on the floor mat, was a large brass pot with candles on the bottom, which was Anniek’s preferred lighting in the evening, at least if she had visitors. It was already late, when I arrived. She had to get up early the next day – she was teaching at a combined junior and senior high school – but I got a dinner date for the weekend. Recently, 54 © 2020 James Edward Hansen. All Rights Reserved. when an interviewer asked Anniek what she remembered about our first date, the first thing she mentioned was that I informed her that I did not plan to get married until I was 40 years old.

That may have been a powerful anti-aphrodisiac. It was an exceedingly long courtship. I began visiting for tea in the evenings, after I had finished at the Leiden University computer center. I was not the only visitor. Her students sometimes stopped by – and other friends. One time, after I had visited several times, I noticed a face peering in the window above the stable door. I told Anniek “don’t stare, but there’s a nine-foot tall man peeking in your window.” She needed only a sideways glance to identify the landlord, before he disappeared He must have been standing on a bicycle or a step stool. He owned several buildings on the street. He had decided that Anniek was the ideal wife for his son, who was about to graduate from medical school as a surgeon. But maybe she was not as perfect as he thought. What was going on with this frequent Yankee visitor? There wasn’t much. She told me not to worry about the landlord. She was not interested in the son, who was “very dull” and “very old” (he was 32 years old). Fortunately, NASA arranged to have its first moon landing that summer. Anniek did not have television, so we watched the landing together in the Parksicht Hotel, the Eagle setting down on the lunar surface at about 9 PM, Dutch time, on 20 July. It would be about six hours before Neil Armstrong would emerge from the capsule and flub his line, omitting the article “a” as he sat his boot on the moon with “one small step for [a] man, one giant leap for mankind.” Six hours. A lot can happen in six hours. In the official version, Anniek says that we watched the first step on the moon together. In reality, although my NASA engineering colleagues may question my priorities, we watched a rerun, because we had fallen asleep in each other’s arms.

Two months earlier, in May 1969, I had attended a COSPAR (Committee on Space Research) meeting in Prague.34 Jim Pollack also attended that meeting, where we talked about our paper on infrared spectra of clouds. In a letter to Pollack about that paper in June 1969, I described a “dilemma.” Several weeks earlier, the New York librarian suggested that we meet in Italy, where we could vacation together. I tentatively agreed, but told him that since then had met a “terrific little blonde.” Anniek might object to that, especially the “little” part – she was 5’4”tall. Jim never answered my dilemma. It did not matter. I was smitten with Anniek, I decided against the vacation trip. When I left the Netherlands on about 1 September 1969, we planned for Anniek to visit New York during the winter holiday season, imagining a wonderful time in the city. We had no idea how my situation in New York was about to change.

After I returned to GISS a confrontation occurred in Dr. Jastrow’s office. The issue was whether computer programs that I developed were communal property. I did not agree that they were. I should have anticipated the problem and been ready with a diplomatic response. I then foolishly asked if I was in charge of my research on Venus clouds. Jastrow’s answer was a thunderous “No!” He then told me to see Rasool or Arking, GISS senior staff members, about employment arrangements, as I was effectively told to leave Jastrow’s office.

55 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 8.2. Wedding photo taken by Joop Hovenier in January 1971. I was 29 and Anniek 28. Right: Anniek gathering dinner on the last day of our honeymoon.

About six weeks later I began to be paid as a Columbia University research associate; the NASA position had apparently disappeared. My response was to work hard on my computer programs. I wanted to finish a study of the Venus clouds, in case I would not continue to have use of the big NASA computer. The Venus story is complicated. As I read letters from that time, I see my immaturity. I made mistakes and have regrets and compunctions. I will tell that story in End of the Rainbow.

My joy in that period was Anniek, who visited twice, before taking a leave of absence from her school to work one year as an au pair for a family in Bronxville. Ichtiaque Rasool, who had become de facto deputy director of GISS, and his French wife, Francoise, liked Anniek. Ichtiaque said he had two tickets for the launch of Apollo 14, from the VIP viewing stand at Cape Canaveral, but was too busy to go. Would I like to have the tickets? This was the perfect opportunity to propose to Anniek. A honeymoon at an Apollo launch would be ideal. Anniek found a little Catholic church in the Bronx with a very Irish priest. We were married in January 1971 with Joop Hovenier as witness. Two days before the end of our one-week honeymoon in Florida we ran out of money and my credit card would not work. As always, whenever there is a problem, Anniek becomes even more radiantly positive. We lived two days on fruit we could find growing by the Florida streets. Anniek created an environment in which I could grow professionally, making up for some of my social deficiencies. Indeed, she changed my prospects at the Goddard Institute. Her effect flowed naturally, from her love and concern for other people.

56 © 2020 James Edward Hansen. All Rights Reserved. Chapter 9. Getting a Job

My route into NASA involved two curious characters, Ichtiaque Rasool and Stephen Schneider, the route passing through a hypothetical ice age on Earth. The first of these, Ichtiaque Rasool, was one of the initial GISS staff members. After receiving his Ph.D. in France for research in atmospheric ozone, he was offered a post-doctoral position at GISS by Dr. Jastrow. He arrived in May 1961, the month that GISS was formed in New York. Ichtiaque’s engaging personality and good humor were perfect for interacting with visitors, and Dr. Jastrow came to rely on Rasool as an unofficial deputy for administrative purposes. Anniek suggested that we invite Ichtiaque Rasool and his wife, Francoise, for dinner at our apartment in the Bronx. My commute to GISS took an hour or more, via a bus and the noisy, rattle-trap IRT Broadway subway (now #1) line, which was then rated as the worst subway line in the city. However, by living that far out we could afford a one-bedroom apartment, on Palisades Avenue in Riverdale, with a balcony and a view of the Hudson River. Anniek made paella, which was great, for our dinner with Rasools. We had only plastic ‘silverware,’ but Ichtiaque’s only complaint was “the wine service at this place is a disaster!” I did not refill his wine glass quickly enough. The Rasools’ partiality toward Anniek improved my chance of getting a job with NASA. Anniek, however, was having a hard time finding a good job. Given her background in teaching fashion, the fashion industry was the logical employer. She tried a few places. Each time it was the same – male supervisors. An attractive young woman was soon asked to come in on weekends, when other employees were not around. Because of her talent, rejecting a supervisor’s overtures would not cost her job, but it prevented advancement. Changing her employer did not fix that problem – it was the same deal. She gave up on the fashion industry and found more productive activities. More on that later.

Rasool would soon be Editor of the Journal of the Atmospheric Sciences. Dr. Jastrow continued as official Editor for a time, but he ceded most of the work to Associate Editor Rasool. Rasool finally demanded the Editor title. He became Co-Editor in 1971 and Editor in 1972. Rasool needed Associate Editors willing to work, not just be names on the journal’s masthead. He decided I was a good candidate, probably because I had written several papers that passed the journal’s peer review process. I did not realize what I was getting into. A folder with a new paper would arrive on my desk. I had to identify two appropriate reviewers, prod them, and find a third reviewer if the first two disagreed on whether the paper merited publication. Doing a conscientious job led to more folders arriving on my desk with new papers. The Associate Editor job became a time sink, but it meant that Rasool was aware of me. Rasool sometimes attended meetings in Jastrow’s stead, but Dr. Jastrow chose not to have an official Deputy Director. Thus, without recognition and salary commensurate with his duties, Rasool began to chafe in his position. Fortunately for me, Rasool hung on at GISS a bit longer. Unfortunately, it meant that I had to continue doing favors for Rasool. One specific request sticks in my mind. Rasool called me to his office, where he was in animated conversation with a bright young post-doc, a certain Stephen Henry Schneider. 57 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 9.1. Steve Schneider at National Center for Atmospheric Research (circa 1972)

Steve Schneider was gregarious and good-looking, with bushy, curly dark hair. Articulate and self-confident, he had been a student negotiator with the Columbia University administration when students protesting the war in Viet Nam took over several Columbia buildings. I already knew Steve, who was around GISS while finishing his Ph.D. in Applied Physics. I thought he talked too much. Sometimes, after he was in my office a while, I’d impolitely turn away and try to work, but he did not take the hint. He’d continue an unbalanced conversation. When Anniek came to my office, she enjoyed talking with Steve. She said he was a nice guy, he just craved attention. I encouraged her to take him down the hallway and talk there. Anniek persuaded me to go for a hike with Steve. The three of us climbed Storm King Mountain on the Hudson, with Steve acting as a tour guide. I began to like him and we became friends, but only as time went by did I begin to appreciate the enormous contributions Steve made to the field of climate science. Steve was the closest thing we had to a Carl Sagan in climate science. I should have tried to learn more from Steve early on, rather than working entirely on technical stuff. Had I been more insightful, I would have attempted to emulate at least a smidgeon of his loquacity, but I did not.

Rasool wanted to write a paper comparing the climate effects of aerosols and greenhouse gases. Human-made aerosols, the fine particles in the air that cause visible air pollution, scatter sunlight in all directions, some of it back to space. By reducing the amount of solar energy absorbed by the planet, most aerosols on Earth have a cooling effect. Greenhouse gases such as CO2 are transparent to incoming sunlight, but they absorb Earth’s upwelling heat radiation, so they act like a blanket,35 warming Earth’s surface. Which effect is bigger: human-made aerosol cooling or human-made greenhouse gas warming? That was Rasool’s question. Rasool had done crude greenhouse calculations for other planets, so he thought that he and Steve could handle the greenhouse part of the problem. Scattering and absorption of sunlight by aerosols was another matter. Rasool knew that I had written several papers on that topic, so his idea was that I should give Steve a computer program and teach him how to run it. That was a bad idea. It would be like cracking a peanut with a sledge hammer. My programs were huge, thousands of lines of code, thousands of computer cards. The programs were designed to calculate radiation emergent from the atmosphere at different angles to high precision. Such high accuracy is needed for the sake of extracting maximum information from polarized light, because polarization can be measured to one-tenth of one percent accuracy. 58 © 2020 James Edward Hansen. All Rights Reserved. Such accuracy was meaningless in their calculation, because the input aerosol properties were highly uncertain. I suggested that Steve use a simple “two-stream” calculation, and I gave him the equations, which I got from a paper by Sagan and Pollack on the clouds of Venus. The two- stream solutions were accurate within several percent for the solar radiation reflected by the planet, absorbed at the surface, and absorbed in the atmosphere. The two-stream equations take only a few seconds on a computer, and they allow other people to easily repeat the calculation with alternative assumptions about the aerosols. Rasool and Schneider also needed input data about aerosols for the two-stream equations. They needed to know the fraction of the of sunlight striking an aerosol that is scattered (termed the ‘single scatter albedo’ – the remaining fraction being absorbed by the aerosol), and they needed to know a parameter that defines the portion of scattered light that goes into the forward hemisphere as opposed to being backscattered. Gustav Mie, a German physicist, defined an exact solution for those quantities, if the aerosols are approximated as homogeneous spheres. It is a ‘messy’ solution, because it includes a large number of terms, but I had written a computer program for the Mie solution for use in Venus cloud studies. I could have taught Steve to run my Mie scattering program, but it was easier just to do the calculations myself and make tables for the two desired quantities as a function of the particle size and refractive index.36 Steve then used these quantities as input parameters for the Sagan and Pollack two-stream calculations.

Rasool and Schneider’s paper37 was a disaster. They concluded that “even an increase by a factor of 8 in the amount of CO2, which is highly unlikely in the next several thousand years, will produce an increase in the surface temperature of less than 2°C.” Their paper was the lead report in Science magazine on 9 July 1971. Its abstract stated “Because of the exponential dependence of the backscattering, the rate of temperature decrease is augmented with increasing aerosol content. An increase by a factor of 4 in global aerosol background concentration may be sufficient to reduce the surface temperature by as much as 3.5°C. If sustained over a period of several years, such a temperature decrease over the whole globe is believed to be sufficient to trigger a new ice age.”

Their calculated CO2 warming was too small by a factor of three, even though authoritative analyses by Manabe and others were well known. The “exponential” aerosol backscatter was nonsense. The backscattering they refer to in their abstract is not the backscatter by a single particle, but rather the backscatter by the planet, which they computed with the Sagan and Pollack two-stream equations. Backscatter by the planet increases slower than linearly with aerosol amount. They graphed temperature change linearly on the vertical axis, but used the logarithm of aerosol amount on the horizontal axis. The graph made it seem that cooling increased rapidly, but in fact it increased more slowly than linearly with aerosol amount. They mischaracterized their own graph.

Their conclusion – that a CO2 increase by a factor of eight yields global warming less than 2°C – implies a warming of about 0.6°C for each doubling of CO2. If there were no climate feedbacks, Earth would need to warm 1.2°C to restore Earth’s energy balance with space due to the CO2- induced reduction of heat radiation to space caused by one doubling. They were asserting that the climate system has a net large negative (diminishing) feedback. Other researchers had shown that the climate system has strong positive (amplifying) feedbacks – for example, a warmer 59 © 2020 James Edward Hansen. All Rights Reserved. planet has more water vapor in the air, and water vapor is a strong greenhouse gas. Global climate sensitivity was estimated by most researchers to be in the range 2-4°C for doubled CO2, several times larger than Rasool and Schneider’s 0.6°C. How could their paper have been accepted by Science? Well, radiation calculations are a bit esoteric for many scientists. The “two-stream” equations that I gave to Steve, which they included in their Science paper, yield radiation fluxes moving in two directions: up and down in the atmosphere. These equations include exponential terms. Perhaps the referees did not have good intuition about radiation and did not check the Rasool and Schneider graphs carefully. Despite this, the Rasool and Schneider paper was useful in drawing attention to the competing effects on global climate caused by human-made greenhouse gases and human-made aerosols. Greenhouse gases and aerosols are the two main factors driving long-term climate change.

Steve and I learned something from each other. When Steve was thinking of putting aerosols into his climate calculations, he pointed out a paper38 by Charlson, who concluded that we do not know whether aerosols cool or warm the planet. Charlson was right to point out various uncertainties, but he made it seem like we could not draw any conclusions. My suggestion to Steve was to reframe the problem in a more intuitive fashion. Joop Hovenier had pointed out to me how Henk van de Hulst, instead of following the herd in analyzing a problem, frequently would start from scratch with a fresh look at the problem. Often he came up with a more insightful approach, finding a solution that evaded others. Reframing is a valuable approach in many public problems, not just in science. Bureaucracies and entrenched interests grow, and academics like to pile on pet ideas and methods. Problems become messy and esoteric; only the initiated understand the terminology. Simplifying a problem to its essence becomes crucial. We will return to this reframing topic often. For the issue of whether aerosols heat or cool, I suggested that Steve had a better chance of getting a persuasive answer by framing the problem in terms of Earth’s energy balance. The variables would be Earth’s surface albedo, i.e., the fraction of incident sunlight reflected by the surface, and the albedo39 of the atmospheric aerosol layer. Multiple reflections between the surface and aerosol layer can be included as the sum of a simple power series,40 if it is assumed that reflected light is isotropic (uniform in all directions). I had tested the impact of that assumption on the global energy balance with my detailed radiation computer program and found it to be accurate within several percent in typical cases. Steve wrote a short paper41 on this albedo formulation neglecting to acknowledge that I had written down the equations for him. Later he gave a seminar at Columbia University during which he acknowledged publicly that I had suggested the formulation, ending by looking at me and saying “there, I have done it.” It was a minor matter, which I had not complained about. But Steve demonstrated a depth of character. Saying ‘sorry’ can be difficult; saying it publicly is even harder, but it beats carrying regrets forever. Undeterred by the hullabaloo of his paper with Rasool, in September 1971 Steve wrote a letter- to-the-editor that was published in the New York Times. He was criticizing an op-ed that amounted to an ill-founded harangue aimed at environmentalists’ concern about air pollution and scientists’ concern about climate change.42

60 © 2020 James Edward Hansen. All Rights Reserved. Dr. Jastrow was incensed to see a letter in the Times that he had not approved. He promptly called a meeting of all GISS personnel. It was standing room only in the GISS conference room as Dr. Jastrow angrily warned everyone that all such publications required his prior approval. Steve, at that moment, was at NCAR (National Center for Atmospheric Research) in Boulder, Colorado, at the invitation of Will Kellogg, a senior NCAR scientist who took a shine to Steve. Jastrow got Kellogg on the phone: “Is Schneider there?” “Good. Keep him. I just fired him.” Steve’s job at GISS was saved, temporarily, because he had an official appointment from the National Research Council. However, in 1972, after Kellogg arranged a position for him, Steve moved to NCAR. It was a good move, as there Steve was able to work with the brilliant, low-key Bob Dickinson, perhaps the most outstanding atmospheric and climate scientist in the world. Steve had the guts to follow his instincts, retaining a fondness for media attention and refining his communication skills, even when that irritated colleagues who wanted scientists to stick to science. Steve founded a highly respected journal, Climatic Change, remaining editor the rest of his life. Steve was ingenious in using the journal and his professorship at Stanford University to expand climate science from being a physical science to become broadly interdisciplinary. He attracted and inspired countless young people to become scientists, and he helped inform the public about climate change and its implications. He showed all of us in the research community that it was possible to speak out publicly, ignore criticism from straight-laced scientists, and earn the respect of the broader community. Steve provided an invaluable public service.

Rasool did not last as long at GISS as Schneider did. Ichtiaque’s private explanation for leaving was that he could not stand waiting on the couch in Jastrow’s outer office – Jastrow frequently made people wait to see him, even if they had an appointment. Perhaps a more substantive reason was the fact that he was doing much of the Director’s job, but getting no recognition for it. Jastrow had not come through with the official Deputy position. Bob Kraemer, the Planetary Program Director at NASA Headquarters, offered Rasool a job as his Deputy. It would be an increase of annual salary from $16,000 to $31,000. Ichtiaque was delighted that he and Francoise would be able to travel more frequently to France. He could not turn it down, but his heart remained, in part, at GISS. He imagined that he would come back one day. Working at NASA Headquarters might provide a route back to GISS at a higher level. Rasool’s departure from GISS seemed like a disaster for me, as he was unable to push my civil service hiring through before he left. Fortunately, he retained leverage on GISS. In his new job at Headquarters, he would determine whether GISS continued to receive planetary research funding. Rasool informed Dr. Jastrow that I was the only one at GISS who justified continuation of the planetary funding, which included enough money to support two scientists. Dr. Jastrow’s view also may have been affected by the fact that I published six papers in 1971, and I was invited by Phil Abelson, Editor of Science, to write a review article on the clouds of Venus. Such an article is an honor, allotted 5000 words and several illustrations. And Jastrow was aware that the Planetary Division at Kitt Peak National Observatory had contacted me about interviewing for a possible job there. Finally, Dr. Jastrow had acquired the computer program for the UCLA atmospheric general circulation model. He wanted to improve the model and run it on the GISS computer for weather

61 © 2020 James Edward Hansen. All Rights Reserved. predictions. I seemed to be the best person at GISS to understand the UCLA calculations of solar energy deposition in the atmosphere and try to improve upon the UCLA formulation. Milt Halem, who managed the weather prediction project, was effervescent in praise of Jastrow for reconsidering the fate of someone who was in Jastrow’s “doghouse,” to use Halem’s word. I was less overwhelmed by Dr. Jastrow’s magnanimity, but I held my tongue. I was hired by NASA in March 1972, more than three years after the job was proffered in late 1968.

A government job is a plum. For all practical purposes, a person hired into the civil service system receives a lifetime appointment: it’s a bad system. Supervisors spend most of their time dealing with weak performers, who are exceedingly difficult to dismiss. The system is upside down. A talented scientist tends to shun taking a supervisory position in a government lab, because of the time he or she must spend dealing with poor performers. It should be the inverse; a leader should work with the most talented people in the organization. I mention this because young people should understand that our government badly needs reform, even NASA, which may still be one of the better government agencies. Why do you think NASA cannot launch an astronaut into space today, and must go to the private sector, to Elon Musk, for example, to get an affordable launch system. The civil service system is part of the problem, as is the fact that the budgets of NASA Centers are protected by the Senators and Representatives of their state. I describe these problems in more detail in End of the Rainbow. GISS, as a small NASA laboratory in New York City, operated differently than all other NASA Centers. The civil service scientist staff was small, at most 10-20 scientists, while the total number of people at GISS was in the range 100-200, a population that included students, post- docs and research associates paid via grants and cooperative agreements with universities (mostly Columbia). There was also a support services contractor that employed computer operators, programmers, librarians and other support personnel.

Those were the employment options when I joined the civil service staff in March 1972, at age 30, exactly five years after arriving at GISS. The planetary research funding that Rasool left for me was enough to hire two people on ‘soft’ (non-government) positions. My preference was for high-potential young physicists. The rationale was that physics is the best background education, producing scientists who are able to shift readily from one research area to another. My first hire was Andy Lacis. Andy’s Ph.D. thesis was on modeling the structure of a star, but he was happy to move in a new direction, to work on planetary atmospheres. The second was Larry Travis. I did not know Larry before then, but Andy identified him as the best of the physics students at Iowa in the classes that followed ours. Andy, Larry and I were known as the “Iowa mafia” within GISS. We had each been A students in science, but were not so similar otherwise. Larry and Andy were from eastern Iowa cities, while I was from rural western Iowa. Larry was the most articulate. When I hired Larry I already knew that I wanted to prepare a proposal for an experiment for a planned Pioneer spacecraft mission to Venus. Larry’s communication ability would be essential.

62 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 9.2. Tracing polarization contours for Space Science Reviews article on a light table.

Rasool extracted a ‘pound of flesh’ in exchange for the planetary research funding. He was becoming an editor of Space Science Reviews, and they wanted a review paper on ‘Light Scattering in Planetary Atmospheres.’ This was a big task, equivalent to writing half a book, which I worked on at home in the evening and on weekends. Anniek did not object. I said that we would have a more normal life, after I paid off my debt to Rasool. She took a photo (Fig. 9.2) as I diligently traced a polarization diagram for that paper.

Polarization of scattered sunlight is a complex topic. Light consists of electromagnetic waves that vibrate in the plane perpendicular to the direction of light propagation. The electric vector of unpolarized light vibrates equally in all directions in this plane. Sunlight arriving at Earth is unpolarized, but when sunlight is scattered by a particle or reflected by the ground it becomes polarized, and the nature of that polarization contains a great deal of information on the scatterer. Unlocking that information requires measurement of the polarization with an accuracy of the order of 0.1 percent. The polarization measurements should be made at several wavelengths covering the solar spectrum from the ultraviolet to the infrared. It is also necessary to observe the region under study from a range of different scattering angles, as can be achieved with observations from a spacecraft in orbit about a planet. Polarization was my principal area of study for several years. I was fortunate to have Joop Hovenier as instructor in the theory and David Coffeen as adviser on instrumentation. David had worked with a small group at the Santa Barbara Research Center (SBRC) in Goleta, California, on the construction of a polarimeter that flew on the Pioneer Jupiter mission. We worked with the SBRC group in constructing instruments for planetary missions in following years. Polarization of light is not going to be described further in this book, because, as yet, that science is tangential to the topic of Earth’s climate. I mention it here because it was the focus of my research in Leiden and during the following few years. This research led to successful proposals for polarimeters on the Pioneer Venus mission and the NASA mission to Jupiter. Without these planetary experiments, the Goddard Institute would not have survived. I have written several chapters on the research and struggles associated with these planetary missions, as well as satellite wars on planet Earth, which I will include in End of the Rainbow. But first a few personal events from that period. I also want to provide a simple summary of the scientific method, which seemed clear to me by that time.

63 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 9.3. Anniek with Erik three days after his birth.

Anniek and I had passed our 30th birthdays. Anniek let me work long hours, which was necessary as I worked simultaneously on planetary research and proposals, solar radiation for the GISS weather model, and the article that I owed Rasool. Despite increased responsibilities, there was less stress than in the years before I had a government position. And I must say there is little in the world as wonderful as making love when you have both decided that you are ready and willing to bring another life into the universe. 27 October 1973: Anniek was within a few days of expected delivery date when my sister Lois visited. We went for a drive to see the fall foliage. We all three had birthdays on the 29th of a month, so we wondered if the baby would wait two days. We did not figure on the bumpy ride due to the worn out shock absorbers on our old Ford Fairlane. Anniek began to feel contractions. We decided to have dinner near the hospital, Lenox Hill, on New York’s East Side. But when we called the doctor, he said: “go to the hospital immediately!” We had taken a class so that I could be in the delivery room, supposedly helping with Anniek’s breathing. Anniek insisted on being awake for it all, taking only an oral pain reliever. The baby was positioned coming out head first, with broad shoulders, a boy, Erik Edward Hansen, born at 11 PM. Anniek breast-fed Erik and handled almost all the child-rearing. I did change diapers, although Anniek says that I did not do my fair share, and she’s probably right. When Erik was two years old we used our savings, $5000, as down payment to buy a $24,000 two-bedroom apartment in a 24-unit co-op, an ivy-covered building on the corner of 116th Street and Morningside Drive. This solved the commuting problem. It was only a five-minute walk to my office. However, owning an apartment in a co-op accomplished much more. Anniek had given up on the male-dominated Seventh Avenue fashion and garment industry. Instead she made opportunity from our obligation to provide service to the co-op. She became building manager, supervising the super, with guidance from long-term resident, Prof. Walter Gellhorn of the Columbia Law School. The Greenhouse Nursery next door provided child care, which gave her time to work on remodeling the apartment, which had been long neglected. The degree of my help is revealed by an event that she related43 to Nathaniel Rich. Anniek directly undertook most of the work fixing 64 © 2020 James Edward Hansen. All Rights Reserved. up the apartment, but I was assigned the ceiling, which required standing on a tall ladder, sanding the cracks, and plastering. One area in the ceiling sagged ominously. It was once water-damaged by a leak in the apartment above. We forbade Erik to go near the sagging part. A good thing. It came thundering down one night, destroying the love seat beneath it. We used the insurance money to help pay Erik’s tuition at the Cathedral School. Andy Lacis helped me put up sheet rock to cover the hole. At issue was my slowness. The ceiling had lots of cracks. I’d work a couple of hours, then rush to the office, leaving dust for Anniek to clean up. This went on for months. After Anniek burst into tears, finally showing anger, I finished the job, using Thanksgiving vacation to do it. Anniek created a much more valuable apartment. Eventually we sold it, buying a larger rundown apartment in the building for the same price. Then she began remodeling again.

It required five years to build and test our instrument for the Pioneer mission to Venus, sufficient time for profound issues to arise about changes occurring on our home planet. Those issues drove a dramatic change in our research focus. But before I leave the planetary science era, I should summarize what I learned about the scientific method. My description of the scientific method is simple. You must: 1. Study all available data on the matter, 2. Be very skeptical of your interpretation, 3. Honestly reassess from scratch when new data become available, 4. Not allow your ideology, your preference, to affect your assessment. Adherence to the scientific method is actually quite difficult, especially because of item #4. Professor Van Allen’s requirement of an ‘original proposition’ helped instill skepticism in me, especially when I chose a proposition – an internal Venus heat source – out in left field. I expected new data on Venus would likely disprove my proposition, so it was easy to be skeptical. Along those lines, let’s compare some planets, which will allow me to correct a significant error that I made in my prior book, Storms of My Grandchildren, about the runaway greenhouse effect.

65 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 10.1. Greenhouse warmings of Mars, Earth and Venus are about 5°C, 33°C and 500°C. Chapter 10. Runaway Greenhouse

Mars, Venus and Earth are the Goldilocks planets -- too cold, too hot, and just right. These planets nicely show how the greenhouse effect depends on atmospheric composition. The physics of the greenhouse effect is mainly energy balance: a planet sends back to space, in the form of heat radiation, the same amount of energy that it absorbs from sunlight. The amount of absorbed solar energy is known for each planet – from the Sun’s measured irradiance44 and the planet’s measured albedo, which is the fraction of incident sunlight that the planet reflects away. Absorbed solar energy is the remaining fraction of the incident solar radiation. Radiant energy leaving a surface increases as the surface temperature rises. The radiated energy as a function of the temperature is defined by the Stefan-Boltzmann ‘law’ (physical principle), which was deduced by Josef Stefan in 1879 from laboratory measurements of the Irish physicist John Tyndall and independently derived from thermodynamic theory by Ludwig Boltzmann in 1884. The equation45 expressing this law makes it easy to calculate the planetary surface temperature required to radiate back to space the absorbed solar energy. If the planet has an atmosphere that absorbs heat (infrared) radiation, calculation of the surface temperature is more complex. The atmosphere acts like a blanket – it reduces heat radiation to space. The atmosphere itself radiates heat to space, but the atmosphere transfers a reduced amount of heat, because the atmosphere at altitude is usually colder than the ground, where most solar energy is absorbed. Thus, when more greenhouse (heat absorbing) gas is added to the air, radiation to space is reduced and the planet temporarily is out of energy balance – more energy coming in than going out -- so the planet gradually warms until energy balance is restored. The processes discussed so far constitute ‘radiative transfer’ of energy. Radiative transfer alone is inadequate to describe atmospheric temperature, because atmospheric motions also transfer energy. Heating of the ground, for example, produces hot air, which rises. Convection, this vertical mixing of air and heat, can be included readily in calculations of the vertical temperature profile in the atmosphere. A still more realistic calculation accounts for three-dimensional energy transfer. Solar energy, absorbed more at low latitudes, is carried poleward by winds, and by the ocean on Earth. To handle all that, a global climate model is needed. However, the simple one-dimensional radiation plus convection calculation is sufficient for basic understanding of the greenhouse effect.

66 © 2020 James Edward Hansen. All Rights Reserved. Mars’ atmosphere is so thin that almost all of the heat radiation from the ground goes straight through the atmosphere to space. Accordingly, Mars enjoys almost no greenhouse effect: Mars’ surface is only a few degrees warmer than calculated with the Stefan-Boltzmann law. Specifically, Mars requires a surface temperature of only about minus 50 degrees Celsius (-50°C) in order to radiate back to space the energy that it absorbs from the Sun. The temperature •50°C is about 60 degrees below zero Fahrenheit (•60°F). Earth has more atmosphere than Mars. John Tyndall meticulously measured the radiation properties of many gases.46 He found that the main constituents of Earth’s atmosphere, the diatomic molecules nitrogen (N2) and oxygen (O2), are transparent to visible light and infrared radiation, but the triatomic molecules, water vapor (H2O) and carbon dioxide (CO2), are strong absorbers of infrared radiation. Their triatomic structure results in vibrational energy states that are excited by infrared photons. We will learn more about the remarkable Tyndall later. Earth absorbs 70% of the energy it receives from the Sun. If Earth had no atmosphere, its temperature would need to be only •18°C to radiate that absorbed energy back to space, according to the Stefan-Boltzmann law. In reality, Earth’s average surface temperature is a pleasant +15°C. So Earth’s greenhouse warming is 33°C (almost 60°F). Venus absorbs just 23% of incident sunlight, because of its highly reflective, complete cloud cover. As a result, it requires a planetary radiating temperature of only -43°C to radiate that energy back to space. However, the Venus surface temperature is more than 450°C, hot enough to melt lead! The greenhouse effect on Venus is about 500°C (900°F)! The main reason for the huge greenhouse effect on Venus was revealed by several Soviet Venera spacecraft and the later United States Pioneer Venus mission. The surface pressure on Venus is about 90 bars, which is 90 times the surface atmospheric pressure on Earth, and atmospheric composition is almost entirely CO2. Other constituents, mainly a small amount of water vapor, the sulfuric acid clouds, and sulfur dioxide (SO2), contribute to the greenhouse effect, but CO2 is responsible for most of the greenhouse warming on Venus.47 The Goldilocks planets illustrate weak, moderate and strong greenhouse effects. But how did the planets get to the present situations? What are the implications for future climate on Earth? Can Earth end up like Venus, a lifeless hothouse? Yes, it can – but the runaway greenhouse story I described in Storms of My Grandchildren requires a modification.

Venus’ runaway greenhouse effect reached a terminal state, a ‘baked crust’ greenhouse. How does that work? Venus was doomed to a baked crust and a permanent climatic hell as soon as it lost its ocean. But wait, let’s back up a step first. The crust is the outer layer of a ‘solid’ planet such as Venus or Earth, like the skin on an apple. Continents are tectonic plates, slabs of solid rock, which are mobile, riding on top of the viscous mantle. Most of South and North America, for example, are sliding westward at a rate of about an inch per year, overriding thinner oceanic crust that lies under the Pacific Ocean. Volcanoes and mountain building occur along the forward edges of the continental plates, continually pouring volatile crustal gases, including CO2, into the atmosphere. On a planet with an ocean, the CO2 gets put back into the crust rather quickly – that is, if you consider a few thousand years to be quick, which it is for planets more than four billion years old. CO2 is

67 © 2020 James Edward Hansen. All Rights Reserved. extracted from the air by the weathering process – chemical decomposition of rock, including biological effects. Rainfall is naturally acidic, containing dissolved CO2; plants and animals release acidic compounds and speed weathering in various ways. Streams and rivers carry chemicals to the ocean, ultimately depositing CO2 as limestone on the ocean floor. (Later we 48 will discuss enhanced weathering as a way to speed up removal of CO2 from the air. )

On a planet without an ocean, like the Venus of today, CO2 from volcanoes stays in the air, building up to a huge amount – crustal CO2 is ‘baked’ into the atmosphere, with no mechanism for rapid return to the crust. There is so much CO2 in the air that the surface pressure, 90 times that on Earth, would crush human beings, if they were not already fried to a cinder!

How did Venus lose its ocean? Will Earth lose its ocean? It will, but not soon. The story is pretty straightforward. Our Sun, and the planets orbiting about it, formed 4.6 billion years ago from the gravitational collapse of a swirl of gas, ice and dust in a spiral arm of our Galaxy, the Milky Way. Although all of the planets formed from this material, the inner planets – Mercury, Venus, Earth and Mars – lost most of their gases because of their small planetary masses and proximity to the Sun. Radioactive heat is sufficient for the planetary mantle to behave as a viscous fluid on geologic time scales and release volatile gases, especially from volcanoes. Young Earth, because of its larger mass and greater distance from the Sun, had more water than young Venus. Young Venus had enough water to form an ocean, but lost most of its water through hydrogen escape. Air molecules continually bump into each other, moving faster when the gas is hotter, with the smallest ones gaining the most speed after bumping into heavy molecules. In the upper atmosphere solar ultraviolet radiation continually breaks up (dissociates) molecules. Hydrogen, the lightest atom, moves the fastest, and sometimes, before it recombines with another atom or molecule, it shoots out into space, escaping the planet’s gravity. In this way, a planet loses water, as the oxygen left behind combines with other elements.

How much water did young Venus have? We know that pretty well, based on Pioneer Venus measurements of the amount of the hydrogen isotope , sometimes called “heavy hydrogen.” A normal hydrogen atom has only a proton in its nucleus, but deuterium has a proton and a neutron. So deuterium is about twice as heavy as normal hydrogen. Deuterium cannot escape to space as easily as normal hydrogen, because deuterium is heavier. Pioneer Venus found that the deuterium amount on Venus was about 1 percent of the hydrogen still in the atmosphere. That is a huge enrichment over the initial deuterium on Venus, which was believed to be only 0.005% of total hydrogen (50 parts per million). Based on these data, Mike McElroy and colleagues49 concluded that Venus initially had enough water to form a layer 8 meters thick, if it covered the entire planet. This was a lower limit, because some deuterium also must have escaped. Moreover, the later Galileo mission to Jupiter found that the deuterium proportion of hydrogen on Jupiter was only 25 ppm. Jupiter’s gravitational field is too strong to allow even normal hydrogen to escape, so 25 ppm is a better estimate of primordial deuterium abundance in the solar nebulae from which the planets formed. Therefore McElroy’s estimate of the initial water on Venus can be increased to at least 16 meters.

68 © 2020 James Edward Hansen. All Rights Reserved. Sixteen meters of water is only about half of 1 percent of the amount of water on Earth today, but it is still a lot of water to be lost via hydrogen escape. That much water could not have escaped if the Venus atmosphere had a “cold trap” like the one on Earth. The upper troposphere on Earth, at a height of about 10 miles, is so cold that it ‘wrings out’ almost all the water. When air mixes upward from Earth’s lower atmosphere it must pass through this cold trap. The upwelling air then becomes so dry that it delivers very little water to the outer fringes of the atmosphere. Water cannot escape from Earth today, at least not a significant amount of water.

Yet Venus’ ocean did escape, we know from its deuterium amount. How could that be, when a cold trap was expected to exist on Venus?50,51 Andy Ingersoll52 proposed a solution to this conundrum: a runaway greenhouse. He argued that if a planet were warm enough for water to be a major constituent of the atmosphere, the greenhouse effect would force continuous evaporation of surface water, and convection would carry water vapor to great altitude, leading to more water being available for dissociation by ultraviolet light in the upper atmosphere. In effect, Ingersoll said if the climate forcing is large enough, so the atmospheric temperature is high enough, so the water vapor mixing ratio is large enough, the resulting blocking of infrared heat transport will force a pumping of water vapor into the upper atmosphere, where the hydrogen can escape. Sounds like a Rube Goldberg machine? Not really; it’s a simple concept, but it must be tested with realistic calculations. Ingersoll assumed that water vapor absorbs equally at all wavelengths, but actually absorption varies a lot with wavelength, including ‘windows,’ spectral regions in which the gas is transparent or almost transpaent. Also, we must calculate the upward transport of water vapor via a realistic description of moist convection in a global climate model. Such calculations,53 shown in Figure 10.2, confirm the essence of Ingersoll’s thesis. To explain this figure, it helps to first define the concept of a climate forcing (a concept we will need later in order to interpret climate change on Earth).

A climate forcing is an imposed perturbation of a planet’s energy balance. It is measured in watts per square meter (W/m2) averaged over the planet. Let’s consider a forcing of +4 W/m2, which is the climate forcing caused by doubling the amount of CO2 in the air. The same magnitude of forcing occurs if the brightness of the Sun increases by about 2 percent.54 In either case, the response to this forcing – this imposed planetary energy imbalance – will be a warming of the planet until energy balance is restored.

The climate forcing due to any CO2 change can be calculated accurately because the absorption 2 by CO2 is accurately known at all wavelengths. A forcing of approximately 4 W/m continues to occur for each CO2 doubling over a remarkably large range of CO2.

“How can that be?” you might ask. “Doesn’t the CO2 absorption band get ‘saturated,’ so heat radiation emitted from the ground is not able to escape directly to space without being absorbed. Adding still more CO2, thus making the “blanket” thicker, should not have much effect.” You may wish to skip the technical explanation for why that is not true, but if you are willing to take the trouble and come to understand Fig. 10.2, you will join an exclusive club to which even most Earth scientists do not belong. You will understand the greenhouse effect. If you are not interested in that, you can jump ahead to “Will Earth have a runaway, baked-crust greenhouse?”

69 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 10.2. Global mean temperature profile for successive quadruplings (or halving) of CO2 amount.

Radiation from Earth to space is still reduced by further increase in the CO2 amount, even though absorption of radiation from the ground at a given wavelength is already 100 percent. Radiation to space is a function mainly of the temperature at the level in the atmosphere at which the photons of heat radiation, which are emitted in all directions, are able to escape to space. The level of emission to space occurs where the opacity (the opaqueness), as measured from the top of the atmosphere downward, is of order unity. That simply means that the opacity is such that a photon is close enough to the top of the atmosphere that it has a good chance of escaping without being absorbed. Now we must explain only one more thing about heat radiation. Absorption by gases, mainly water vapor and carbon dioxide, occurs across the entire spectrum of Earth’s infrared (heat) radiation, but absorption is not uniform across this wavelength spectrum. Therefore radiation to space arises from all altitudes in the atmosphere. On average the altitude from which the energy emerges is about 5.5 km. Not surprisingly, the temperature at this altitude is close to -18°C, the temperature that a solid body requires in order to radiate the energy that Earth absorbs from the Sun. The temperature difference between this altitude and the surface is about 33°C, which is the present greenhouse effect on Earth.

Now we can turn to Fig. 10.2. The Sun causes maximum heating at Earth’s surface, because of the atmosphere’s transparency to sunlight. Because of the blanketing of heat radiation by greenhouse gases, convection as well as radiation carries the energy upward to a level at which the energy can be radiated to space. Convection, rising and sinking air, establishes a temperature gradient in Earth’s atmosphere, with temperature falling off with height on average by about 6°C per kilometer of altitude. The heavy black curve in Figure 10.2 is the temperature profile produced by the climate model 55 for contemporary atmospheric CO2 amount. Note the minimum at pressure level about 100 mb; that minimum is the ‘cold trap.’ The other curves show the temperature profile after the CO2 amount is repeatedly quadrupled (or halved). After six doublings (three quadruplings), to a CO2 amount 64 times greater than the contemporary amount, the cold trap is eliminated. For still larger CO2 amounts, the temperature at altitude continues to rise, allowing even more water vapor to be pumped to the upper atmosphere, where hydrogen can escape to space. 70 © 2020 James Edward Hansen. All Rights Reserved. Burning fossil fuels will not result in such large CO2 amounts, because the weathering process extracts atmospheric CO2 and deposits it as limestone on the ocean floor. On the other hand, atmospheric temperature high enough to drive hydrogen escape is readily achieved for a planet as close to the Sun as Venus is. Hydrogen escape and a runaway greenhouse will also occur on Earth, if we wait long enough for the Sun to become sufficiently luminous.

Consider the case of 10 CO2 doublings, i.e., a CO2 increase by a factor of 1024. Ten doublings yields a climate forcing of about 40 W/m2, which produces a temperature profile that would carry water vapor to the upper reaches of the atmosphere. Compare that 40 W/m2 forcing to the climate forcing that occurs if we move an Earth-like planet, that is, a planet with an ocean, from Earth’s orbit to the orbit of Venus. Solar irradiance at that distance from the Sun is twice as great as at Earth. Solar heating of Earth, if moved to the Venus orbit, would increase from its present 240 W/m2 to 480 W/m2, thus constituting a climate forcing of 240 W/m2 relative to the climate on Earth today. When Venus had an ocean, that planet must have been more Earth-like than today, with water clouds, but with no stratospheric cold trap. Water vapor was pumped efficiently to the upper atmosphere, where hydrogen could escape to space. Thus the modest ocean on Venus was lost. Once the ocean was gone, the CO2 belching from volcanoes stayed in the atmosphere and Venus was on its way to being a permanent hothouse, a baked-crust planet.

Will Earth have a runaway, baked-crust greenhouse? Yes, but not soon. Today nuclear fusion in the Sun’s core is converting hydrogen to helium, with the release of energy that provides the Sun’s luminosity. The luminosity is increasing now at a rate of about 10 percent per billion years.56 As the Sun, an ordinary ‘main sequence’ star, exhausts the hydrogen in its core, nuclear reactions will continue, first with hydrogen fusion in the Sun’s outer layers and then via fusion of helium into larger elements in the Sun’s core. Eventually the Sun will expand into its Red Giant phase, engulfing Earth about 5 billion years in the future. Before then, perhaps as soon as one billion years from now, Earth will lose its ocean and experience a runaway, baked crust greenhouse. However, a billion years is far enough in the future that you do not need to worry about it. Before then, humanity, if it does not do itself in sooner, should have the capability to emigrate to a more hospitable place. There is a milder runaway greenhouse effect possible on time scales that today’s young people should be concerned about, because it does pose an existential threat to humanity. I’ll call this the ‘existential threat’ or ET runaway greenhouse.

The ET runaway greenhouse is a possible future for humanity if we should be so foolish to continue much longer to ignore the climate threat posed by burning most of our fossil fuels. In the ET runaway greenhouse scenario, we allow high fossil fuel emissions to continue to the point that rapid disintegration of the Antarctic and ice sheets begins, causing a rapid sea level rise of many meters and the loss of all coastal cities. Perhaps the most crucial issue (to be addressed in later chapters) is the need to understand just how “rapid” sea level change can be, and what we can do to alter the course that our planet is on. Loss of coastal cities would occur simultaneous with low latitudes becoming unreasonably hot and humid. Global emigration pressures could become so great that global governance would break down and the planet would descend into chaos. That is the ET runaway greenhouse.

71 © 2020 James Edward Hansen. All Rights Reserved. Let me be clear. I am optimistic that we will be able to avoid the ET runaway greenhouse. I believe that the United States and China will realize that all humanity is in the same boat and we need to cooperate. We can, together, use our technological prowess to pull back from the brink. But pulling back from the brink will not happen without effort. It is not enough to demand that governments address global climate change; none of the political parties are advocating an approach that would actually work. It is necessary that the public, especially young people, understand the actions that are needed. That is my purpose in writing this book.

What was the error in Storms of My Grandchildren? In that book, extraterrestrial visitors to Earth in 2525 find a lifeless planet. Such an outcome is conceivable, given the potential chaos accompanying an ET runaway greenhouse. The particular flaw in Storms is that the visitors witnessed boiling tropical oceans, a physical state not possible on a 500-year time scale. That sentence should be eliminated.

Planetary science became my passion in the first half of the 1970s, while my interest in becoming an astronaut waned. I spoke with Brian O’Leary, who applied, successfully, to the astronaut selection process in 1967 – precisely the class that, at the last moment, I had decided not to apply for. Brian resigned one year after being accepted into the astronaut program. His primary reason for giving up his astronaut ambition was realization that it was not practical to be an astronaut and at the same time be a fulltime, practicing scientist. I was still early in my career path aimed at becoming a scientist, and still needed to catch up. People like Jim Pollack had a broader understanding than I had. I believed I soon would be caught up so that Anniek and I could start living like normal people, and she believed me. I did not foresee the emergence of more riveting issues, that would emerge in three steps, the first a seemingly innocuous involvement in weather prediction.

72 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 11.1. Dr. Robert Jastrow Chapter 11. Weather Prediction Dr. Jastrow was brilliant. If he had not been eclipsed by Carl Sagan, he would have been famous. Jastrow’s television series on space science in the 1960s was widely viewed and his book57 based on those programs, Red Giants and White Dwarfs, was a popular masterpiece on the evolution of stars, planets and life. However, in the 1970s Jastrow’s appearances as Johnny Carson’s guest on the Tonight show were largely displaced by Carl Sagan. Jastrow’s management style at GISS was imperial, at least during the period I knew him, which began in early 1967. Joop Hovenier, during his first visit to GISS, remarked: “It’s incredible, that man rules by fear!” That was after Joop sat in Jastrow’s outer office waiting to see him and observed the interactions between Dr. Jastrow and the people working for him. Yet Jastrow’s intellect and drive were attractive. He brought in topflight scientists. Jastrow was good at stirring the intellectual pot and focusing discussion on specific objectives. The topic of prime interest to him in the early and middle 1970s was how weather forecasts might be improved with the help of satellite observations. I attended several of the ‘weather’ meetings. Participants included meteorologists Jule Charney of MIT and Vern Suomi of the University of Wisconsin. Charney was a leading theoretician in atmospheric dynamics and led the first successful numerical weather prediction.58 Suomi, known as the father of satellite meteorology, had the second science instrument on a United States satellite, after Van Allen’s Geiger counter. Suomi pioneered the spin-scan imaging technique59 that we adopted for our Pioneer Venus imaging polarimeter.

The most useful information for improving forecasts would be measurements of wind speeds at different altitudes in the atmosphere. That would allow us to see how the atmosphere was circulating, how the weather systems were moving. Unfortunately, it is not easy to see the wind. Suomi’s idea was to infer wind speeds by observing movement of clouds. The utility of this idea was limited by the fact that clouds are not present everywhere, upper clouds shield lower clouds from view, and some clouds, such as those locked over mountains, do not move with the wind. Charney had a different idea, which was complementary to Suomi’s, because Charney’s method would work best in cloud-free regions. Charney’s proposal was based on use of atmospheric temperature profiles measured by . Temperature profiles are obtained by measuring the infrared radiation emerging at the top of the atmosphere at several different wavelengths. 73 © 2020 James Edward Hansen. All Rights Reserved. Radiation in the center of a strong CO2 absorption band arises from high in the atmosphere, while radiation from successively weaker bands arises from deeper and deeper in the atmosphere. Radiation at wavelengths with no gas absorption arises from the ground. The magnitude of the radiation provides a measure of the temperature at each of these levels. Charney’s proposal was to insert observed temperatures into a weather model, providing correct initial conditions for model simulations of future weather. Correct temperatures would also help the model calculate realistic winds, which are driven by temperature and pressure gradients. An obstacle to Charney’s plan was that satellite temperature data referred to thick atmospheric layers and included substantial measurement error. Accuracy could be improved, however, by comparing satellite data with radiosonde (balloon) data. Satellite algorithms were thus ‘trained’ by radiosonde ‘truth’ at the radiosonde station locations to give better satellite results all around the world, but radiosondes had their own errors, so it was a lot of work to get the best result. Intellectual fervor generated competition, as is common in science. One of Dr. Jastrow’s secretaries once ran down to my office concerned that Charney was having a heart attack. Charney was at a desk in Jastrow’s outer office, on the phone with Jastrow, who was working at home, as was often the case. Jule Charney was a warm, congenial person, but in this instance he was coughing and highly agitated. He loudly accused Jastrow of stealing his ideas in a paper on satellite-aided forecasting that Jastrow had submitted for publication. Those difficulties were soon smoothed out. However, the task of putting these ideas into practice, of testing them with real global observations, was a huge job, one that would take many years. It was not a job that Charney or Jastrow would want to manage on a day-to-day basis.

Milt Halem was Jastrow’s lieutenant managing the weather prediction project. The project was challenging because of the still primitive status of computers, weather models, satellite instruments and satellite data analyses. The project had to deal with all of these facets, with a team that included about 60 people on the support services contractor staff. Milt was a tough taskmaster, yet it was hard not to like him. With his roundish, dimpled face and curly hair, he was like a big teddy bear. Milt was loyal to Jastrow, accepting ambitious targets and working at them harder than anyone. He was an optimist and sometimes jovial, so underlings did not mind working for him, even though he was demanding. The atmosphere could be tense when Dr. Jastrow got involved. In one exchange, Dr. Jastrow berated a young scientist for being slow and punctuated his demand by firing a blackboard eraser that hit the retreating scientist squarely in the buttocks. Dr. Jastrow frequently played handball in the Columbia University gym – that practice must have been good for his aim. Development of a weather model became the principal activity at GISS. Charney recommended that GISS start with the UCLA two-layer weather model developed by Akio Arakawa and Yale Mintz. Arakawa was a mathematical wizard who devised a stable numerical scheme to solve the equations of atmospheric motion in a way that properly conserved mass, energy and momentum, while including essential physics such as solar heating of the atmosphere and ground. Arakawa was a genius, but his English was almost unintelligible. When he gave a talk at a GISS conference, the stenographer wrote hama-hama-hama – she could not understand a word he was saying. The main function of Prof. Mintz seemed to be to translate and interpret Arakawa.

74 © 2020 James Edward Hansen. All Rights Reserved. The UCLA model had to be modified for our intended application. The atmosphere needed to be divided into many layers, so that the model could usefully incorporate satellite measurements of the atmosphere’s vertical temperature profile. The model also should incorporate accurate physics for the heating of the atmosphere and surface. Ozone and water vapor, for example, absorb sunlight. Ozone absorption heats Earth’s stratosphere, at heights 15-30 miles, while water vapor absorbs sunlight in the troposphere, the lowest several miles of the atmosphere. I was the obvious person at GISS to provide this physics, because the calculations needed to include the effect of light scattering by clouds and aerosols. Surely, that was part of the reason that Dr. Jastrow sought a promotion for me just 18 months after I was hired.

The promotion package was in my personnel folder, which was given to me on the day that I left NASA in 2013. The folder contained records of my hiring, promotions, security clearances, and so on, including a 1 October 1973 memo from Dr. Jastrow to George Pieper, Director of Space Sciences recommending that I be promoted to GS-14 (government’s equivalent of associate professor) from the GS-13 level. I describe this promotion procedure as an example of how a still-young NASA worked. Later I will contrast this with NASA’s civil service system as the agency aged. The sclerosis that developed extends throughout our government. It is fixable, but it is not being addressed. There is another reason to be explicit. I will contrast evaluation at this point with that later in my career, after I began to question NASA management priorities and programs. Issues will include not only efficient use of taxpayer dollars, but acquisition of information critical for understanding the future of our planet and the well-being of young people. A lot had changed in 18 months! Now Jastrow said of me “…along with Drs. Thaddeus and Halem he has shouldered more management responsibilities than any other civil service scientist at GISS…”. Also, thanks to our Pioneer Venus and other planetary funding, my group had become one of the main reasons for NASA support of the Goddard Institute. Jastrow’s memo requesting my promotion included laudatory evaluations, e.g., from Richard Goody of Harvard (“Hansen’s work is highly reliable and very solid. When he does something, people believe it, which is not true of a lot of others. He is about the best man in the field in the world, now that van de Hulst is not actively publishing.”) Jastrow noted that “Goody’s closing endorsement of Hansen as the best in the international community is especially significant because Goody is the most critical and caustic scientific personality in this field.” Inflation of evaluations is standard practice in promotion packages. In reality, Hovenier was the best-grounded young researcher in polarized light scattering, we would both soon be eclipsed by Michael Mishchenko, and none of us could hold a candle to van de Hulst.

Light scattering in Planetary Atmospheres, the paper I was working on at that time, turned out to be my last paper in atmospheric radiation. I did not intend to abandon the field – I thought that I would work together with Andy Lacis on atmospheric radiation. But I was pulled by a siren in a different direction. It was an unfamiliar, dangerous route. We could easily crash on the rocks, and it might be difficult to turn back, if we set sail in that direction.

75 © 2020 James Edward Hansen. All Rights Reserved. Chapter 12. The Ozone Connection

Paul Crutzen and Harold Johnston pointed out that supersonic aircraft proposed in the early 1970s might reduce stratospheric ozone via chemical reactions initiated by nitrogen oxides in aircraft exhaust.60 Ozone absorbs ultraviolet sunlight, preventing the most energetic ultraviolet rays from reaching the ground, where they would be damaging to humans and other life. Other objections to supersonic transports (SSTs) included their noise pollution. Battles ensued in the U.S. Congress. Planetary scientists were involved, because atmospheric chemistry studies of other planets provided a broad understanding and a powerful atmospheric simulation capability. Detailed modeling61 confirmed the concerns of Crutzen and Johnston, although effects of SSTs on ozone were found to be less than initially feared. The U.S. decision against commercial development of SSTs was based mainly on concerns about their commercial viability.

Mario Molina and Sherry Rowland,62 however, soon identified a serious threat to ozone: chlorine (Cl) released in the stratosphere by photodissociation of chlorofluorocarbons (CFCs). Chemical reaction of Cl with ozone (O3) results in conversion of ozone to oxygen (O2), thus causing a depletion of stratospheric ozone.63 CFCs were a serious threat to the ozone layer. Consequences appeared sooner than expected, with the discovery of the Antarctic “ozone hole,” a massive depletion of stratospheric ozone around the South Pole that recurred each spring. proposed that chemical reactions on ice crystals on polar stratospheric clouds sped the conversion of ozone to oxygen, and she led an expedition to Antarctica that confirmed her interpretation. The scientific community did an exceptional job of guiding assessment of the CFC threat and communicating the implications to the public and policymakers. The Montreal Protocol and CFC phasedown did not just happen – a large effort was required. The research community deserves much of the credit for that success, and Crutzen, Molina and Rowland were deservedly awarded a Nobel Prize in Chemistry for their contributions. Solomon was awarded the Crafoord Prize, the Geosciences equivalent of the Nobel award. I describe the science community’s guidance regarding ozone depletion because later I must contrast it with much less successful scientific guidance in the case of climate change. Blame for failure of governments to stem climate change cannot be placed solely on politicians and the fossil fuel industry. We scientists bear a large portion of the responsibility.

The planetary science community included researchers who were among the most expert on Earth’s stratosphere, including Tom Donahue and Don Hunten, who co-chaired Pioneer Venus meetings. They and a small group of the leading researchers exerted extraordinary influence in shaping the research program that was needed to provide good policy advice to governments. An initial issue was the choice of government agency responsible for the ozone science program. Scientists should let policymakers decide that, right? Not according to Hunten and Donahue! That issue came up earlier: who should manage investigation of the SST effect on stratospheric ozone? The Department of Transportation (DOT) was entrusted with that research program.

76 © 2020 James Edward Hansen. All Rights Reserved.

Sherry Rowland, Mario Molina, Paul Crutzen and Susan Solomon

Was the fox being asked to guard the hen house? Like putting the Energy Department in charge of a CO2 and climate program? That management debacle will be discussed later! Hunten, Donahue, and others argued forcefully that an independent science agency should be given responsibility for stratospheric research. An ongoing research program could provide knowledge useful to assess the SST and CFC issues, and the knowledge could help head off other potential problems before they became major headaches.

These scientists preferred that the stratospheric science program be located in NASA. Some official accounts credit agency bureaucrats with affecting the congressional decision, but that is not how it worked according to Rasool, who was then chief scientist at NASA Headquarters. Congress people and their staffers like to speak directly to scientists who know what they are talking about. The advice they got was to assign the program to NASA. In June 1975, Congress passed legislation directing NASA to conduct a comprehensive stratospheric research program. I was fortunate to attend some of the early meetings of the research leaders. Like in my first physics courses, I sat in the back row and tried to be inconspicuous. Most issues concerned atmospheric chemistry. Discussion was collegial. Mike McElroy was in his element in the repartee, once quipping “age before beauty” as he deferred to Tom Donahue. A big workshop was held in Washington, DC, giving all scientists a chance to offer suggestions about the nature of the budding program. I summoned up the courage to proffer comments about the need to monitor stratospheric aerosols, because aerosols affect atmospheric chemistry, and also a comment about the value of comparing Earth’s atmosphere with that of other planets.

Paul Crutzen, then manager of atmospheric chemistry at NCAR, nearly bit my head off. Perhaps he thought that I was suggesting that stratospheric research funding be used to support research on other planets. I was not about to talk back to a legend, even if I had the debating tools, which I did not. I was still smarting at Crutzen’s sharp rebuke on the way home. The issue relates to a basic problem affecting science. Disciplines tend to become specialized, each in its own silo. One way to combat isolation is housing different disciplines in proximity. Solution to specialization, however, also requires housing multiple disciplines in the same brain.

77 © 2020 James Edward Hansen. All Rights Reserved. Planetary science is a small field. Planetary scientists are often renegades, living in physics or astronomy departments. That is an advantage. It helps planetary scientists acquire a broad interdisciplinary background, which is useful for Earth studies. I decided to write a proposal to try to get our group into stratospheric research. Discussions had focused on chemistry, for which we had no background. But there were other interesting issues. What about the effect of ozone change on climate? That is largely a radiation problem, but not simple, because ozone effects depend on the altitude of the ozone change.64 Atmospheric dynamics, as well as chemistry, would be needed for that problem, because atmospheric motions affect how ozone-depleted air gets spread around the planet. So we would need a three-dimensional model to study the problem. However, if we look at Earth from a planetary perspective, at the large scales of Earth’s atmospheric circulation, it seemed to me that it may be sufficient for the model to have coarse spatial resolution.

Andy Lacis and I had already worked on the GISS weather model for a few years. We were co-authors on a paper65 describing the weather model and we wrote our own paper66 describing an efficient way to calculate atmospheric radiation in global models. The weather model was cumbersome and slow, because its spatial resolution was the finest that our computer could handle. The decade-old GISS computer, which was still the IBM 360/95 purchased in 1967, allowed resolution only as fine as about 400 km (about 250 miles). In other words, the model divided the world up into boxes with the area of the state of Georgia. Georgia-size resolution is coarse for a weather model, but too fine for what I had in mind. My suspicion was that ozone depletion might be usefully addressed with a coarser resolution. The model’s computing time is inversely proportional to the cube of the model resolution.67 So if the resolution is made 800 km, instead of 400 km, the computing is 2×2×2 = 8 times faster. With a resolution of 1200 km, the model is 27 times faster. My opinion on this would not mean much. The issue concerns atmospheric dynamics. What scale of atmospheric motion is essential for global transport of atmospheric ozone? Fortunately, Prof. Peter Stone of MIT, a world expert in atmospheric dynamics, agreed that coarse resolution may be sufficient for many purposes. And he was eager to work with us in developing a model.

Ichtiaque Rasool was the point person at NASA Headquarters for stratospheric research when Congress assigned the program to NASA in 1975. Given that the science was focused on atmospheric chemistry, how could I persuade Rasool that we had something to offer? Ozone change would not only alter the amount of UV radiation reaching Earth’s surface, it would also affect Earth’s energy balance. A planet’s energy balance is determined by radiation: the amount of solar radiation absorbed by the planet and the amount of heat radiation emitted to space. So I could argue that it was important to do the radiation calculations accurately.

Ozone’s effect on atmospheric radiation is complicated. Ozone (O3) is a triatomic molecule, like CO2 and H2O, so it absorbs infrared (heat) radiation. In other words, it is a greenhouse gas. However, ozone also absorbs sunlight, mainly in the stratosphere. Most sunlight reaches Earth’s surface, causing a maximum temperature at the ground. Temperature decreases with height in the lower atmosphere, the troposphere, up to a height of about 10 miles (about 15 km). Above

78 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 12.1. Chart used for 1975 research proposal to Rasool and Hunten. that height, because of ozone absorption, temperature increases to a maximum at the top of the stratosphere, at a height of about 30 miles (about 50 km). So if humans alter ozone, they can change the entire temperature structure of the atmosphere. This was an argument why NASA needed radiation experts in its stratospheric research program.

I flew to Washington on the 6 AM Shuttle, earlier than necessary for a late morning meeting with Rasool, but I wanted to be sure to avoid air traffic delays that frequently affected LaGuardia and National airports. The extra time was useful. I thought of a good introductory chart. Those were days when scientists carried felt-tipped pens and transparent plastic pages on which we could write, making ‘viewgraphs’ that could be projected on a screen or wall. At the airport I drew a diagram, three ovals labeled Radiation, Dynamics and Chemistry, connected by arrows. The chart got me in trouble, because I put Radiation at the top. Rasool was amused by this. He called in a Headquarters colleague who was passing the conference room. “Look, this is interesting, Jim thinks that radiation is the most important part of the ozone problem!” Rasool was trying to have a good time in the dull Headquarters job that he had got himself into. But he would not make a funding decision without expert advice. He got Don Hunten on the speaker-phone. I felt tense as I haltingly tried to explain what I was proposing. Hunten, who tended to be caustic and critical, was silent for a long time.

“Sounds like a good plan,” a gruff voice came from the box on Rasool’s desk. Whew! Hunten elaborated. He said that there was only enough money the first year for high priority tasks, such as measurements of chemical reaction rates. However, funding in the next year was likely. Hunten provided a strong piece of advice; we should seek a talented young chemist for our team. He said Mike McElroy had cornered the market, he had most of the best post-docs. When I got back to New York, I called McElroy. He expressed interest in collaboration and said that we might have a chance with one of his best proteges, Yuk Ling Yung, who was about ready to strike out on his own. We agreed that Yung should visit GISS and give a seminar.

Yuk Ling Yung’s enthusiasm was infectious. He paced back and forth in front of the blackboard. Phrases and sentences came out in chunks, staccato, as he explained how and why atmospheric gases are changing. Yuk revered his mentor, describing McElroy’s ‘red book,’ a review of the state of knowledge of atmospheric chemistry, as “the bible.”

79 © 2020 James Edward Hansen. All Rights Reserved. We needed to get moving, Yuk said. There was exciting research to do. The atmosphere of our home planet was changing. We better understand it, because there are likely to be consequences. A planet that is changing is the most interesting planet to investigate.

CO2 was not the only greenhouse gas humans were changing. Veerabhadran Ramanathan had shown68 that the greenhouse effect of human-made CFCs was significant. Surely other gases were also changing, even though measurements had not been made yet. Hunten was right. Yung’s expertise in chemistry complemented ours in radiation. We decided to work on a paper together. He would discuss what gases were likely to be changing, and we would calculate the potential greenhouse effect of each gas.

We soon focused on nitrous oxide (N2O) and methane (CH4), because we knew they had strong absorption bands that would make them effective greenhouse gases. Yuk argued that N2O must be increasing because of increasing use of nitrogenous fertilizers, and CH4 should also be increasing because of agricultural sources, landfills and leakage in fossil fuel mining.

The climate effect of N2O and CH4 was overlooked by the scientific community. The World Meteorological Organization (WMO) issued a major report69 stating categorically that “minor constituents like N2O, CH4, etc. are present in such small concentration that their direct effects are negligible” and they “can have only an indirect effect on the energy budget of the planet (through participating in the photochemistry of ozone or the production of particulate matter).” We were confident in our calculations and certain that the WMO report was wrong. Our paper70 was the lead article in the 12 November 1976 issue of Science. The topic quickly grew in importance when measurements of N2O and CH4 became available. Earth, it became clear, was not only the most important planet, because it harbored life, but also the most interesting. My priorities changed rapidly. We needed a climate model to help understand changes occurring on Earth, but as yet we had no funding to build a model.

That’s where Kiyoshi Kawabata came in. We hired Kiyoshi in 1973 to work on planetary research. Kiyoshi had worked with Prof. Ueno on radiation problems, and he happily jumped into calculations to investigate aerosols and clouds on Venus. However, when I failed to get immediate funding for modeling, we needed a ‘volunteer’ to work on the weather model, so we could experiment with coarser resolutions. Kiyoshi was the willing victim. It took a few months, but he got the weather model to work with alternative resolutions. To our delight, 1000 kilometer resolution produced realistic atmospheric circulation. Of course, Akio Arakawa, architect of the UCLA weather model deserved credit for his design of the numerical schemes that conserved important physical quantities at all resolutions. Successful simulation at a coarse resolution helped us write a good proposal. The coarse resolution model was fast enough that we could incorporate chemistry and accurate radiation physics into it. That allowed us to investigate problems including interactions among different parts of the climate system, as suggested by the diagram that I had shown in Rasool’s office.

Yuk was the other critical element. We had potential to form a formidable, internationally recognized group. Yuk was ticketed to be a leader in atmospheric chemistry, Peter Stone was already an authority in dynamics, and we had in-house radiation expertise.

80 © 2020 James Edward Hansen. All Rights Reserved. I presented the situation to Dr. Jastrow. He understood the potential. We had to offer Yuk a civil service staff position to attract him. Dr. Jastrow agreed to have dinner with Yuk and me, to help sell Yuk on the idea. On the day of our dinner, Dr. Jastrow played handball, but said that he would meet us at the restaurant, the Moon Palace, across Broadway from GISS. It was awkward. Yuk and I sipped green tea, assuming that Dr. Jastrow was delayed. Finally, we realized that he was not going to show up. Yuk and I ate by ourselves. I suppose it was unlikely we could have captured Yuk anyhow, or at least not kept him for long. He accepted a tenure-track position at the California Institute of Technology the next year. So, we would collaborate with Yuk and with McElroy, but we did not have an in-house atmospheric chemist.

Nevertheless, the die had been cast. My priority became climate modeling. It would be a struggle to find support. NASA was not lavishing support on GISS the way they had in the early days of the space program, when Headquarters provided funding for a large number of international research leaders to work at GISS. The stratospheric research program provided a modest amount of funding. My group’s main support, however, was from the planetary program. The Pioneer Venus program was ramping up. We made frequent trips to California, where our polarimeter for the Pioneer Venus mission was being built. Larry Travis gradually took over most Pioneer Venus duties, but it was difficult to make much progress in climate modeling, given our small number of people, each with multiple obligations. Just then, an explosion occurred. Sometimes, amidst falling debris and embers, new opportunities arise. So it was with the NASA weather and climate eruption.

81 © 2020 James Edward Hansen. All Rights Reserved.

Dr. Robert S. Cooper Chapter 13. NASA’s Weather & Climate Eruption

Archeology of the eruption may be of interest, but I have not dug into the origins. The eruption occurred when the long-time Director of Goddard Space Flight Center, Dr. John S. Clark, was replaced by Dr. Robert S. Cooper in 1976. Dr. Clark was a kind, sleepy-type director. Occasionally he stopped by the Goddard Institute in New York (GISS) and listened to presentations on our research by Dr. Jastrow and principal scientists. Dr. Clark asked only softball questions. His visits were not threatening. Dr. Cooper was different. A large man, with heavy lips and rings under his eyes, Dr. Cooper was engaged, with a commanding presence. He was an engineer71, with a broad perspective on the potential of space technology. He came to Goddard72 from the Department of Defense, where he returned to become Director of DARPA (Defense Advanced Research Projects Agency), with expertise on the Stealth Bomber and “Star Wars,” the Reagan Administration’s Strategic Defense Initiative, a ground- and space-based plan to protect the U.S. from attack by nuclear missiles. Dr. Cooper’s special interest at Goddard was lasers in space and super-computers, and he worked to infuse these technologies into the NASA space program. Cooper saw great promise for these technologies to improve predictive capabilities for weather and climate change. He devoted several hundred civil service positions, both scientists and engineers, toward that objective. Conceivably the Goddard shakeup was a product of his singular active mind – but it is likely that higher levels of government saw merits in bringing cutting-edge DoD technology into NASA.

The seismic impact of Cooper on Goddard rattled the walls of the Goddard Institute. Cooper wanted the new weather and climate initiative to be on the Goddard home campus, in Maryland. Thus he made an early decision to move Halem’s weather prediction project to Greenbelt. Halem’s move was not a big deal to Goddard, which had about 3,000 civil servants and 10,000 employees in total, but it was a big deal to GISS. The 60 contractor positions devoted to Halem’s project made up more than half of the GISS contractor staff. Moreover, the weather project paid some of the GISS overhead costs and justified other NASA sources of institutional support. The Halem weather modeling project would also take one of the two GISS computers. Jastrow wanted the newer computer to stay at GISS, but that computer had been purchased by the weather project. Jastrow lost that battle. The newer computer was trucked to Goddard.

82 © 2020 James Edward Hansen. All Rights Reserved. GISS was stuck with the decade-old IBM 360/95, a relic of a discontinued computer series. It was an albatross. It required 24/7 baby-sitting by IBM CEs because of its continual breakdowns. The annual maintenance contract with IBM was approaching $1M per year.

This situation was not stable. Loss of the weather modeling project raised the question of whether the expense of maintaining GISS in New York was justified. Two GISS programs could stand up to critical academic review: Thaddeus’ astronomy program and my planetary program. Two other budding but unproven efforts were my global modeling project based on stratospheric research funding and Jastrow’s earth resources project in which several people were exploring potential applications of Landsat multicolor images. A few GSFC scientists objected to the privileged position of GISS, as we resided essentially on a university campus. Norman Ness, a member of the National Academy of Sciences, was vocal in his belief that GISS should be moved to Greenbelt. Goddard management at times likely preferred that outcome, but Jastrow had support at NASA Headquarters, and he was a potent, articulate fighter. However, with the huge transfer of people and funding to Greenbelt, it was clear that Jastrow had to do something to shore up GISS.

Dr. Jastrow had a plan, when he took me along for a meeting with Dr. Cooper at Goddard. Jastrow’s proposal was that the climate model that I had begun to develop be converted to run on supercomputers, the new ‘vector processors’ at the Lawrence Livermore National Laboratory. Livermore, Cooper’s location before he came to Goddard, was established to advance nuclear weapons technology. Livermore needed top-of-the-line computers for its programs. Thus the Laboratory drove development of increasingly powerful machines by the computer industry. Cooper liked Jastrow’s proposition. We could start by reprogramming our climate model to run on Livermore supercomputers, with the expectation that Goddard would acquire such computers. On the plane returning to New York, Jastrow told me I could pick five of Halem’s programmers for the Livermore supercomputer project. Halem would be furious, but Jastrow was the director, and his bargain with Cooper cut off any avenue for Halem to object.

Gary Russell was the prize. Gary is a genius. His Ph. D. is in mathematics, but he understood the physics of the model better than any other programmer. He could make wholesale changes, introducing physics that was needed to convert it from a weather model into a climate model. Several of us got security clearances to go to Livermore to learn about their supercomputers. Those computers churn out calculations fast, but they require special programming. So a lot of time is spent on technical issues and glitches, rather than on the physics of the climate system. Therefore, I divided the five programmers into two groups. One group of four programmers worked on reprogramming subroutines of our climate model to run on a supercomputer. They could continually provide numbers, for example, subroutine X now runs 9.2 times faster on the Livermore supercomputer than on the GISS 360/95, thus keeping Jastrow and Cooper happy. The other “group” was Gary. Gary and I never returned to Livermore. We worked on the physics of the climate model, programmed in a stable computing language. Gary had a good view of the entire model and could clean up the messy programming of the weather model.

83 © 2020 James Edward Hansen. All Rights Reserved. Gary added in-line diagnostics, so we could see results while the model was running. He then began to add new physics, calculating quantities such as ocean temperature, sea ice cover, and soil moisture, rather than specifying these as fixed boundary conditions.

The climate model worked. The model produced the major features of the atmospheric circulation – rising air in the tropics and descending air that causes the dry subtropics, the west- to-east jet streams, and high and low pressure systems – even with our coarse resolution. The U.S., for example, was covered by only 10 gridboxes, each with about the area of Texas. I was not trying to compete with the big modeling groups, which always pushed model resolution as fine as computers would allow. I wanted resolution as coarse as we could get away with, while still producing the most essential features of the atmospheric circulation. Our model was very imperfect, because we made big simplifications as well as coarse resolution. Crucial effects, such as the transfer of heat by the ocean, were not included in our initial model. The model did not produce El Ninos, the oscillations of tropical temperature that have global effects and are the single largest source of year-to-year climate variability. On the other hand, imperfect models can be a valuable tool in the hands of a competent scientist. By continually comparing the models with the real world, it is possible to be aware of both the limitations and capabilities of the models. Meanwhile, at higher levels, Dr. Cooper wanted a big weather and climate program at Goddard. Weather was NOAA’s bailiwick, but Goddard provided satellite instruments. Climate was the apple of Cooper’s eye. Goddard could take the lead in a new national climate research initiative.

A NASA Climate Plan was needed to gain resources from Congress. The task of producing a plan was handed to Dr. Les Meredith, the Director of Earth Sciences at Goddard. Les Meredith was tall and lanky. He liked to project the “aw, shucks” persona of an Iowa farmer. Meredith did have an Iowa background, receiving his Ph.D. under Van Allen in 1954, on rocket measurements of the upper atmosphere. His interests were more in engineering than in theory. He liked to feign ignorance of theory, but Van Allen commented to me “Les is no dummy,” which was Van’s way of saying that there was actually an astute scientist under the persona. Meredith formed two groups to produce a climate plan. Andy Ingersoll of Cal Tech agreed to chair the science advisory committee. Meredith himself managed the other group, which was an internal GSFC group composed of engineers and scientists with expertise in satellite data. I was in both groups. The internal GSFC group became a big time sink. I traveled to Greenbelt for meetings every week or two. The main purpose of these meetings was to match up climate science data needs with measurement capabilities, especially measurements from space. At each meeting I seemed to end up with a writing assignment for another specific measurement. There was a positive side to the work. I learned about instruments and measurements, and I had to think about the relation with the science. Our climate modeling helped, because we had to either model or make assumptions about all important climate processes. So I developed a broader perspective than I had when I was doing research on the clouds of Venus. Harry Press, manager of NASA’s Nimbus spacecraft, a testbed for meteorological instruments, was duly impressed. He noted the number of sections that I wrote, and said “it’s amazing – he

84 © 2020 James Edward Hansen. All Rights Reserved. brings a new one every week – and they actually make sense!” When the Plan was complete, I had written about half of it. We called it the “Green Book,” for the color of the printed cover.

Goddard’s power-grab floundered, temporarily. Other NASA Centers, especially the Jet Propulsion Laboratory, objected to Goddard’s attempt to gain ownership of a huge national program. Other science agencies, especially NOAA, also objected. There was a basis for objection, beyond jealousy. The proposed climate program was dominated by instruments in space, some of them very large, very expensive. Andy Ingersoll, who had a background in planetary science, began to have misgivings about the plan. The issue was subtle, but profound. Did science drive the choice and nature of the instruments? Or were instruments based on current and planned engineering capability, with scientists doing the best they could with that instrumentation and resulting measurements? This issue lay dormant for years. A monster was lurking and would rise from the ashes a decade later with a NASA program called the Earth Observing System. For the moment there was no approval for a new program, but Cooper and Meredith presumed that Goddard would eventually be granted a big program in climate observations. Thus they continued their climate buildup. Meredith brought in David Atlas, a radar meteorologist from NCAR, to head the biggest group, the Laboratory for Atmospheres, with almost unlimited hiring authority. The Laboratory for Atmospheres soon had more than 100 civil servants and an even larger number of contractors. Their attention to the buildup at Greenbelt was a temporary relief, as I could focus on research.

Anniek’s second pregnancy had reached consummation while I was running back and forth to GSFC for meetings about the Climate Plan. The pregnancy seemed nominal, but on the estimated due date we were still waiting. Two days later, at 2 AM, her bag of water broke. By 5 AM she still had no contractions. We decided that I could go to the airport to catch the 6 AM Shuttle. When I got to Washington, I would check with Anniek on her status. She had the phone number of Meredith’s secretary and would call if contractions started. That plan illustrates how far Anniek went to accommodate my obsessions. Or, you might say, of how unreasonable I was in my expectations. I arrived back home late in the day. Still no contractions. The next day we went to Saint Lukes Hospital, which was just a few blocks from our apartment. The doctor said that we should have come to the hospital immediately after the bag of water broke. The bad news was that that the baby was breech and its head was large. It seemed that natural birth would be difficult and dangerous. Christine Noelle (Kiki, we would call her) had better be delivered Caesarian. I had attended a class so that I could be in the delivery room and “help.” However, when I tried to follow Anniek into the delivery room, a nurse stopped me. I looked at the doctor, who looked at the nurse and said “it’s o.k., he can watch.” The doctor cut one layer of muscle on Anniek’s tummy, pulled it back, and cut another. I was stoic. Anniek insisted on staying awake, with an epidural injection for pain, so she saw Kiki at

85 © 2020 James Edward Hansen. All Rights Reserved. the same time that I did. After they had sewed Anniek back together, the doctor said “I thought he could watch. He’s a scientist.” Anniek’s recovery was more painful than it had been after Erik’s natural birth. She had to stay in the hospital for five days. It was February. Each day at dinner time, I would bundle Erik, and we would walk past the hospital stopping across the street at an appointed time. Anniek would come to the window and wave. Then we continued down Amsterdam Avenue to the V&T Restaurant, where we had pizza, tossed salad and milk for dinner. I could still spend time in the office, because Erik attended the Greenhouse Nursery, on 116th Street, right next door to our apartment. Also on the weekend Erik played with David, Andy and Reiko’s son, in the Lacis apartment on 111th Street. Time at the office was needed! We had bitten off a lot, with few people to chew it. There were still planetary opportunities and obligations, in addition to the new focus on Earth’s climate. I acquired a graduate student, Makiko Sato, in May 1974. She had come to New York City, to Yeshiva University, expecting to work with Al Cameron, but he moved to Harvard. In response to her inquiry about possible thesis research, I suggested a study of light scattering by Jupiter. Makiko’s research on Jupiter’s atmosphere helped us to write a good proposal for an instrument on NASA’s proposed Jupiter Orbiter and Probe Mission. The success of that proposal was important for GISS, showing that our ability to win a place on Pioneer Venus was not a one-off. Makiko and I wrote a paper,73 drawing from her thesis research, in which we inferred the layering of clouds and aerosols in the atmosphere of Jupiter. By analyzing methane and ammonia absorption bands in sunlight reflected by Jupiter, we also concluded that carbon and nitrogen were more abundant on Jupiter than in the atmosphere of the Sun, a conclusion with implications for theories of planetary formation. As described in End of the Rainbow,74 this study helped our instrument pass the confirmation process required to be included on the final payload of the NASA mission, which was renamed as Galileo Jupiter.75 Considering our proposal success on Pioneer Venus and Galileo we might have expected to be supported by about 10 civil service positions, the way Goddard supported Hasso Niemann’s mass spectrometer experiment. That was not the case. All we had was the Iowa mafia: Andy, Larry and me, and the planetary research was only part of our work. We were operating multiple programs with smoke and mirrors. My group’s focus had become Earth’s climate, but for that I borrowed brainpower from our tiny planetary group. Andy was doing the radiation. Larry was working on the convection. We had Gary Russell, but that was temporary, based on a fiat by Jastrow, with Gary’s salary paid by Halem. Once Halem’s move to Greenbelt was complete, I would need money to cover the salary of Gary, assuming that he chose to stay in New York rather than move to Greenbelt. Gary was on the contractor’s staff, not a civil servant. How could GISS survive after the largest program, the weather modeling group, hightailed it out of town? We needed a bigger, stronger team of scientists to fight for our survival. But there were forces working against us, silent forces. I knew they were there, but it was better not to mention them – that would only increase their power. If I acknowledged them, it would make it more difficult to assemble a powerful team. 86 © 2020 James Edward Hansen. All Rights Reserved.

Andy Lacis, Larry Travis, Gary Russell and Makiko Sato

Chapter 14. Assembling a Team

Dr. Jastrow was not concerned about the bill, when he ordered the GISS contractor to provide five programmers to run the climate model at Livermore. Jastrow made other commitments, such as paying costs of Columbia University researchers who worked on problems relevant to GISS research. Jastrow always had strong NASA management support, so the bills got paid. But now things were changing. The weather modeling group moving to Greenbelt was supported by the GARP (Global Atmospheric Research Program) office at NASA Headquarters. GARP was a multi-million dollar per year source of GISS funding, and GARP was leaving. Dr. Jastrow needed to adjust his habits with the loss of GARP funding. However, Dr. Jastrow had not reduced expenditures enough. There was a large budget overrun. So a meeting was held at GISS to describe the budget problem to NASA management. Jastrow was masterful. He made the science understandable and made it seem important. Our future Earth science work would focus on climate. I discussed climate modeling, speaking from notes, but Dr. Jastrow interjected comments, making clear the significance of the research. Dr. Jastrow described the value of a seasonal forecast, a farmer’s forecast, he called it. Seasonal forecasting was not what I was working on, but Jastrow and I were in the same foxhole. It was no time to expose our divergent opinions. However, his words foreshadowed a future conflict. We went to lunch with NASA managers at the Symposium, a Greek restaurant on 113th Street. Morris Tepper was the key NASA manager, the source of GARP funding. Jastrow was at his convivial best, apologizing for the cost overrun and asking for advice about what he should do. Tepper’s response was immediate and loud: “Get ready to go to jail!” Tepper was enjoying the situation immensely. He was making the masterful, articulate Jastrow squirm.

NASA management came to Jastrow’s rescue in the end. NASA Headquarters covered the current cost overrun, but they made clear that the cash cow had left town. No more free milk. NASA Headquarters recognized that there was an issue of institutional viability. GISS needed some funding to survive. It was decided that we would receive a grant of $500K per year for climate modeling. A proposal for peer review would be required every third year.

87 © 2020 James Edward Hansen. All Rights Reserved. The $500K would come from Robert Schiffer’s climate program at NASA Headquarters. Fortunately, Schiffer did not resent the fact that NASA management imposed a large funding obligation on his program. He would give us a chance to show that we could earn the support. This was a tricky situation. The agreement was to fund a so-called NASA Research and Technology Operating Plan (RTOP) to GISS with me as the RTOP manager. However, much of the $500K was needed to cover commitments that Dr. Jastrow had made and institutional costs. The biggest commitment was funding to Columbia University, mainly the Geology Department, to pay the costs of two research scientists working with Dr. Jastrow and a few graduate students. On the other hand, what a spectacular opportunity we had! We had an experiment about to be launched to Venus. Our proposal for the Galileo Jupiter mission had a good chance of gaining confirmation. We were working on a model to help us understand what humans were doing to the most interesting planet of all, our home planet. This was exciting and important work. Work it was. Dr. Jastrow had grown tired of administration. He willed administrative duties to me, as noted in a memo of 29 December 1977 to R. Smylie, Deputy Director of GSFC requesting my promotion to GS-15, which was in the personnel folder that I received upon retirement from NASA. The memo’s first paragraph76 incorrectly claimed that I was competent in experimental work – in fact I was a klutz and relied entirely on David Coffeen, a world-leading expert in polarimetry, for advice on our Venus and Jupiter instruments. Jastrow’s second paragraph77 revealed that he had turned management of the entire GISS budget – a big nuisance – over to me. The silver lining of the administrative work was that I was in a position to push for civil service hires. I obtained three positions in 1978 that elevated our stature in the climate research world.

Gary Russell, Bill Rossow and David Rind gave us a capability in global climate modeling. Gary was the architect of our model. He understood the entire model. Indeed, it was his model. Bill was a post-doc at NOAA’s Geophysical Fluid Dynamics Laboratory and a recent graduate of Cornell where he was a student of Carl Sagan. He had worked on modeling Venus atmospheric dynamics. I noticed him at the Venus conference at GISS in 1974 – he was outspoken already as a student. I thought he would be a valuable antidote to my reticence. Bill did not disappoint. He was voluble and by nature contrary – he liked to debate whatever your position was. David got his Ph.D. at Columbia University, in upper atmospheric dynamics. David worked with Gary in developing our global climate model. His teaching ability was obvious, as he gesticulated with his long arms, explaining atmospheric dynamics and other processes in the global model. I promptly recommended him to the Columbia Geology Department to teach Introduction to Atmospheric Sciences, previously taught by Dr. Jastrow. David got high ratings as a teacher and attracted students to do research with us. After these three hirings in 1978 there was a long period, more than half a decade, until mid- 1984, before I could hire another scientist on civil service. Nor, in that time, did our computer capacity increase above that which we had in 1967 when the 360/95 was installed at GISS. This severe malnutrition of a scientific laboratory was intentional. GISS was a bit of a maverick, running loose on a campus. Some people preferred that GISS not survive, perhaps it was jealousy. We needed more brainpower to be scientifically productive during a long drought.

88 © 2020 James Edward Hansen. All Rights Reserved.

David Rind, Bill Rossow, Tony Del Genio and Inez Fung

Inez Fung and Tony Del Genio were crucial to development of our climate program and to survival of GISS. Fortunately, they worked with us throughout the ‘drought’ without benefit of government jobs, even though they could have readily secured permanent positions elsewhere. Inez arrived at GISS in February 1977 as an NRC post-doc in Halem’s group. On her first day at work, Milt informed her that he was moving the group to Greenbelt. Her NRC position came with a J-1 visa. She thought that she would be deported back to Hong Kong if she did not move with Halem to Goddard. Almost every weekend she ended up commuting on the cheap slow train between Union Station and New York Penn Station. It would be nice if I could say that our budding group attracted a future star to New York, but in reality the main attraction was Jim Bishop, the love of her life, who worked at Columbia’s Lamont Geophysical Observatory. Eventually, in 1978, I learned about her situation and her scientific interests from Mark Cane of Lamont. I had no money then to hire her, but when I contacted NRC they readily agreed that she could work at GISS, if that was her preference. Inez’s knowledge of ocean dynamics and the global carbon cycle was needed for our climate model development and global climate studies. Her knowledge was also essential for a research proposal that I wanted to submit. Resources were needed to supplement the $500K grant from NASA Headquarters, because that money was largely committed. And the new proposal would let us dive headlong into the most important science topic on the planet, as I will soon explain. Inez developed into a widely respected world-class scientist who helped us maintain interactions with different research groups around the world. Inez was later elected to the National Academy of Sciences, and she was a mentor and role model for female students.78 Her story is also chronicled in the 2020 Annual Review of Earth and Planetary Sciences.79

Tony Del Genio was in planetary studies as a graduate student at UCLA, where he developed expertise in atmospheric dynamics. He worked on Pioneer Venus data as a post-doc at GISS from 1978 to 1980. Thankfully, when his post-doc tenure ended, he was willing to work on our contractor staff until I could hire him on the GISS staff in 1985. Tony became our leader in modeling the most difficult and essential aspect of the climate system: clouds and convection. In 1983 Tony began teaching Introduction to Atmospheric Sciences at Columbia, which allowed David Rind to teach graduate level Atmospheric Dynamics and Climate Dynamics courses. Andy Lacis taught two radiation courses, in theory and applications, so we were able to give sufficient relevant training to Columbia students who wanted to work on NASA projects.

89 © 2020 James Edward Hansen. All Rights Reserved. Tony blossomed into a brilliant teaching professor, winning the best teacher award several times in the large Geological Sciences Department. But Tony taught more than the science per se. He taught young people how to be science researchers. I remember one student who said, in effect, “I’m going to run the climate model for some experiments, which will form my Ph.D. thesis.” Tony responded, in effect, “Oh, no you’re not, you have to first show that you understand some physics and persuade us that you have some original ideas worth pursuing.” Tony helped to make our connection to the university effective for both Columbia and NASA. This was vital to justify the location of GISS.

Andy, Larry, Gary, Bill, David, Inez and Tony provided the brainpower needed for research in a university environment. Each of them also had the ability to be a “principal investigator” and write successful research proposals. But how could we obtain graduate students? The best students in Columbia University science departments were taken by the top professors. We needed to create an additional source of good students for Earth science. Our backgrounds were in physics and planetary studies. Our opinion was that physics is the best background training for climate research. Environmental studies or meteorology are fine for some careers, but if the objective is fundamental research, physics is better for basic training. Graduate study in physics, on the other hand, is not necessarily best, if one’s interest is in Earth and planetary science. Physics departments may require some graduate courses that are more esoteric than needed for Earth and planetary research.80 These were thoughts that went through our minds in the late 1970s. We needed a plan to attract physics students late in their undergraduate studies and to persuade them how exciting research in Earth and planetary studies could be.

Proposals had become my forte, it seemed. So it was natural for me to write a proposal to address our desire to work with students, preferably students with basic training in physics. It was not expensive. I no longer have the 1978 proposal, but I believe that I asked for $25K each from the NASA planetary and climate program managers. Amazingly, they agreed to cooperate, and the first Summer Institute on Planets and Climate was held in 1979. During the winter we sent one-page flyers to every physics department in the country. The program was open to undergraduates in the summer after their junior year. Our idea was to work with them before they decided where they would apply for graduate school. We selected 15 students from about 100 applications. It was a 10-week program. The first two weeks had lectures by research scientists who were also great teachers: Wally Broecker, Peter Stone, Jim Walker and Jerry North. Then the students chose from a list of projects proposed by GISS scientists and the four lecturers. The students would work on the problems the rest of the summer, getting advice from GISS scientists, and present results at the end of the summer. The program worked great. We succeeded in getting a few of the students to apply to Columbia and a few others went into Earth science, but not at Columbia. The program was also good for research and interactions at GISS, as most of us would attend the lectures and advise students.

90 © 2020 James Edward Hansen. All Rights Reserved. We needed another proposal. The ozone story had led us to something more important than ozone depletion: powerful greenhouse gases methane and nitrous oxide were adding to the carbon dioxide greenhouse effect. Humans were changing the composition of our atmosphere. These changes would alter Earth’s energy balance and thus Earth’s climate. It made sense for us to continue to pursue planetary research. We could bring a global, planetary, long timescale perspective to the climate research problem. However, I wanted to focus my own time on Earth’s climate. I resigned as principal investigator (PI) for the Pioneer Venus instrument, Larry would take that job, and Andy would be the PI on our Galileo proposal. Our greenhouse proposal would be brash, perhaps ambitious beyond reason, but a sympathetic program manager at NASA Headquarters provided temporary support. However, our research soon drew special scrutiny by the powers-that-be, the sources of funding in the United States government for research on the effect of greenhouse gases on global climate. Ultimately, the proposal was rejected, with harsh consequences for my research group. Let’s not get ahead of the story. Regardless of funding, our research direction had changed. We were determined to focus on the home planet. We could begin with a foundation of knowledge forged by a remarkable group of scientists during the past two centuries. I dug into “greenhouse” history for the sake of accurate introductions in my “expert reports” for lawsuits against governments and the fossil fuel industry. Here I condense that history into one chapter, hopefully in a way that helps illuminate physics needed in later chapters.

91 © 2020 James Edward Hansen. All Rights Reserved. Chapter 15. Greenhouse Giants

The greenhouse effect was described in Chapter 10 in comparing the Goldilocks planets: Venus, Mars and Earth. The greenhouse effect was understood qualitatively two centuries ago, as there are numerous references to it in the literature during the first half of the 19th century. Joseph Fourier, a French mathematician and physicist, wrote81 in 1824: “The temperature [of Earth’s surface] can be augmented by the interposition of the atmosphere, because heat in the state of light finds less resistance in penetrating the air, than in re-passing into the air when converted into non-luminous heat.” Fourier was describing the natural greenhouse effect. Sunlight readily penetrates Earth’s atmosphere, heating the surface. In contrast, heat (infrared radiation) from Earth’s surface is largely absorbed by the atmosphere, with some of this energy radiated back to the surface. Thus the atmosphere acts like a blanket,82 additionally warming Earth’s surface. If Earth had no atmosphere, and still absorbed 70 percent of incident sunlight as it does today, its temperature would need to be -18°C to emit enough infrared radiation to yield energy balance. But the blanket of greenhouse gases forces Earth to warm to a point that the radiation emitted to space equals the absorbed solar energy. That results in the actual surface temperature of +15°C. So the natural greenhouse effect on Earth is 33°C, which is about 60°F. Absent the greenhouse effect, Earth would be uninhabitably cold. Any human-made increase of global temperature, usually called ‘global warming,’ is surely small compared with this natural greenhouse effect. Can the smaller human-made effect really be important? That question has a long history.

Eunice Foote, an American amateur scientist, inventor, and women’s rights campaigner83 is the first person known to have made climate-specific experiments with individual gases. She filled glass cylinders with each gas, including carbon dioxide and moist air, and measured temperature changes of the gases when the tubes were placed in the sun and in the shade. Her 1856 paper,84 Circumstances affecting the Heat of the Sun’s Rays, begins “My investigations have had as their object to determine the different circumstances that affect the thermal action of the rays of light that proceed from the sun.” She showed that a cylinder filled with moist air, and especially one filled with CO2, warmed by tens of degrees Fahrenheit when placed in sunlight.

She concluded “An atmosphere of that gas [CO2] would give to our earth a high temperature; and if, as some suppose, at one period of its history the air had mixed with it a larger proportion than at present, an increased temperature from its own action as well as from increased weight must have necessarily resulted.”

Foote’s conclusion, that CO2 warms Earth, is correct even though absorption of sunlight by CO2 has a negligible effect on Earth’s surface temperature; indeed, it may even cause a slight global cooling of surface air. Absorption of sunlight by CO2 reduces solar heating of the ground and surface air, where the heating has a greater “efficacy” in raising surface air temperature.85 Eunice Foote (1819-1888) deserves recognition for initiating investigation of individual gases, as the first scientist to infer that carbon dioxide and water vapor are important gases affecting Earth’s temperature, and as recognizing the potential importance of CO2 in affecting long-term climate change.86 Unfortunately, no photograph or portrait of Foote seems to have survived. 92 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 15.1 John Tyndall, Svante Arrhenius, and Guy Callendar

John Tyndall, an Irish physicist, is the father of the greenhouse effect, in the sense that he made the greatest contributions to the science. Tyndall converted qualitative statements of Fourier and others into quantitative science through an impressive body of research and laboratory data87, and he communicated his understanding in a language accessible to everyone. Tyndall had keen physical insight, and he made fundamental laboratory measurements with water vapor and carbon dioxide that established the experimental basis for the greenhouse effect. He realized the impact of these gases in keeping Earth’s surface warm, writing (ibid): “This aqueous vapour is a blanket more necessary to the vegetable life of England than clothing is to man. Remove for a single summer-night the aqueous vapor from the air which overspreads this country, and you would assuredly destroy every plant capable of being destroyed by a freezing temperature. The warmth of our fields and gardens would pour itself unrequited into space, and the sun would rise upon an island held fast in the iron grip of frost. The aqueous vapor constitutes a dam, by which the temperature at the earth’s surface is deepened: the dam, however, finally overflows, and we give to space all that we receive from the sun.” Tyndall wrote with elegance about the atmosphere acting as a “blanket.” His other metaphor, that the dam must eventually overflow and “give back to space all that we receive from the sun,” refers to the most fundamental concept, conservation of energy: Earth must eventually radiate to space the same amount of energy that it receives from the Sun. Tyndall, like Foote, had an inkling that changes of greenhouse gases may account for known climate changes during Earth’s history, stating in his 1861 Bakerian lecture88: Such changes in fact may have produced all the mutations of climate which the researches of geologists reveal. However this may be, the facts above cited remain; they (greenhouse gases) constitute true causes (of climate change), the extent alone of the operation remaining doubtful. Tyndall was speculating about the ice ages. As required by the scientific method, he remained skeptical of his own proposition. In correspondence89 of 1 June 1866, he stated that changes in radiative properties alone were unlikely to be the root causes of glacial epochs. Data that

93 © 2020 James Edward Hansen. All Rights Reserved. became available more than 100 years later would reveal that Tyndall was correct in both his original speculation and his cautionary correspondence about root causes, as we will see. Tyndall’s final phrase in the quotation immediately above foreshadows the principal issue in climate science: climate sensitivity. The physics is clear, he says, increased greenhouse gases will cause warming; but the question remains, how much?

Svante Arrhenius, a Swedish physicist and physical chemist, took up Tyndall’s challenge: to quantify how sensitive global temperature is to a specified climate forcing (see Chapter 10). The Sun causes maximum heating at Earth’s surface, because of the atmosphere’s transparency to sunlight. Because of the blanketing of heat radiation by greenhouse gases, convection as well as radiation carries the energy upward to a level at which the energy can be radiated to space. Convection, rising and sinking air, establishes a temperature gradient in Earth’s atmosphere, with temperature falling off with height on average by about 6°C per kilometer of altitude. Absorption by gases, mainly water vapor and carbon dioxide, occurs across the entire spectrum of Earth’s infrared (heat) radiation, but absorption is not uniform across this wavelength spectrum. Therefore radiation to space arises from all altitudes in the atmosphere. On average the altitude from which the energy emerges is about 5.5 km. Not surprisingly, the temperature at this altitude is close to -18°C, the temperature that a solid body requires in order to radiate the energy that Earth absorbs from the Sun. The temperature difference between this altitude and the surface is about 33°C (5.5 km × 6°C/km), which is the present greenhouse effect on Earth. So how did Arrhenius obtain an estimate of the sensitivity of Earth’s temperature to a change of atmospheric CO2? He needed to know the change in infrared absorption as CO2 amount changes. He used infrared measurements by American astronomer Samuel Langley of the full moon. The amount of CO2 traversed by moonlight decreased as the moon rose in the sky.

Arrhenius saw that CO2 absorption did not change linearly with CO2 amount. A geometric increase of CO2 is required to yield a linear increase of absorption. In other words, an equal increase of absorption occurs with each doubling of CO2 amount. He then made elaborate energy balance calculations, which required a year of his time. From these he estimated that doubling atmospheric CO2 would cause a warming between 4.9°C and 6.1°C, depending on latitude and season.90 This first estimate of ‘climate sensitivity’ suffered from errors in Langley’s measurement and other approximations in a complex calculation. Arrhenius later improved upon his first analysis, obtaining a global climate sensitivity91 of 4°C for doubled CO2 and 8°C for quadrupled CO2. This improved estimate of Arrhenius turned out to be within the range found in modern studies, as I discuss further below.

Knut Angstrom, another Swedish scientist, disputed Arrhenius in 1900, arguing that CO2 absorption bands are ‘saturated’, i.e., they absorb nearly all the radiation within narrow spectral 92 regions and negligible energy elsewhere. Therefore additional CO2 would have little effect. Band saturation actually was accounted for in Arrhenius’ empirical evaluation. Saturation is the reason that the warming effect is not linear in CO2 amount. Even at wavelengths where the absorption is saturated at Earth’s surface, absorption is not saturated higher in the atmosphere. Radiation is absorbed and reemitted throughout the atmosphere, with escape to space occurring at the level above which there is little chance of absorption. Added CO2 causes the ‘emission to 94 © 2020 James Edward Hansen. All Rights Reserved. space level’ to be at greater altitude, and because it is colder at higher levels, radiation to space is reduced, causing a planetary energy imbalance and thus a warming that restores energy balance. Arrhenius’ estimate of climate sensitivity in his 1908 book was realistic, and he realized that fossil fuel burning would cause atmospheric CO2 to increase, but he thought it would take several centuries before warming would be significant. This conclusion was partly due to his estimate that 5/6 of the emissions would be taken up quickly by the ocean.

Arrhenius saw the CO2 effects as being beneficial, helping the world feed its growing population: “By the influence of the increasing percentage of carbonic acid in the atmosphere, we may hope to enjoy ages with more equable and better climates, especially as regards the colder regions of the earth, ages when the earth will bring forth more abundant crops than at present, for the benefit of rapidly propagating mankind.”

As long as climate effects of CO2 remained theoretical, they would not be an issue of concern to the public. Broader interest in the topic would require evidence of ongoing global change.

Guy S. Callendar, a British engineer, believed that he found that evidence in 1938. Callendar used records from 147 weather stations around the world to estimate that global temperature increased by about 0.3°C between 1880 and the early 1930s.93 This was a bit larger than the 0.2°C warming that he calculated as the expected warming from increasing atmospheric CO2.

Callendar’s work on both temperature and atmospheric CO2 amount was careful. Because of his engineering training, he paid close attention to difficulties in obtaining accurate measurements. He was able to discriminate among the various attempts to measure atmospheric CO2, and he correctly inferred the approximate magnitude of the CO2 increase over the prior half-century.

Callendar’s claim that atmospheric CO2 was increasing markedly was at odds with understanding of the carbon cycle, which implied that the ocean would quickly take up most of the fossil fuel CO2 emissions. This mystery would not be solved until 1957. Still later, measurements on bubbles of ancient air trapped in Greenland and Antarctic ice cores proved that Callendar’s estimate of CO2 growth since the late 1800s was accurate. Callendar, like Arrhenius, concluded that future warming would be beneficial: “…increases of mean temperature would be important at the northern margin of cultivation, and the growth of favourably situated plants is directly proportional to the carbon dioxide pressure (Brown and Escombe, 1905). In any case the return of the deadly glaciers should be delayed indefinitely.” In the next 40 years after Callendar’s 1938 paper, until the late 1970s, there was no discernable global warming, despite a factor of five increase of annual fossil fuel CO2 emissions. Absence of global warming in a period of such rapidly growing emissions required an explanation if the estimates of climate sensitivity of Arrhenius were in the right ballpark.

An explosion of understanding related to CO2 and climate began with the International Geophysical Year (IGY). The origin of IGY traces to a meeting of several scientists, including Sydney Chapman and Lloyd Berkner in James Van Allen’s living room in March 1950.94 Prior International Polar Years, in 1882-1883 and 1932-1933, showed the value of international cooperation in gathering global data. These scientists suggested that it was time for a worldwide Geophysical Year, in part because of recent advances in rocketry, radar and computing. 95 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 15.2 Roger Revelle, Bert Bolin, David Keeling, Wally Broecker, Syukuro Manabe

Berkner and Chapman obtained approval of the International Council of Scientific Unions for the IGY for the 18 months, July 1957 through December 1958, coinciding with the next period of maximum solar activity. More than 70 nations eventually cooperated in the IGY. In July 1955 President Eisenhower announced that the U.S. would launch small Earth circling satellites as part of the IGY, and a few days later the Soviet Union announced plans to also launch a satellite. , the first artificial Earth satellite, was launched on October 4, 1957, to the surprise of many, especially in the United States. I was a junior in high school then. Within months, after several failed launch attempts, the United States had its own satellites. The was on. NASA was formed on 29 July 1958. Thousands of young people received NASA funding for graduate study, including Andy, Larry and me. Major achievements of the International Geophysical Year included discovery of the Van Allen radiation belts and verification that there was a continuous system of submarine mid-ocean ridges encircling the globe.95 These discoveries were part of a broad collection of data that helped to initiate a comprehensive overview of global geophysical phenomena.

Roger Revelle and Hans Suess altered the course of the CO2 climate story in 1957 with a paper96 in Tellus. The abstract of the paper is misleading, as it states “…it can be concluded that the average lifetime of a CO2 molecule in the atmosphere before it is dissolved into the sea is of the order of 10 years. This means that most of the CO2 released by artificial fuel combustion since the beginning of the industrial revolution must have been absorbed by the ocean.”

The crucial insight from their analysis was that the increase of CO2 in the air from fossil fuel burning has a more difficult time getting into the ocean than prior analyses suggested. Ocean chemistry is a complex soup. Technically, ocean water is a buffered solution that resists a change in acidity. This buffering reduces the net flux of fossil fuel CO2 into the ocean. Bert Bolin and Erik Eriksson soon realized that Revelle and Suess made an approximation for ocean mixing that caused a severe underestimate of the importance of the buffering effect.97 Revelle and Suess treated the entire ocean as a well-mixed volume. It is worth clarifying why that is a bad approximation. Ocean mixing, we will find later, is a crucial physical phenomenon affecting not only ocean chemistry, but also the response time of climate to human perturbations, as well as the strategies and chances of success of human efforts to avoid climate catastrophe. 96 © 2020 James Edward Hansen. All Rights Reserved.

Keeling curve today

The ocean, to a good approximation, can be thought of as consisting of two layers. The upper 100 meters of the ocean is well-mixed, stirred by the wind. The remainder of the ocean, with average depth about 4 kilometers (about 2½ miles) is mixed with the surface layer by the ocean’s overturning circulation on time scales of centuries to millennia. The combination of the chemical buffering effect and the slow exchange between the mixed layer and deeper ocean causes fossil fuel CO2 to have a long lifetime in the air. It requires centuries and millennia for human-made CO2 to be taken up by the ocean. Revelle’s insight was revealed in his summary statement: “Human beings are now carrying out a large-scale geophysical experiment of a kind that could not have happened in the past nor be reproduced in the future.” Revelle saw an opportunity to study geophysical processes, but he also warned of future perils. He speculated that in the 21st century the greenhouse effect might exert “a violent effect on the earth’s climate” (quote in 28 May 1956 Time Magazine). He thought the temperature rise might eventually melt the Greenland and Antarctic ice sheets, which would raise sea levels enough to flood coastlines, and in 1957 he told a congressional committee that the greenhouse effect might someday turn Southern California and Texas into deserts. The International Geophysical Year presented an opportunity to obtain important measurements. Revelle seized that opportunity. Using funds from the United States Committee for the IGY and other sources, he hired a young post-doc from the California Institute of Technology to come to the Scripps Institution of Oceanography to help carry out a world survey of atmospheric CO2.

Charles David Keeling proved to have the dogged determination needed for that job. Keeling’s task was to find instrumentation capable of accuracy an order of magnitude better than prior work. He had to hunt down all potential significant errors in the instrument. He succeeded.

Keeling’s precise data yielded a beautiful curve for atmospheric CO2 amount as a function of time, described today as the ‘Keeling curve.’ Keeling intuited, brilliantly, that data from two carefully selected points on Earth would be very informative. The places Keeling picked were a volcanic mountain in Hawaii and the South Pole. The Hawaii site sampled air arriving from the Pacific Ocean, largely free of local pollution. The South Pole site was even more isolated, yet it was necessary to be aware of emissions from local machinery.

97 © 2020 James Edward Hansen. All Rights Reserved. The annual cycle in the Keeling curve is easy to understand. Atmospheric CO2 at Mauna Loa decreases in the spring and summer as growing vegetation in the Northern Hemisphere sucks CO2 from the air, and CO2 increases in the fall and winter as plant litter decomposes.

As the data record passed the 12-month mark, a long-term CO2 increase became apparent. Later this increase was proven to be largely from fossil fuel burning. At the South Pole the seasonal variation was smaller and the long-term CO2 growth trailed the rise in the Northern Hemisphere. These were understandable consequences of the mixing time of the global atmosphere and the fact that fossil fuel use and vegetation growth were larger in the Northern Hemisphere.

Wally Broecker and Syukuro Manabe led the scientific community to fundamental advances in defining the climate change story in the years following the IGY. The breadth of Broecker’s expertise was unrivalled, as he was the acknowledged authority in ocean geochemistry while also among the world leaders in paleoclimate studies. Broecker’s intellectual depth, curiosity, and outgoing personality were effective in spurring the scientific community to relevant studies.98 Manabe was the authority on the radiative processes that drive climate change, and he developed both simplified models to study climate processes and, together with oceanographer Kirk Bryan, the most comprehensive atmosphere-ocean climate models. In 1965 the President’s Science Advisory Committee (PSAC) delivered a report99 on pollution to President Lyndon Johnson. Johnson signed a statement accepting the report, decrying air, soil and water pollution, and saying that he would give priority to increasing the number of scientists and engineers working on pollution control. It is highly unlikely that he read the report in detail. Perhaps he was even unaware that one of the 11 pollution subpanels was on CO2 and climate.

The CO2 subpanel was blue ribbon. Chaired by Roger Revelle, it included Wally Broecker, Harmon Craig, Dave Keeling and Joe Smagorinsky. Their 23-page report100 concludes: “The climatic changes that may be produced by the increased CO2 content could be deleterious from the point of view of human beings.” Without mention of possible efforts to limit the CO2 increase, their next sentence continues: “The possibilities of deliberately bringing about countervailing climatic changes therefore need to be thoroughly explored.” They suggest deliberate change of Earth’s albedo (reflectivity), noting: “Such a change in albedo could be brought about, for example by spreading very small reflecting particles over large oceanic areas.” Further: “An early development of the needed technology might have other uses, for example in inhibiting the formation of hurricanes in tropical oceanic regions.” How should we interpret this instant leap to what many people today would describe as “mad scientist” implausible geoengineering countermeasures? Was the purpose to draw attention to the seriousness of human-made global warming? Or did this constitute prescient recognition of the unwillingness of governments to constrain fossil fuel emissions? We will return to the subject of deliberate countermeasures to global warming in due course.

Syukuro Manabe and his colleagues, by 1969, had made major advances in modeling and understanding of the global ocean-atmosphere system. Manabe, Smagorinsky, and Strickler101 presented a comprehensive general circulation model of the atmosphere with a realistic hydrologic cycle. Manabe and Richard Wetherald102 used a one-dimensional climate model to

98 © 2020 James Edward Hansen. All Rights Reserved. explore important processes affecting climate change and climate sensitivity. Manabe and Kirk Bryan103 published the first results from a coupled ocean-atmosphere general circulation model. So Manabe had a decade head-start on us. Furthermore, computer capacity of his lab, NOAA’s Geophysical Fluid Dynamics Laboratory (GFDL) located at Princeton University, was much greater than ours at GISS. GFDL was NOAA’s premier climate modeling laboratory, so they could anticipate continual improvement of their computing capability. Computer power, the research community seemed to agree, was the critical need to improve the realism of climate models. Dividing the world up in Texas-sized chunks, as we did, was a questionable approach. Was there a useful role for our modeling approach?

We were in trouble at GISS, and I knew it. We had an old computer and little funding to cover salaries, let alone purchase a new computer. Jastrow’s gambit was the Livermore supercomputer proposition. Dr. Jastrow thought that access to a supercomputer might let us compete with the big modeling centers, GFDL and NCAR. So I dutifully assigned four of the five programmers borrowed from Halem’s group to work on reprogramming the GISS weather model to run on the supercomputer at Livermore. My interest, however, was in a different approach, the coarse resolution global modeling that I had proposed to Rasool. The objective was a model we could run for long time scales, a model that could yield results even on an old computer. That’s the model Gary and the rest of us worked on. Given our tiny group, it was unlikely that we could successfully pursue both Jastrow’s Farmers’ Forecast and our long-term climate topic. It was clear that we were headed for a showdown.

99 © 2020 James Edward Hansen. All Rights Reserved.

Chart used to discuss Farmers’ Forecast and End-of-Century climate problems Chapter 16. Farmers’ Forecast vs. End-of-Century

The Farmers’ Forecast was the focus of Dr. Jastrow’s pitch to Dr. Cooper. I still have the chart he used. It has yellowed with age over the past 40-plus years. By Farmers’ Forecast, he meant long-range forecasting, weeks and months in advance, the timeline segment in which modeling approaches are missing. Dr. Jastrow was superb at making technical material clear to a lay audience or to higher level NASA management. Accurate long-range forecasts would have great economic value for farmers, helping them decide when and what to plant. Jastrow hoped that research on the Farmer’s Forecast provided a reason for NASA to continue to support GISS, as an institute in New York City, with the weather project relocated to Greenbelt. The chart shows climate ‘predictive capability’ as a function of the length of the forecast, both the capability existing ‘today’ (the late 1970s) and the potential predictability in 5-10 years assuming aggressive deployment of relevant global observations and development of global climate models. Such a rapid improvement of forecasting ability was unrealistic, and NASA managers would likely recognize that, but they would not object to ambitious goals. The accuracy of local weather forecasts was not good in the 1970s. Predictions were usually accurate for a day or so, at best, and not reliable for longer lead times. It was realized that the chaotic aspect of atmospheric motions, as described by Ed Lorenz104, would always prevent reliable local forecasts at time scales beyond a week or two. Jastrow drew an optimistic curve for increasing weather predictability in 5-10 years, assuming accurate global satellite observations and improved high-resolution weather models.

Dr. Jastrow discussed the weather end of this diagram first, the short time scales, to help explain the diagram. The time scale is increasingly compressed toward longer time scales, and the nature of predictability changes as the time scale increases. For time scales of a few weeks to a few months, the Farmers’ Forecast period, prediction of weather on a specific day is not possible or needed. Instead the goal is knowledge of what week is best to plant or harvest and of whether a season is going to be wetter than normal or drier than normal. Dr. Jastrow argued that high predictability of average weather was possible on the Farmers’ Forecast time scale, because atmospheric boundary conditions such as sea surface temperature patterns, soil moisture and snow cover, would affect the average weather on those time scales. Anomalies in these boundary conditions could be observed at the time of forecast, and the model would compute or specify how these anomalies changed in the future. 100 © 2020 James Edward Hansen. All Rights Reserved. Finally, Dr. Jastrow argued that there was also significant predictability at the ‘end-of-century’ time scale. On such long time scales the interest is not in specific year-to-year changes, such as those caused by El Ninos, which are unpredictable so far ahead. Instead, the interest is in long- term global and regional climate change caused by factors such as changes of atmospheric composition, land use, solar irradiance and the level of volcanic activity.ӧ

Dr. Jastrow’s chart showed great optimism about potential predictability, especially on the time scale of the Farmer’s Forecast. Improved predictability was the carrot that Dr. Jastrow was proffering. He argued that the economic benefits are greatest for a good seasonal forecast. The carrot was important. We needed more funding, if GISS was to be viable. The $500K per year that NASA Headquarters agreed to provide GISS after departure of the weather program to Greenbelt hardly covered institutional costs and commitments that Dr. Jastrow had made, commitments that he said were needed to “keep the doors open.” NASA Headquarters had left open the possibility that we could propose additional research for additional funding. Dr. Jastrow was suggesting that the potential for a Farmer’s Forecast was so great that Headquarters should supply greater funding for research on it. Dr. Jastrow’s chart had “??” for the numerical modeling approach that should be used for the Farmers’ Forecast.

My interest was in what Dr. Jastrow called End-of-Century predictions. My proposal to the stratospheric research program at NASA Headquarters had been approved. The funding helped support development of the coarse resolution climate model. Specifically, it allowed me to pay the salary of Gary Russell, who did not want to move to Maryland. We were still early in our work on the three-dimensional (3-D) coarse resolution model, so I did not have results for end-of-century climate simulations. All that I could show were calculations that we had done with a simple 1-D (vertical column) climate model, while we were working on the 3-D climate model. These calculations were for the natural climate experiment that was playing out over our heads in 1963 when Andy and I were taking the Ph.D. qualifying examination. Now we could use the measurements that we had made on a cold winter night in Iowa in 1963 as the moon was obscured by the sulfate aerosols produced by the massive eruption of Mount Agung on the island of Bali, Indonesia. The idea was to use this volcanic eruption as a natural climate experiment. The stratospheric aerosols produced by the Agung eruption reflected sunlight to space, reducing solar heating of Earth so much that it should have a discernable cooling effect on Earth.

Benjamin Franklin had the idea a bit earlier than us. Franklin wondered whether excessively cold weather in the early 1780s might be a result of an incessant “dry fog” that was prevalent then, especially in Europe. The dry fog was believed to be a result of continuing volcanic eruptions near Iceland, which poured out lava and sulfurous gases. The Sun’s rays were so enfeebled by this dry fog that, when collected in the focus of a “burning glass,” according to Franklin, they could “scarce kindle brown paper.” Franklin’s idea, that volcanic aerosols reduced solar heating, was plausible, but he lacked the scientific tools and data needed to investigate the idea. We had fairly good global data for the

101 © 2020 James Edward Hansen. All Rights Reserved. stratospheric aerosols produced by the Agung eruption, which was the largest eruption in the past 50 years. So Agung provided a useful test of the climate models we were developing. Earth is heated by the Sun at an average rate of about 240 W/m2, averaged over the entire planet, thus averaged over day and night.105 Based on our 1963 lunar eclipse data and other data, we could estimate that the Agung aerosols reflected about 1 percent of the sunlight striking Earth at the time of maximum stratospheric aerosol amount. Thus the maximum (negative, cooling) forcing by the aerosols was about ̵ 2.4 W/m2. The forcing slowly diminished over the next year as the aerosols descended into the lower atmosphere and were washed out. When we put the aerosol data into our 1-D energy-balance model, the calculated temperature changes following the eruption were in good agreement with observed temperature changes in Earth’s stratosphere and at the surface. We submitted a paper to Science in the summer of 1977, and it was published in early 1978.106

Robert Frosch, the NASA Administrator, read our paper. Frosch was unusual for a NASA Administrator, a top-flight scientist as well as engineer, with a Ph. D. in theoretical physics. Frosch contacted Ichtiaque Rasool, chief scientist in NASA Earth Sciences, and recommended that NASA be prepared to make appropriate observations at the next large volcanic eruption. Frosch’s interest was useful for Jim Pollack and his colleagues at NASA Ames Research Center, helping them get support for aircraft instrumentation. They were ready to obtain measurements of volcanic aerosols after the eruptions of El Chichon in 1982 and Pinatubo in 1991. Frosch’s interest in the Mount Agung paper did not result in new funding to GISS. However, Jastrow, Cooper and climate program managers at Headquarters were all aware of Frosch’s comment. This helped to buy us some time to work on our climate model.

We needed a 3-D Global Climate Model (GCM). A GCM is an essential tool for climate studies because it lets climate processes interact. GCMs are based on basic physical principles: conservation of energy, mass and momentum, plus the ideal gas law defining the relation between atmospheric temperature, pressure and number density of gas molecules in the air. GCMs are complex because of source and sink terms in these conservation equations, and because of the complicated nature of water. There is a separate equation for conservation of water, but keeping track of water is challenging because of phase transitions that occur between water vapor, liquid water and ice. The climate model needs sub-models for clouds, precipitation, soil moisture, rivers, lakes, and so on. We did not yet include a dynamical ocean model that could move heat from one location to another, but we did include the heat capacity of the upper layer of the ocean that is mixed rapidly by waves. The thermal inertia of this ocean layer is needed so that the computed surface temperature has a realistic seasonal cycle.

Coarse resolution was our savior, but the community’s bugaboo. When Kiyoshi’s initial simulations revealed that 8×10 degree resolution yielded a realistic atmospheric circulation, I was euphoric. It meant that we could do useful climate simulations on our old (1967) computer.

102 © 2020 James Edward Hansen. All Rights Reserved. Moore’s Law is the remarkable empirical fact, noted by Intel co-founder Gordon Moore in 1965, that the number of transistors that can be packed into a given space approximately doubles every two years. Computer speeds increased at a similar rate, at least for a few decades. Of course, to take advantage of Moore’s Law you must buy a new computer regularly. By 1977 our 1967 computer was five doublings behind state-of-the-art, a factor of 32. The 8×10 model, with Texas-size grid-boxes (500 miles across), was almost eight times faster than the 4×5 model. Ten boxes covered the contiguous 48 states in the U.S., but Texas, Florida and Maine stuck out into three additional boxes. A gridbox surface could be part land and part ocean, with atmosphere-surface interactions computed separately for land and ocean fractions. David Rind looked at the simulations in detail. He found that the 8×10 model had recognizable high and low pressure systems, but they did not move as fast as real storms. A real-world storm might start in the Gulf of Mexico, move up the East Coast, and end up near Norway. In our model the storms tended to poop out when they reached New England, but another storm would form to carry heat poleward. Because the poleward transport of heat is driven by the temperature gradient, the model found a way, albeit imperfectly, to move the heat. This is an example of the benefit of the careful treatment of the fundamental equations by Akio Arakawa and Gary Russell. Of course, we needed to be aware of the model’s limitations due to its coarse resolution, but we had a tool that was useful for many purposes.

Such coarse resolution is not good for weather forecasting, which requires accurate tracking of the motions of individual high and low pressure systems. Nor was it likely that such resolution would be useful for the Farmers’ Forecast. We did a set of forecast experiments with our coarse-resolution model. We made seasonal simulations with and without inclusion of observed sea surface temperature (SST) anomalies at the beginning of the season. The model runs that included the SST anomalies produced slightly more accurate temperature anomalies during the following three months than the set of model runs that did not include the initial SST anomalies. I showed this result during a visit by Dr. Cooper. Dr. Jastrow described it glowingly as a first step toward his Farmers’ Forecast, implying that we would keep improving the model and input data as needed for a better forecast. That was a problem. Forecasting experiments based on SST anomalies were trivial, requiring only addition of observed SST anomalies to the climate model’s SST climatology – the SST distribution computed by the model. If we wanted to do better, we would need to model the slowly changing boundary conditions such as soil moisture and vegetation health. There was no way that I was going down that path. There were bigger groups, with much greater resources, already working on those things. Dr. Jastrow would not find out that I was making no effort in that direction until the next visit by Dr. Cooper or other NASA brass. So we had a little time to make progress in things that we wanted to do.

Meanwhile, a great opportunity arose. Bob Schiffer, head of the climate program at NASA Headquarters, was interested in finding a role for NASA in the CO2 climate problem. We had a suggestion: add a dynamic ocean model to the budding GISS climate model, and keep track of the carbon in the ocean, including the transfer of fossil fuel CO2 into the ocean. 103 © 2020 James Edward Hansen. All Rights Reserved. There was an ongoing scientific puzzle: a ‘missing carbon sink.’ The amount of fossil fuel CO2 injected into the atmosphere was known accurately. The increase of CO2 in the air was measured accurately by Dave Keeling, and found to be only 60 percent of the fossil fuel source. Much of the other 40 percent was surely going into the ocean, but Wally Broecker argued persuasively that the ocean was not taking up that much CO2.

Other scientists looking at data on deforestation, which was another CO2 source, and regrowth of vegetation, which is a CO2 sink, could not account for the 40 percent of fossil fuel CO2 that was not appearing in the air. We wanted to look at the problem with a global transport model, including carbon isotopes, and try to help resolve the mystery of the missing sink. We included Wally Broecker as a co-investigator because he was the world’s leading expert on ocean geochemistry and we wanted his advice. However, the proposal would also be a way to get money to pay for Wally’s students without hamstringing GISS research programs.

Another part of our proposal was to investigate climate sensitivity. We had initiated a doubled CO2 experiment with our 3D GCM. The experiment was not complete – even with near-Texas-size grid-boxes the model was slow on our computer – but it looked interesting. Our model seemed to yield almost twice as much global warming as Manabe had found in his most recent climate model experiments.

We proposed to complete this 2×CO2 experiment. We would analyze model diagnostics to investigate what physical processes were causing our model to yield greater warming than Manabe had found. We would also compare our model with real world data to help assess the reliability of the model.

We wrote still another proposal, for cloud studies. Clouds were the most uncertain climate feedback. If the world became warmer, would cloud cover increase or decrease? Would clouds move to higher altitudes? Cloud changes might be the biggest factor affecting how sensitive climate is to forcings such as increased CO2. We proposed to use satellite observations to assess the realism of cloud modeling in climate models.

I submitted both the CO2 and cloud proposals to NASA Headquarters on 1 July 1979. Jule Charney somehow got a copy of the CO2 proposal, probably from our co-investigator Peter Stone, a colleague of Charney at MIT.

Charney’s interest in our CO2 proposal would turn out to make all the difference to the future of our climate program, and to the future of the Goddard Institute for Space Studies.

104 © 2020 James Edward Hansen. All Rights Reserved.

Jule Charney Chapter 17. Charney’s Puzzle: Is Earth Sensitive?

President was concerned about growing United States dependence on oil from the Middle East. On 18 April 1977, just three months after assuming the Presidency, he delivered an Address to the Nation on Energy, while sitting in the White House, wearing a sweater, with the White House thermostat turned down. Oil and gas supplies are limited, President Carter said, so “we need to shift to plentiful coal” and “we must start now to develop the new, unconventional sources of energy that we will rely on in the next century.” Conventional fossil fuels are the oil, gas and coal that can be readily extracted from large deposits in the ground without special efforts and expenditure of energy. Unconventional energies include tar sands and “tight” gas and oil deposits that are extracted by high pressure hydraulic fracturing (fracking) of rock formations. Coal gasification is another example of unconventional fuel. Because energy is required to extract these fuels, they are more carbon- intensive than the conventional fossil fuels, that is, they emit more CO2 per unit of useful energy for the consumer. Unconventional fossil fuels also produce regional pollution, including expanding plumes of polluted groundwater. “We’ve always been proud of our leadership in the world. Now we have a chance again to give the world a positive example,” President Carter concluded. Indeed. United States actions mattered. Between 1915 and 1950 the United States emitted 45 percent of global fossil fuel emissions, with 200 other nations emitting 55 percent. By 1977 emissions from other nations had climbed, but during Carter’s presidency U.S. annual emissions were still more than one-quarter of global annual emissions. President Carter obviously needed good scientific advice. President Carter’s Science Adviser, Frank Press, requested advice from the President of the National Academy of Sciences, . The charge that the Science Adviser gave to the National Academy was broad, ending: “To summarize in concise and objective terms our best present understanding of the carbon dioxide/climate issue for the benefit of policymakers.”

105 © 2020 James Edward Hansen. All Rights Reserved. That charge was a license to provide broad advice related to the crucial issue of energy policy. It should have been crystal clear that President Carter was in desperate need of advice on Earth’s climate system. Fourteen years had passed since the 1965 PSAC CO2 study headed by Roger Revelle. Understanding of the climate issue had advanced considerably. Philip Handler chose a stellar group of meteorologists and oceanographers for the National Academy study of the issue: Akio Arakawa, D. James Baker, Bert Bolin, Jule Charney, Robert Dickinson, Richard Goody, Cecil Leith, Henry Stommel and Carl Wunsch. Jule Charney was the obvious choice to chair the study. It is likely that Handler made that decision and consulted with Charney before deciding on committee membership.

Charney chose a narrow focus, on climate sensitivity, for the National Academy study. This was consistent with the limited time for the study. The study group met for five days, 23-27 July 1979. Charney had continuing consultations with study group members and other scientists in the following weeks before completing a 33-page report.107 Charney’s narrow focus was ingenious, yielding clear definition of the core scientific issue in global climate change. His sharp focus provided a quantitative framework for thinking about climate sensitivity. The value of Charney’s framework has not diminished over time.

CO2 in the air was observed to be increasing rapidly. Keeling’s data showed that CO2 had passed 335 ppm (parts per million), was increasing more than 1 ppm per year, and the rate of growth was increasing as annual fossil fuel use continued to increase. It was known that a lot of fossil fuels were present in the ground, so, if fossil fuel use continued to increase, airborne CO2 at some point would be twice as great as the preindustrial level, estimated to be about 280 ppm.

Charney defined an idealized gedanken problem: how much would global temperature increase if the amount of CO2 in the air doubled from its preindustrial amount? Such a doubling would likely occur in the 21st century, if there were no efforts to constrain fossil fuel use. The problem was idealized in several ways for the sake of being a tractable, well-defined problem. The global warming was defined as that which exists after the planet returns to near- equilibrium with space, in response to the planetary energy imbalance created by the added CO2. The report suggested that delay in attaining full warming could be as much as “a few decades.” We now know that the study group greatly underestimated the delay caused by the ocean’s thermal inertia. They also did not seem to recognize that the delay time is a very strong function of climate sensitivity, a matter that was not clarified until the mid-1980s. The lag in climate response has important practical implications. It causes human-made climate change to be an intergenerational matter. One generation can cause climate change that becomes large only during later generations. Because of the importance of this climate change lag, we defer discussion of it to a later chapter, where we can be quantitative.

Climate feedbacks were a principal topic of the Charney report. Charney did not explicitly divide feedbacks into the categories of fast feedbacks and slow feedbacks, but the nature of the Charney study and report implicitly led to such a framework for analysis.

106 © 2020 James Edward Hansen. All Rights Reserved. Consider first the ‘no feedback’ case. If the amount of CO2 in the air is doubled and everything else is held fixed, how much will Earth’s surface temperature increase? Everyone gets the same answer, if they do the radiation calculation accurately. Earth’s surface and lower atmosphere must warm about 1.2°C (2.2°F) to restore energy balance with space.

As a reminder: increased CO2 makes the atmosphere more opaque in the infrared part of the spectrum. Thus radiation to space occurs from greater altitudes, where it is colder. The amount of radiation to space is therefore reduced, and the planet is out of energy balance: less energy is emitted to space then is received from the Sun. So Earth warms until energy balance is restored.

Thus the no-feedback climate sensitivity is about 1.2°C for 2×CO2. Doubled CO2 is a forcing of about 4 W/m2, so the no-feedback sensitivity can also be stated as 0.3°C per W/m2. The conclusion would be that climate is not very sensitive, if there were no feedbacks. However, if the world warms up 1.2°C, that will cause other things to change. Those changes, called climate feedbacks, can either amplify or diminish the no-feedback climate sensitivity.

Jule Charney was delighted that our model gave a different global warming than Manabe’s. Charney had a predilection for 3-D GCMs, perhaps in part because he was instrumental in development of the fundamental equations at the core of the models, but mainly because these global models provide a framework within which the various climate feedbacks can interact. Different results from two different models provided Charney something to chew on. Charney invited me to give a presentation on our results during their workshop at the Woods Hole Oceanographic Institute in Massachusetts. I was glad to have an excuse not to go. Their workshop occurred during the first Summer Institute on Climate and Planets, which I was running. I was reluctant to reveal my ignorance before Charney’s stellar committee, which included, for example, Robert Dickinson, recognized as a genius, who knew everything that I knew about climate feedbacks, and much more. Instead, we scheduled a telecon on which I tried to answer Charney’s questions. In addition, after their workshop ended, Charney sent Arakawa to stay with us a few days, examining computer output to try to understand our model and its simulated climate response.

Manabe’s latest model yielded a climate sensitivity of 2°C for 2×CO2, while our model gave almost 4°C. Charney called a few times after the workshop, while he was finishing the report, and we discussed some of the possible reasons for the difference. Clouds were likely one reason. Manabe specified the cloud distribution in his model to make it as realistic as practical, and he kept the clouds the same in the 2×CO2 experiment. So the clouds were warmer in the 2×CO2 world, and the cloudtops radiated more energy to space. Clouds were computed in our model, occurring in atmospheric layers and at times when the air became saturated. Some cloud types tend to occur at a given temperature, so in the 2×CO2 world as the atmosphere warmed these clouds moved to higher altitude. It is colder at the greater altitude, so the clouds radiate less energy to space than they would if they had stayed at the same altitude (in Manabe’s model, with fixed cloud heights, these clouds are hotter and radiate more

107 © 2020 James Edward Hansen. All Rights Reserved. energy to space). Also the cloud cover decreased slightly in our 2×CO2 world, which increased the amount of sunlight absorbed by Earth. Sea ice was another difference between our models. Manabe’s control run (climate simulation with 1×CO2) had less sea ice around Antarctica than the real world, while our control run had more sea ice than observed. The area with sea ice decreases in the 2×CO2 world, which is an amplifying feedback, because the ocean is much darker than sea ice, so it absorbs more sunlight. Because Manabe’s model did not have as much sea ice as ours to begin with, the amplification of warming due to sea ice loss was less in Manabe’s model than in our model. Water vapor was the largest feedback in both models. The amount of water vapor that the air can hold is a strong function of temperature, as readily noticed in daily life. If we let outdoor air into the house in winter and heat it to room temperature, the relative humidity becomes very low – even if it is snowing outside, which implies that the humidity was near 100 percent outside. Our models were similar in this calculation, but multiple amplifying feedbacks reinforce each other. Therefore, because the cloud and sea ice feedbacks were larger in our model, the water vapor increase in our model was larger than in Manabe’s model.

Charney decided that his central estimate for climate sensitivity was 3°C for 2×CO2, which was about the midpoint between the two GCM results. Discussion of feedbacks in the Charney report, aided by 1-D models, would have implied 2.4°C as the most likely sensitivity. However, Charney told me that he trusted the 3-D models more, because they allowed interactions among the feedbacks and included expected amplification of warming at high latitudes. Choosing an uncertainty range was more difficult. Charney settled on 3 ± 1.5°C for expected equilibrium global warming due to doubled CO2. That is a large range, a factor of three, from 1.5°C to 4.5°C. Furthermore, he later clarified that the estimate only meant that there was at least a 50 percent chance108 that real world sensitivity was within the 1.5-4.5°C range! Forty years later, the range would not be much narrower, if it relied entirely on climate models. One problem with models is that we are never certain that all significant processes are included. Also some processes, such as cloud formation, are difficult to simulate, and a small change of cloud cover can have a significant effect on the amount of solar energy absorbed by Earth. Fortunately, Earth’s climate history provides ways of assessing climate sensitivity that are potentially much more accurate, as we will discuss in due course. For now, I make only a few points of clarification. We must discuss the time scale of different climate processes, including the ocean and so-called “slow” climate feedbacks.

Charney’s climate sensitivity is the ‘fast-feedback’ climate sensitivity. It includes the feedback effects of water vapor, clouds and sea ice. Today we understand that the water vapor feedback is strongly amplifying, the sea ice feedback is amplifying, and the cloud feedback is uncertain but believed to be near neutral or slightly amplifying. On net these fast feedbacks increase climate sensitivity from 1.2°C to about 3°C for doubled CO2. Charney’s idealized gedanken problem assumes that the Greenland and Antarctic ice sheet sizes are fixed, consistent with an expectation that ice sheets change only on millennial time scales. However, given enough time, warming will cause ice sheets to shrink, exposing a darker surface

108 © 2020 James Edward Hansen. All Rights Reserved. that absorbs more sunlight, which causes more warming. Other slow feedbacks are also excluded in Charney’s evaluation of climate sensitivity, for example, the melting of tundra with release of greenhouse gases CO2, CH4 and N2O. Forests would expand to higher latitudes in the Northern Hemisphere in a world with 3°C warming, covering a much large area. That feedback was not included in either Manabe’s model or our model. “Earth system sensitivity” is the terminology used for climate sensitivity when all feedbacks are included. As we will see, Earth’s history reveals that the slow feedbacks, on net, are also amplifying, so Earth’s climate is even more sensitive than indicated by Charney’s analysis.

Conclusions of Charney’s report ended with: “To summarize, we have tried but have been unable to find any overlooked or underestimated physical effects that could reduce the currently estimated global warmings due to a doubling of atmospheric CO2 to negligible proportions or reverse them altogether. However, we believe it quite possible that the capacity of the intermediate waters of the oceans to absorb heat could delay the estimated warming by several decades. It appears that the warming will eventually occur, and the associated regional climatic changes so important to the assessment of socioeconomic consequences may well be significant, but unfortunately the latter cannot yet be adequately projected.” The Preface to the Charney report, written by Verner E. Suomi, Chairman of the National Academy of Sciences Climate Research Board, states “The conclusions of this brief but intense investigation may be comforting to scientists but disturbing to policymakers. If carbon dioxide continues to increase, the study group finds no reason to doubt that climate changes will result and no reason to believe that these changes will be negligible. The conclusions of prior studies have been generally reaffirmed. However, the study group points out that the ocean, the great and ponderous flywheel of the global climate system, may be expected to slow the course of observable climatic change. A wait-and-see policy may mean waiting until it is too late.” Suomi correctly notes that the caveat about the delay caused by the ocean is not a benefit. It means that a “wait-and-see” approach by policymakers could be dangerous! The ultimate charge to NAS was: “To summarize in concise and objective terms our best present understanding of the carbon dioxide/climate issue for the benefit of policymakers.” Does the report adequately inform policymakers? Suomi’s words “…comforting to scientists but disturbing to policymakers…” are relevant. But did the report disturb policymakers? Were we, the scientific community, clear enough, strong enough, in our warnings to policymakers?

For my group, the chance to interact with Charney was a privilege and good fortune. Charney treated us with the respect accorded more established researchers, despite the coarse resolution and unpublished status of our climate model. Charney’s approval was noticed by NASA Headquarters. Publicity surrounding the Charney report included the fact that our model results were a prominent part of the report. It is likely that Charney’s approbation played a role in the decision of NASA to fund both the CO2 and cloud research proposals! We received $100K funding immediately for the CO2 research and approval for $230K per year beginning the next fiscal year. The cloud research also was funded, beginning, if I remember right, at a level of $100K per year.

109 © 2020 James Edward Hansen. All Rights Reserved. I had stopped work altogether on the Farmers’ Forecast. I had ammunition for any dispute with Dr. Jastrow. Our model with coarse resolution did a good job of simulating the atmosphere’s general circulation, consistent with our initial proposal, which was guided by advice of atmospheric dynamist Prof. Peter Stone. I wanted to focus on the physics of long-term climate. Farmers’ forecasting, essentially extended range weather forecasting, required a different focus. Before any fight could occur, a referee stepped into the ring. The NASA Inspector General. He would alter our courses, both Jastrow’s and mine. The following two years were probably the best years of my research career. We had money for students and research associates, and I worked assiduously on a paper on CO2 and climate. I thought we could say more than the Charney report had said about expected global warming.

110 © 2020 James Edward Hansen. All Rights Reserved.

Fig. 18.1. Anniek, Erik and Kiki in Copenhagen in 1981.

Chapter 18. Original Sin and the Inspector General

My original sin seems to have been committed in August 1981 in the Moon Palace with Dr. Jastrow and Walter Sullivan, the science writer for the New York Times. I was in a rush, getting ready for a flight to Amsterdam. Anniek and the kids had already been in Holland for 10 days, where I was supposed to meet them. We planned to borrow Anniek’s sister’s car and drive to Hamburg for an IAMAP (International Association of Meteorology and Atmospheric Physics) meeting. We would then drive to Copenhagen, the first time in Denmark for any of us. We could stay at a hotel right next to Tivoli Park and we could go see the mermaid in the harbor. It seemed to be such a good plan…but wait, I am getting ahead of myself.

One problem that I proposed for students during the 1979 Summer Institute on Planets and Climate was to estimate global temperature change in the past century. Weather stations around the world had been making observations that long. Wouldn’t it be interesting to compare observed temperature change in the real world with what is expected due to increasing CO2, using the climate sensitivity that the Charney study suggested? Prior temperature analyses109 emphasized the Northern Hemisphere, where most weather stations were located. However, if we think about Earth as a planet that we are exploring, we would be happy with the number of measurements in the Southern Hemisphere. The data could not yield the absolute global average temperature, because temperature varies a lot in short distances, but global warming should have a smoother distribution – if it were occurring. Roy Jenne of the National Center for Atmospheric Research sent us a computer tape with data to 1978 taken at thousands of stations around the world. Dealing with those data was a bigger job than I guessed. There were short records, long records, broken records for different stations. The computer programming was too much for a student to complete during the Summer Institute. But now I had funding, so I hired a professional programmer, Sergej Lebedeff, to help. The basic idea, in my proposed data analysis scheme, was that point measurements contain information for a large area. If a winter is unusually cold in New York, it is probably a cold winter in Philadelphia. Weather models and observations show that temperature anomalies have 111 © 2020 James Edward Hansen. All Rights Reserved. spatial scales of a few thousand kilometers. So we had a useful estimate of the temperature anomaly at a point if we had at least one station located within 1000 kilometers (600 miles). The merit of this scheme was that it allowed us to extend temperature change estimates well into regions where few people lived, such as the Arctic and throughout Siberia. This idea worked quite well, as we would prove later.

What we found was that the world had become warmer over the period 1880-1978 by 0.4°C, which is about 0.7°F. This was a bit of a surprise, because analyses for the Northern Hemisphere had shown a strong cooling, about 0.5°C, between 1940 and 1970. There was a lot of variability in space and time, but we showed that, over the full period, there was global warming.

Was this warming caused by increasing CO2? It would not be possible to prove that, but we could at least calculate the expected warming due to increasing CO2 and compare this with observations to see if there was consistency. We made calculations with a simple (1-D) climate model, so that we could examine many cases. We chose feedbacks that seemed reasonable to us, for example, water vapor was assumed to increase when the atmosphere became warmer. The climate model had a sensitivity of 2.8°C for 2×CO2, which was near the middle of the range estimated by Charney. We included the thermal inertia of a 100-meter thick ocean mixed layer, and we allowed heat to be exchanged with the deeper ocean as a diffusive process, with the diffusion coefficient based on the rate at which inert chemical tracers were observed to penetrate the real ocean. We knew there were other significant climate forcings, some of which were measured. We assumed that the cooling effect of human-made aerosols tended to offset greenhouse warming by non-CO2 gases, but that would not be true on a hemisphere-by-hemisphere basis or as a function of time. Indeed, aerosols were a good candidate for causing the 1940-1970 Northern Hemisphere cooling, but aerosol changes were unmeasured.

The calculated global warming over the 100-year period was consistent with observations. The large temporal variability in the observations prevented a stronger statement, but we could make testable predictions, which we noted in the paper’s abstract: Summary. The global temperature rose by 0.2°C between the middle 1960s and 1980, yielding a warming of 0.4°C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980s. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage. The paper employed climate modeling, modern observations of ongoing climate change, and Earth’s paleoclimate history. None of these alone, or even two in combination, would permit such extensive conclusions. The combination of all three permits greater insight. 112 © 2020 James Edward Hansen. All Rights Reserved. I wanted the implications of the science for energy policy to be explicit and unambiguous, and thus wrote a concluding paragraph: Political and economic forces affecting energy use and fuel choice make it unlikely that the CO2 issue will have a major impact on energy policies until convincing observations of the global warming are in hand. In light of historical evidence that it takes several decades to complete a major change in fuel use, this makes large climate change almost inevitable. However, the degree of warming will depend strongly on the energy growth rate and choice of fuels for the next century. Thus, CO2 effects on climate may make full exploitation of coal resources undesirable. An appropriate strategy may be to encourage energy conservation and develop alternative energy sources, while using fossil fuels as necessary during the next few decades.

Publication of this paper required almost a year – I submitted it to Science three times and to Nature once. Science returned the first submission, saying that it was three times longer than they could publish. However, I knew that they sometimes published papers exceeding their nominal limit. I wanted the paper to include the entire story – from the energy balance of the planet to policy implications -- so I kept reducing the length 10-15 percent and resubmitting it. I was confident that Science was interested in the paper, because the editor, Phil Abelson, commented on it to Jule Charney.110 Abelson’s comment was a criticism, about exponential growth in energy growth scenarios, but it showed he had looked at the paper in detail, so I was encouraged. I revised some scenarios for future energy use and resubmitted the paper. Eventually Science accepted it! It was still 10 full journal pages, which was an unusually long article for that journal. It would finally appear in press111 in late August 1981.

Meanwhile, during the long effort to publish the Science paper, GISS entered a quieter period of research. We survived departure of the large GARP-funded group in part by returning one floor of the GISS building to Columbia University, thus reducing our rent payment. We did not see much of Dr. Jastrow, who was busy writing books and teaching. Also, he worked with several scientists who were investigating use of satellite observations to explore earth resources. Jastrow’s textbook Astronomy: Fundamentals and Frontiers, co-written with high school teacher Malcolm Thompson and published initially in the early 1970s, was excellent but required revisions for successive editions. Annual enrollment in Jastrow’s course for Columbia and Barnard students, Stars, Planets and Life, grew to more than 400. Popularly known as “Astro Jastrow,” it was undemanding and thus a student favorite to fulfill their science requirement. I was glad that Jastrow also began teaching at Dartmouth and bought a house there. All that time at Dartmouth delayed the anticipated confrontation over the Farmer’s Forecast. That delay provided the time needed for an unexpected intervention.

Dr. Thaddeus, as the senior GISS scientist, suggested that he and I seek a meeting with the Goddard Director. Pat was concerned about the future of the Institute. Dr. Jastrow had been talking about perhaps partially retiring from the government, working only half-time. I continually rejected Pat’s suggestion that we seek a meeting. I argued for a delay, on the rationale that our case for Goddard support post-Jastrow would get stronger if we kept working

113 © 2020 James Edward Hansen. All Rights Reserved. hard and produced scientific results. Our climate research funding had just begun. I had high hopes that our paper for Science would be accepted and have a good impact. I do not remember for sure which came first: my eventual consent for a trip to Goddard or news of the NASA Inspector General investigation of GISS. Probably it was the latter. I vividly remember the trip. Pat was as bad as me about waiting to the last minute. When we hailed a cab on Broadway at 112th Street, it was less than half an hour until our flight departure from LaGuardia. There would be a later flight, but then we would be late to the meeting. Pat urged the driver to go fast and shouted at the driver when it seemed he would go all the way to the stoplight at 125th Street. The driver turned just in time to screech around the corner onto La Salle. Pat sat back and said “many a flight has been caught because of this shortcut.” It saved a minute or two; we caught our flight.

On the airplane, Pat and I agreed on our pitch to management. We were both in the midst of productive research and hoped to avoid interruption. If Jastrow were to retire, either of us was willing to serve as director or interim director. Neither of us depended on Jastrow for our research, and we did not want to change our research directions. Pat did almost all of our talking. He was of Irish stock, bushy eyebrows, wavy hair, not very tall, but a strong body, as shown by his skill on the still rings (https://vimeo.com/48171442 at minute 11:18). He was articulate and enthusiastic, a burning ball of energy, as he talked about the significance of his work. He discovered numerous interstellar molecules, and with a 4-foot microwave receiver he was mapping the structure of the galaxy. Pat’s presentations were always the highlight of GISS science, but this time he added one unusual comment. He said that a Nobel Prize was likely to be given for the sort of work he was doing, and he “wouldn’t mind” getting it.112 Scientists normally would not say such a thing, even if they thought it. It made me wonder if he really wanted to be Director of GISS – but more likely he was just saying: look what you might lose if you don’t support GISS. We did not get any promises, but it was a friendly meeting. We went home with a hopeful feeling that Goddard would support us, with or without Jastrow.

The Inspector General (IG) investigation came out of the blue. The scuttlebutt, from Jastrow’s secretaries, was that a disgruntled employee at GISS filed a complaint. The complaint was that Dr. Jastrow used government resources for personal gain. Surely Dr. Jastrow had NASA approval to teach at Columbia and Dartmouth. The universities paid him well, because his classes were huge. Such outside activity, while being paid a fulltime government salary, was permissible at that time, if approved by higher management levels. However, government resources were not to be used for the outside activity. It was plain to see that Dr. Jastrow sometimes worked on lectures in the office during business hours. The university provided teaching assistants, but Dr. Jastrow also used his government support staff to assist him. This was true for his book writing, as well as his teaching. The IG documented examples, such as the government library books cut up by a government draftsman in making viewgraphs for Dr. Jastrow’s class. Were such instances incidental, a minor offense?

114 © 2020 James Edward Hansen. All Rights Reserved. The IG was impressive. He had the skills of a good lawyer and a law enforcement official. I wondered how NASA managed to keep such people. Government salaries are limited. The IG interviewed many people, including all the senior staff members. He was curious about why the other senior staff members used “Bob” in reference to Dr. Jastrow, while I always used “Dr. Jastrow.” I shrugged; I didn’t know. The IG spent a lot of time sitting in my office. I had the corner office on the 6th floor, just below Dr. Jastrow’s 7th floor office. There was a small adjoining office for my secretary, Brenda, a young Cuban-American. Brenda was out one Friday, when the IG and I were talking in my office, so Brenda’s place was taken by one of Dr. Jastrow’s several secretaries – because Jastrow insisted that my phone always be covered. The secretary, a very pleasant Chinese lady, stuck her head in the door and said “it’s Brenda – she wants to know if she can come in this weekend to use the typewriter.” Brenda was an aspiring writer, not a government employee, her salary paid via our support services contractor. I said “no, of course not.” The secretary, not too astute, was perplexed: “no means yes, right?” “No! No means no – give me the phone!” “Brenda, don’t you know we are being investigated by the IG? You cannot use a government typewriter. We have to be whiter than white!” The IG sat there the whole time with a grin on his face that went from ear to ear. Later I concluded that he was not investigating me. He already had decided that I was honest. He probably was trying to break me of any bad habits that I might have picked up.

Dr. Jastrow met with science writers occasionally. Once, in the summer of 1981, I was in Dr. Jastrow’s outer office when he was visited by Walter Sullivan, the venerable science writer for the New York Times. Dr. Jastrow introduced me as having an instrument on the Galileo Jupiter mission. Sullivan expressed interest in planetary science, so I was invited to go to lunch with them at the Moon Palace, kitty-corner across Broadway from GISS. I did not have much to say about Jupiter. I could only relate the work Makiko and I had done. We disproved John Lewis’ proposed cloud layering on Jupiter We also inferred, based on methane and ammonia absorption lines, that carbon and nitrogen were more abundant in the Jupiter atmosphere than on the Sun. However, at the last moment, as we were getting up to leave the Moon Palace, I mentioned our CO2 Science paper about to come out in Science. He expressed interest, so I said that I would mail him a copy of the paper, along with a one-page summary of conclusions that I had written with the hope of sparking interest at Goddard Public Affairs. Then I went back to my office and wrote instructions for Brenda. I still have a copy of my note – it is in the Science paper folder. In the note I asked Brenda, in addition to sending the paper and its summary to Goddard Public Affairs, to send a bcc, not a cc, of the summary and Science paper, to both Walter Sullivan and Rafe Pomerance. A bcc (blind carbon copy) meant that Goddard would receive no indication that I was also sending the paper and summary to Sullivan and Pomerance. This suggests that I realized I was violating bureaucracy procedures. Inclusion of a bcc to Pomerance is something that Rafe and I puzzled over recently. We do not remember how I knew of his possible interest and his address. It is likely that he had called me. Months earlier I had sent a draft of the paper to 30 of the most relevant scientists in the world.

115 © 2020 James Edward Hansen. All Rights Reserved. The interaction with Sullivan was my original sin. Consequences, as we will see, affected my life and the Institute for a decade. Somehow I did not learn my lesson. An analogous event decades later would have still more significant consequences.

Anniek met me at Schiphol. We stayed one night with her sister Colette’s family. Then we drove off in Colette’s car to Hamburg. Anniek says that it rained every day we were in Hamburg, but Anniek always made the best of any situation. She took Erik and Kiki to museums, while I went to meetings. When the kids doodled in the museum’s sign-in book, the hostess found a blank book and told them they could fill the book with their drawings. Hamburg was very hospitable. We did not have the opportunity to wait for Hamburg sun. I got a call from Goddard asking me to return to New York and become the Interim Director of the Goddard Institute for Space Studies. Dr. Jastrow was retiring. One problem: the cloud climatology meeting, important for our newly funded cloud research program and my main reason for being in Hamburg, had not yet occurred. Problem solved: Goddard gave emergency travel approval for Bill Rossow to come over and take my place. My career in clouds research was over; Bill took over the clouds project forever. A second problem: We had scheduled several days for one of our very infrequent vacations, to follow the Hamburg meeting. We shortened it. We took the car on a ferry to Denmark, spent one day in Copenhagen, and then drove along the Dutch delta works on the way to Leiden.

It was sunny while we were in Denmark. We walked out the hotel front door straight into Tivoli Park. We made a brief visit to the Copenhagen harbor to see the Little Mermaid on the rock overlooking the harbor. The photo I took there captures Erik and Kiki’s personalities. Seven-year-old Erik was usually cheerful, while four-year-old Kiki was often more pensive. After the long drive back to Leiden we went to a crepe restaurant on Steenstraat across the street from Beestenmarkt, the old animal market. It was a restaurant that Anniek and I had gone to when I was a post-doc in Leiden. While waiting for Kiki to finish at least half of her crepe, I doodled with a Rubik’s cube, gave up, and handed it to Erik. With his mop of hair hanging over his eyes, Erik started twisting the cube one way and another very fast. Then he handed me the completed cube. Two men in the next table watched in amazement, the one man exclaiming something in Dutch. After they left, Anniek told us what he had said: “I knew there was an easy way to solve it! Tonight I’m going to figure it out!” What they did not know was that I had brought an article with a prescription for solving the cube. Erik and I each succeeded in memorizing it in rainy Hamburg, but I had forgot a step. Erik could do it faster than I could – my excuse was that his small fingers were more dexterous. I left the family behind the next morning and headed for New York. If I had realized the reception that was waiting, I would not have been so eager.

116 © 2020 James Edward Hansen. All Rights Reserved.

1 The LDS movement arose during an early 19th century period of Protestant religious revival, which some scholars relate to rejection of the rationalism of the Enlightenment or Age of Science and Reason. I believe it indicates that science and reason alone do not satisfy the need of many people for a spirituality that provides strength and helps give meaning to their lives. Joseph Smith founded the LDS movement in western New York after he had visions in which Smith claimed God instructed him not to join any of the existing churches. Smith said that an angel showed him the location of golden plates with writing that he translated, with divine assistance, to a new sacred text, the Book of Mormon, which he published in 1830 as a complement to the Bible. As Smith’s following grew, local opposition forced repeated moves of the group, eventually to a small town in Illinois that they named Nauvoo. Nauvoo’s population reached a peak of about 14,000 rivaling that of Chicago, but renewed tensions with non- Mormons resulted in the murder of Joseph Smith by a mob in 1844. The largest group of Mormons accepted Brigham Young as the new prophet and leader and emigrated with him to the Utah Territory. Under Young the LDS Church openly practiced polygyny, which Smith had instituted in Nauvoo. The LDS Church officially ended plural marriage in 1890, and today members who practice it are excommunicated. The LDS Church has extended its reach internationally via a vigorous missionary program, growing to a membership of about 15 million. 2 The RLDS church changed its name to Community of Christ in 2001. It reports about 250,000 members today. 3 Abraham Galland was the first white settler in Shelby County, building a log cabin in Gallands Grove in 1847. 4 The Hansen Family, C.S. Stene and D.H. Stene, 389 pp., Library of Congress CCN:2009902650, 2009. 5 History of Harrison County, Iowa : its people, industries and institutions, with biographical sketches of representative citizens and genealogical records of many of the old families 6 Soares, P., L. Ermini, N. Thomson, M. Mormina, T. Rito, A. Rohl, A. Salas, S. Oppenheimer, V. Macaulay, and M.B. Richards, Correcting for purifying selection: an improved human mitochondrial molecular clock, Amer. J. Human Genetics, 2009; doi:10.1016/j.ajhg.2009.05.001. 7 Rutherford, A., A Brief History of Everyone Who Ever Lived, Orion, 2016. 8 Wilson, E.O., Half-Earth: Our Planet’s Fight for Life, Liveright Publ. Corp., 272 pp., 2016. 9 Surviving After the Great Depression, Eleanor Hansen Maiefski, 62 pages, unpublished. 10 Prairie Fires: The American Dreams of Laura Ingalls Wilder, Caroline Fraser, Henry Holt & Co, 641 pp., 2017. 11 The Des Moines Lobe of the last great glacier, 20,000 years ago, skirted the northeast corner of Crawford County. The Denison hill may have been formed by one of the earlier glaciers. Surface soil, in the Southern Iowa Drift Plain, originated from glacial action at different periods in geologic time, and may include some of the loess that forms thick dunes closer to the Missouri River. 12 Abraham Lincoln was granted 40 acres for ‘fighting’ in the Black Hawk War, which some would describe as a massacre, not a war. Lincoln never raised a rifle, but he was conscripted. Lincoln’s 40 acres were on the edge of Denison, on Vernon Voss road, just down the road from my mother’s final home. Lincoln never set foot in Denison, but there is a marker (photo here) on what was his property. 13 Lokken, Roscoe L., Iowa Public Land Disposal, Historical Society of Iowa, Iowa City, 318 pp., 1942. 14 Denison Bulletin, Denison Centennial 1856-1956, page 2, 24 August 1956. 15 For context, the judge’s full paragraph read: “Plaintiff says defendant was morose, sullen, did not speak for days at a time and that at such times he refused to eat with the family. There is some foundation for this. It does appear that when defendant disapproved of his wife he withdrew to himself. His disapproval was always due to his dislike of her night work. It is natural that a man, traditionally the supporter of the family, should be displeased and chagrined at the wife’s doing what he should do. Defendant evidently did not adapt himself to the family situation, and did not demonstrate his displeasure in the usual way.” 16 Maharidge, D., Denison, Iowa, Free Press, Simon & Schuster, New York, 260 pages. Anti-German feelings and actions, which Denison prefers to forget, seem to have disappeared by the time I was growing up. 17 Prof. Van Allen had a Geiger counter on , the first U.S. satellite, launched 31 January 1958, for the purpose of measuring cosmic rays, energetic electrically charged particles. Such charged particles are continuously emitted by the Sun, carried outward in a “solar wind.” Van Allen’s instrument found that a large amount of these charged particles were temporarily trapped by Earth’s magnetic field in large donut-shaped “belts” encircling Earth, that now bear Van Allen’s name. 18 Link, F.: Die Mondfinsternisse, Leipzig, Akademische Verlagsgesellschaft, Geest & Portig, 127 pages, 1956. 19 Hansen, J.E. and S. Matsushima: Light Illuminance and Color in Earth’s Shadow, J. Geophys. Res., 71, 1073- 1081, 1966. 20 Water vapor (H2O) and carbon dioxide (CO2) absorb heat radiation from Earth’s surface, so they serve as a ‘blanket’ keeping the surface warmer than it would be without the gases. H2O is the stronger absorber on Earth, where the ocean provides a nearly limitless supply, but H2O is condensable, so the amount in the air depends on temperature. Thus CO2 is the ‘control knob’ that determines the amount of atmospheric H2O and global temperature.

117 © 2020 James Edward Hansen. All Rights Reserved.

21 Thus a 100-watt light bulb emits 1000 times more energy, as heat and light, than 0.1 watt. Averaged over the entire Earth’s surface, day and night, Earth absorbs about 240 watts per square meter of solar energy, so the flow of energy from Earth’s interior is much less than one-tenth of one percent of solar energy absorbed by Earth. 22 The National Research Council of the National Academy of Sciences administers post-doc positions for NASA. The National Academy of Sciences was formed during the Civil War, in 1863, to advise the U.S. government on scientific and technical issues. The National Research Council was formed by NAS in 1916, as war was threatening, to spur research cooperation among academia, industry and government to promote national security and welfare. 23 https://vimeo.com/48171442 24 The energy change is due to flip of the spins of the proton and electron between parallel and anti-parallel states. 25 Van de Hulst, H.C., Light Scattering by Small Particles, John Wiley & Sons, New York, 470 pp., 1957. 26 Maser and laser are microwave and light amplification by stimulated emission of radiation. https://en.wikipedia.org/wiki/Maser 27 Thaddeus, P., The dry massive model of the atmosphere of Venus and the microwave phase effect, in J.C. Brandt and M.B. McElroy, The Atmospheres of Venus and Mars, Gordon and Breach, 288 pp., 1968. 28 Davidson, Keay, Carl Sagan, John Wiley & Sons, 540 pp., 1999. 29 Poundstone, William, Carl Sagan, Henry Holt & Co., 473 pp., 1999. 30 Sagan C. and J. B. Pollack, Anisotropic nonconservative scattering and the clouds of Venus, J. Geophys. Res. 72, 469, 1967. 31 The daggerboard is the retractable centerboard. Its function is to give the boat stability, and the shape of the daggerboard converts the boat’s forward motion into a windward lift that counters the leeward push of the sail. 32 Hansen, J.E., Absorption-line formation in a scattering planetary atmosphere: A test of Van de Hulst's similarity relations. Astrophys. J., 158, 337-349, 1969. 33 The Pilgrims, of English extraction and Puritan Calvinist faith, emigrated from England to Leiden to escape from the volatile political environment in England to the tolerance of 17th century Holland. Fearing that they may lose their English cultural identity, they arranged with English investors to establish a new colony in North America. 34 It was a memorable meeting, as the streets were patrolled by machine-gun-toting Russian soldiers. The Warsaw Pact nations invaded Czechoslovakia in August 1968 to crush the Prague Spring of Alexander Dubček 35 The ‘blanket’ analogy for greenhouse gas warming is imperfect, as is the analogy to a greenhouse or to an automobile with windows rolled up. A blanket and windows are effective mainly in blocking heat transfer by convection and conduction. A planet gains and loses heat only via radiation – by absorbing incoming sunlight and emitting heat radiation, the latter being partially blocked by greenhouse gases. 36 My recollection differs a bit from that of Steve in his book Science as a Contact Sport (National Geographic Society, 295 pp., 2009, ISBN: 978-1-4262-0540-8). Although my memory of events half a century ago may not be exact, I still have a copy of the Mie aerosol computations that I gave to both Steve and Ichtiaque, so that part is right. The photo of us on page 18 of Steve’s book, described there as circa 1971, is actually circa 1990. 37Rasool, S.I. and S.H. Schneider, Atmospheric carbon dioxide and aerosols: effects of large increases on global climate, Science, 173, 138-141, 1971. 38 Charlson, R.J. and M.J. Pilat, Climate: the influence of aerosols, J. Applied Meteorol., 8, 1001-1002, 1969. 39 Albedo literally means ‘whiteness.’ The albedo of a particle is the fraction of light hitting the particle that is scattered, the remaining fraction being absorbed by the particle. The albedo of an atmospheric layer is the fraction on sunlight impinging on the layer that would be reflected back if the layer were isolated in space, the remaining fraction of incident light is absorbed by the layer or transmitted through the layer. 40 If each successive reflection of light has x times the energy of the prior reflection, the sum from all reflections is sum = 1/(1 ̶ x). For example, if x = 0.5, the sum of 1 + 0.5 + 0.25 + 0.125 + … is 2. 41 Schneider, S.H., A comment on “Climate: the influence of aerosols”, J. Appl. Meteorol., 10, 840-841, 1971. 42 Are We Winning the War Against Air Pollution? See http://www.realclimate.org/images/schneider_letter_1971.jpg 43 Rich, N., Losing Earth, the decade we almost stopped climate change, New York Times Magazine, 5 August 2018. 44 Irradiance is the flux of radiant energy per unit area normal to the direction of radiation flow. 45 The law says energy radiated from a surface is proportional to the 4th power of its absolute temperature, with temperature measured in degrees Kelvin (Kelvin temperature in degrees is Celsius temperature plus 273). 46 Tyndall, J., Radiant Heat, Longmans, Green, and Co., London, 1872 (available: https://archive.org/stream/contributionsto01tyndgoog#page/n441/mode/1up). 47 Pollack, J.B., Toon, O.B. and Boese, R., Greenhouse models of Venus’ high surface temperature, as constrained by Pioneer Venus measurements, J. Geophys. Res., 85, A13, 8223-8231, 1980. 48 Beerling, D.J., J.R. Leake, S.P. Long, J.D. Scholes, J. Ton, P.N. Nelson, M. Bird, E. Kantzas, L.L. Taylor, B. Sarkar, M. Kelland, E. DeLucia, I. Kantola, C. Muller, G.H. Rau and J. Hansen, 2018: Farming with crops and rocks to address global climate, food and soil security, Nature Plants, 4, 138-147, doi: 10.1038/s41477-018-0108-y. 49 McElroy, M.B., M.J. Prather and J. Rodriquez, Escape of hydrogen from Venus, Science 215, 1614-1615, 1982. 50 Sagan, C., The radiation balance of Venus, Cal Tech JPL Tech. Rept. 32-34, 23 pp., 1960. 118 © 2020 James Edward Hansen. All Rights Reserved.

51 Gold, T., Outgassing processes on the moon and Venus, in The Origin and Evolution of Atmospheres and Oceans, Eds. Brancazio & Cameron, New York, Wiley, 249-256, 1964. 52 Ingersoll, A.P., The runaway greenhouse: a history of water on Venus, J. Atmos. Sci., 26, 1191-1198, 1969. 53 Hansen, J., M. Sato, G. Russell and P. Kharecha, Climate sensitivity, sea level and atmospheric carbon dioxide, Phil. Trans. Roy. Soc. A. 371, 20120294, 2013; see Figure 7. 54 Solar irradiance at Earth averaged over the year is about 1361 W/m2, but this is reduced by a factor of four when averaged over Earth’s surface area, and only about 70 percent of the incident radiation is absorbed. 55 The unit of atmospheric pressure used in this sentence, millibars (mb), is still preferred by many weather forecasters and old scientists, while scientific journals now use hectopascals (hPa). 1 hPa is the same as 1 mb. Average surface pressure on Earth is 1.013 bars = 1013 millibars = 1013 hPa. 56 Sackmann, I.J., A. Boothroyd, and K. Kraemer, Our sun III: present and future, Astrophys. J. 418, 457-468, 1993. 57 Jastrow, R., Red Giants and White Dwarfs, Warner Books, 275 pp., 1979. Red giants and white dwarfs refer to later phases in the life cycle of stars, including our Sun, that have an initial mass similar to that of the Sun. 58 Platzman, G.W.: The ENIAC computations of 1950 – gateway to numerical weather prediction, Bull. Amer. Meteorol. Soc. 60, 302-312, 1979. 59 The easiest way to stabilize a spacecraft is to set it spinning. A simple telescope on a spinning spacecraft can acquire one line of data as the telescope’s field of view scans across the planet. Successive scans as the spacecraft orbits the planet can build up an image of the planet. 60 Crutzen showed a year earlier (Crutzen, P.J.: The influence of nitrogen oxides on the atmospheric ozone content, Quart. J. Roy. Meteorol. Soc., 96, 320-325, 1970) that nitrous oxide, N2O, produced by fertilizers reaches the stratosphere, where, after conversion to NO, it depletes stratospheric ozone. References re SSTs: Crutzen, P.J.: SST’s – A threat to the Earth’s ozone shield, Ambio, 1, 41-51, 1972. Johnston, H.: Reduction of stratospheric ozone by nitrogen oxide catalysis from supersonic transport exhaust, Science, 173, 517-522, 1971. 61 McElroy, M.B., Wofsy, S.C., Penner, J.E. and McConnell, J.C.: Atmospheric ozone: possible impact of stratospheric aviation, J. Atmos. Sci., 31, 287-303, 1974. 62 Molina, M.J. and Rowland, F.S.: Stratospheric sink for chlorofluoromethanes: chlorine atom catalyzed destruction of ozone, Nature, 249, 810-812, 1974. 63 CFCl3 and CF2Cl2, with trade names CFC-11 and CFC-12, popularly called Freons, are a product of Dupont Chemical (now Chemours). CFCs were used mainly in refrigeration and as propellants in spray cans, hair sprays and deodorants, for example. 64 Hansen, J., M. Sato and R. Ruedy, Radiative forcing and climate response, J. Geophy. Res., 102, D6, 6831-6864, 1997. 65 Somerville, R.S. et al., The GISS model of the global atmosphere, J. Atmos. Sci., 31, 84-117, 1974. 66 Lacis, A.A. and J.E. Hansen, A parameterization for the absorption of solar radiation in the Earth’s atmosphere, J. Atmos. Sci., 31, 118133, 1974. 67 If the horizontal resolution increases by a factor of two, there are 2×2 = 4 boxes within the prior larger box. In addition the model’s time step, which is proportional to the time required for the wind to blow across the box, must be decreased by the factor 2. 68 Ramanathan, V., Greenhouse effect due to chlorofluorocarbons: climatic implications, Science, 190, 50-52, 1975. 69 World Meteorological Org., The physical basis of climate and climate modeling, GARP Publ. Ser. No. 16, 1975. 70 Wang, W.C., Y.L. Yung, A.A. Lacis, T. Mo and J.E. Hansen, Greenhouse effects due to man-made perturbations of trace gases, Science, 194, 685-690, 1976. 71 A native Iowan, Cooper grew up in Cedar Rapids and received his first degree from the University of Iowa in electrical engineering (B.S.E.E.). His Sc.D. degree was in electrical engineering from MIT, where he taught for several years before joining the Department of Defense. 72 By Goddard, I refer to GSFC; by GISS or the Institute, I refer to the Goddard Institute for Space Studies. 73 Sato, M. and J.E. Hansen: Jupiter's atmospheric composition and cloud structure deduced from absorption bands in reflected sunlight. J. Atmos. Sci., 36, 1133-1167, 1979. 74 Hansen, J.: End of the Rainbow, upcoming book on space missions to Earth and other planets. 75 Hunten, D.M., L. Colin, and J.E. Hansen: Atmospheric science on the Galileo mission. Space Sci. Rev., 44, 191- 240, 1986. 76 “Dr. Hansen is an outstanding scientist and highly regarded by leaders in his field, such as Drs. Hunten and Richard Goody, for his critical judgment, clarity of thought, originality, and ability to focus on major problems. Although trained as a theorist, he has become highly competent in experimental work, as manifested by his selection as PI or co-PI on several planetary flight experiments. He shares the unusual rare quality of combined theoretical and experimental talent with the other leading scientist at GISS, Patrick Thaddeus, and with exceptional first-rank scientists in the university community such as Charles Townes.” 77 “Dr. Hansen was completely new to climate work a year ago. In the relatively short intervening period he has mastered the difficult field of atmospheric modeling and has been given a prominent role in Center and Agency planning for a climate program. His research contributions119 to the NASA flight program have already been © 2020 James Edward Hansen. All Rights Reserved. mentioned. Dr. Hansen has demonstrated unusual administrative ability in handling the climate project at GISS, and is very competently managing the GISS budget as a whole. In addition, he is highly regarded by our colleagues at Columbia University and functions as the principal GISS representative to the Columbia Geology Department.” 78 Renee Skelton, Forecast Earth – the story of climate scientist Inez Fung, Joseph Henry Press, Washington, 2005. 79 Fung, I.: In Pursuit (biography), Annual Review of Earth and Planetary Sciences, 48, 1-20, 2020. 80 Graduate study in a physics department is a good background for a career in Earth sciences, especially if the physics department will allow substitution of a small number of courses in geological sciences for advanced physics courses. Columbia Physics and Astronomy Department rebuffed my suggestion for that option. 81 Fourier, J., Remarques generals sur les temperatures du globe terrestre et des espaces planetaires, Annal Chim. Phys., 27, 136-167, 1824. 82 The blanket analogy, is imperfect, as are the “greenhouse” and “automobile with windows rolled up” analogies, which include limitation of heat transfer by other processes such as conduction and convection (see Chapter 10). 83 Eunice Foote was on the editorial committee for the 1848 Seneca Falls Convention, the first women’s rights convention, and she helped prepare the proceedings for publication. 84 Foote, E.: Circumstances affecting the heat of the Sun’s rays, Amer. J. Sci. Arts, 22, 382-383, 1856. 85 Increasing atmospheric CO2 slightly increases absorption of sunlight by Earth, but it reduces the amount of sunlight reaching the ground and surface air. The efficacy of climate forcings is greatest if the forcing occurs at or near Earth’s surface (Hansen, J., M. Sato, and R. Ruedy, 1997: Radiative forcing and climate response. J. Geophys. Res., 102, 6831-6864, 1997; Hansen, J. et al.: Efficacy of climate forcings. J. Geophys. Res. 110, D18104, 2005). Whether absorption of sunlight by CO2 causes global warming or global cooling cannot be answered with a 1-D or toy climate model; the effect on the vertical temperature profile requires proper treatment of moist and dry convection in a 3-D global model. 86 The Royal Society, perhaps in penitence for the long history of male chauvinism in science, published an article (Jackson, R.: Eunice Foote, John Tyndall and a question of priority, Notes and Records of the Royal Society, 74, 105-118, 2020) full of innuendos of a male conspiracy to rob Foote of rightful priority for discovery of the infrared greenhouse effect of CO2. In fact, she did not investigate the greenhouse effect, nor could others use her data for that purpose. Her data in “the shade,” a control for the measurements in sunlight, included effects of diffuse sunlight, thermal emission, and other factors, making it indecipherable for that purpose. The Jackson article was preceded by and followed by articles in popular media with accusations, such as: McNeill, L.: This lady scientist defined the greenhouse effect but didn’t get the credit, because sexism, Smithsonian Magazine, 5 December 2016. In fact, she did not investigate the greenhouse effect nor pretend to; there is no merit in so mischaracterizing her impressive scientific contributions. 87 Tyndall, J.: Radiant Heat, Longmans, Green, and Co., London, 1872 (available https://archive.org/stream/contributionsto01tyndgoog#page/n441/mode/1up). 88 Tyndall, J., On the absorption and radiation of heat by gases and vapours, Phil. Mag, 22, 169-194, 273-285, 1861. 89 Fleming, J.R., Historical perspectives on climate change, Oxford University Press, 1998; quoted by Hulme, M., On the origin of ‘the greenhouse effect’: John Tyndall’s 1859 interrogation of nature, Weather, 64, 121-123, 2009. 90 Arrhenius, S.: On the influence of carbonic acid in the air upon the temperature of the ground, Phil. Mag., Ser. 5, Vol. 41, No. 251, 237-276, 1896. 91 Arrhenius, S.: Worlds in the Making: The Evolution of the Universe, Harper & Brothers; freely available: https://archive.org/details/worldsinmakingev00arrhuoft, 1908. 92 Angstrom, K.: Ueber die bedeutung des wasserdampfes und der kohlensaure bei der absorption der Erdatmosphare, Annalen der Physik, 308, 720-732, 1900. 93 Callendar, G.S.: The artificial production of carbon dioxide and its influence on temperature, Quar. J. Roy. Meteorol. Soc., 64, 223-240, 1938. 94 Forestner, A.: James Van Allen:The First Eight Billion Miles, p. 124, University of Iowa Press, 322 pp., 2007. 95 Discovery of this mountain chain, the largest on Earth, encircling the globe provided critical information confirming the concept of ‘continental drift.’ The theory of plate tectonics, that Earth’s outer shell is divided into several plates that glide over Earth’s mantle, the more fluid rocky layer above Earth’s core, was soon developed. 96 Revelle, R. and Suess, H.E.: Carbon dioxide exchange between atmosphere and ocean and the question of an increase of atmospheric CO2 during the past decades, Tellus IX, 18-27, 1957. 97 Bolin, B. and E. Eriksson: Changes in the carbon dioxide content of the atmosphere and sea due to fossil fuel combustion, in The Atmosphere and Sea in Motion, Rossby Memorial Volume, Rockefeller Institute Press, 1959. 98 Wally died when this book was nearly finished. I will remember him as the scientist who had the greatest impact on the science – he was the straw who stirred the climate change drink and the great grandfather of global warming. 99 PSAC: Restoring the Quality of Our Environment, Report of Environmental Pollution Panel, White House, 1965. 100 Revelle, R., et al, Appendix Y4 to PSAC: Atmospheric Carbon Dioxide, pp. 111-133, 1965. 101 Manabe, S., Smagorinsky, J. and Strickler, R.F.: Simulated climatology of a general circulation model with a hydrologic cycle, Mon. Wea. Rev., 93, 769-798, 1967. 120 © 2020 James Edward Hansen. All Rights Reserved.

102 Manabe, S. and Wetherald, R.T.: The effects of doubling the CO2 concentration on the climate of a general circulation model, J. Atmos. Sci., 32, 3-15, 1975. 103 Manabe, S. and Bryan, K.: Climate calculation with a combined ocean-atmosphere model, J. Atmos. Sci., 26, 786-789, 1969. 104 Lorenz, E.N., Irregularity: A fundamental property of the atmosphere, Tellus Ser. A, 36, 98-110, 1984. 105 Solar irradiance at Earth averaged over the year is about 1361 W/m2, but this is reduced by a factor of four when averaged over Earth’s surface area, and only about 70 percent of the incident radiation is absorbed. 106 Hansen, J.E., W.-C. Wang, and A.A. Lacis: Mount Agung eruption provides test of a global climatic perturbation. Science, 199, 1065-1068, 1978. 107 Charney, J., Arakawa, A., Baker, D., Bolin, B., Dickinson, R., Goody, R., Leith, C., Stommel, H., and Wunsch, C.: Carbon Dioxide and Climate: A Scientific Assessment, Natl. Acad. Sci. Press, Washington, DC, 33p, 1979. 108 Conventional definition of the uncertainty range given by the number after “±” is 95 percent confidence that the true answer falls in that range. IPCC, however, uses 90 percent confidence and Charney used 50 perent. 109 Understanding Climatic Change, National Academy of Sciences, Washington, 239 pp., ISBN 0-309-02323-8. 110 I sent the first draft of the paper to 30 of the most relevant experts. Charney had a positive reaction and said that the paper was a good complement to his report. In my reply to Charney I asked him to put in a word with Abelson. 111 Hansen, J., D. Johnson, A. Lacis, S. Lebedeff, P. Lee, D. Rind, and G. Russell: Climate impact of increasing atmospheric carbon dioxide. Science, 213, 957-966, 1981. 112 Pat never got the Nobel, even though one was given for satellite measurements of the cosmic microwave background radiation, a project that was hatched in Pat’s office with Pat as an intellectual leader. Pat arguably could have been given a Nobel for his remarkable work in mapping the Milky Way with his small microwave telescope.

121 © 2020 James Edward Hansen. All Rights Reserved.