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10 OUR CHANGING WORLD, Thursday, January 12, 2006, Bangor Daily News

Continued from Page 4 kind of evidence telling the whole long before our cities were built and ice age, a period of alternating Four times over the past 500 mil- story,” Jacobson said. Only from all that very likely will happen again. warm and cool phases that began lenniums, ice has advanced, as Today, climate is the provenance these stories from ice cores, lake sedi- And once the natural systems are 2½ million years ago. though on a regular schedule. The of scientists, not philosophers, ments, fossils, tree rings, coral reefs, defined, the role that we play in trans- “We’re still in the ice age, and most recent glaciation, which ended although this gumbo of disciplines rocky cliffs and even old diaries will a forming the climate will become clear, most people don’t know what the ice between 12,000 and 17,000 years ago, — incorporating geology, biology, full picture of the past emerge. Jacobson said. age is,” Borns said. formed Maine’s landscape. Glaciers oceanography, chemistry and, “The data becomes so diffuse and “It’s only in understanding the The woolly mammoths that scraped over the rocky ground, increasingly, social sciences such as broad and plentiful that one person natural variability that we can see once marched over the sheets of chiseling the peaks and valleys of history and archaeology — requires can’t handle it all,” said Hal Borns, what’s happening today,” he said. ice atop what is now Bangor are Baxter State Park and the White more than a little faith. founder of the multidisciplinary Cli- long gone, but millions of years of Mountains. Mayewski travels the world, sav- mate Change Institute. ‘We’re still in the ice age’ climate data indicate that the Then, as the ice receded, melting ing ice cores from rapidly melting “All the knowledge just can’t be Mainers joke about the brevity of a world may be poised on the edge water rushed over the land, leav- glaciers in hopes that they can locked up in one or two people,” New England summer, claiming that of the next glaciation, or cool ing long, narrow deposits of sand reveal the history of the world. Borns said. all they have to do is blink once and phase of the ice age. Of course, to and gravel that snake across the Other scientists hunt messages in At the University of Maine, one of the snow is falling again. But warm climate scientists, who think on state. rock formations. Jacobson seeks several centers for climate research periods of time in which the state mind-boggling time scales, that “Over a period of just 4,000 or knowledge in ancient pollen around the country, scientists are experiences anything that can be edge could last for many human 5,000 years, there was an incredibly trapped far beneath lake waters. piecing together the history of the called a summer have been tremen- generations. rapid change from Maine being cov- Each believes that the information natural world in hopes of someday dously rare — just 10,000 years of “Some people say we’re 500 to 1,000 ered by ice to being covered by for- is there, waiting to be tapped. being able to predict the sorts of dras- heat for every 100,000 years of snow. years overdue,” Borns said. “We’ve est,” Jacobson said. “It’s not a simple matter of one tic changes that affected the planet Earth is still in the throes of an been through the warm spell.” Continued on Page 11

Changes in temperature, salinity, currents mean ripple effects elsewhere When the wind starts to blow and nor’easters to Maine are also at the rain starts to fall, most people don’t the whims of global climate. blame the oceans for their plight. Currents are put in motion by But the waters that cover more than cold water sinking to the sea bot- 70 percent of Earth’s surface are inti- tom in the polar regions because mately linked to the planet’s climate. it becomes more dense and holds “Many people think climate is the more salt as it loses its heat to weather. In fact, the ocean is the the air. The cold water moves largest driver of climate,” said Fei downhill along the sea bottom Chai, an oceanographer with the Cli- toward the equator, where it mate Change Institute at the Universi- warms and returns to the sur- ty of Maine. face. Prevailing winds then In the real world, the oceans and the drive the warm surface water atmosphere lack the distinct boundary back toward the poles. The lines depicted in textbooks. Water, car- result is continual motion bon dioxide, oxygen and other mole- throughout the oceans. cules constantly travel back and forth This system was dubbed “the between the air and the sea. great conveyor belt” by climatol- Most coastal residents understand ogist Wallace Broecker of the how the oceans help to moderate tem- Lamont-Doherty Earth Obser- perature by warming or cooling vatory at Columbia University, Arctic Ocean breezes that pass over the water en because it drives much of the route to land. world’s weather. Scientists cite The oceans play a similar role on a changes in the circulation pat- global scale. The sea can absorb or tern as a major factor in past ice Pacific release a tremendous amount of ages. The system has been rela- Ocean heat, slowing the impact of a climate tively stable for the past 200-300 Atlantic shift. years, after likely playing a role Ocean The oceans also hold a great deal of in the cold phase known as the nt urre carbon dioxide, one of the most abun- Little Ice Age between the 14th Indian ce c urfa Ocean m s dant greenhouse gases. Carbon is pres- and 19th centuries. Heat released War ent in all living things — including But if Earth becomes too to the atmosphere plankton and the calcium carbonate warm, millions of gallons of structure of clams and corals — which fresh water from melting polar gla- will eventually decompose, creating ciers and icebergs could pour into Cold saline more carbon dioxide. the sea, interfering with the tem- rrent Deep cold cu deep current “A cooler ocean tends to hold carbon perature and salt balance, or ther- dioxide — like a can of Coke,” Chai mohaline, that maintains the cur- explained. “When you have warmer rents. aline circulation r Belt: Thermoh nd Earth through a water, the CO2 starts bubbling out of “The ocean transports a lot of t Ocean Conveyo yor” moves heat arou d salt Grea known as the “conve ifferences in heat an the water into the air. heat from the western side of the n circulation pattern s primarily driven by d w-salini- An ocea ement of ocean water e” for salt.) Warm, lo interconnected mov rm” for heat and “halin f this This is just one of the many climate Atlantic to the eastern side,” Chai globally aline circulation (“the r (red path). Cooling o nt known as thermoh ntic, becoming saltie d flow phenomena that concern scientists, said. conte the surface of the Atla r the water to sink an ater, flo ws north along h enough densities fo nd the like Chai, who produce models predict- Without this conveyor belt, the ty w Atlantic produces hig ). If Arctic ice melts a r water in the North cean basins (blue path ts specu- ing what might happen if the climate Gulf Stream, which carries warm saltie cean and into other o er sink. Some scientis uthward in the deep o alty, they will no long peratures so row warmer and less s am and dropping tem changes. For example, high levels of water to the United States and West- rth Atlantic waters g , slowing the Gulf Stre No t suddenly shut down CO2 in the atmosphere could warm ern Europe, could weaken or change te the conveyor migh st United States. la rope and the Northea the oceans, prompting the release of path. significantly across Eu still more CO2 and spurring further Broecker and some other scientists warming. believe they have evidence from ice University of Maine And as Hurricane Katrina so aptly cores that suggests that this system To better understand, and predict, 256 high-powered PCs, showing how oceanographer Dr. Fei demonstrated, warm oceans also can has changed in the past, bringing ice the behavior of these systems, scien- the oceans change over time, their Chai (left) and Professor Huijie Xue (seated) trigger more immediate effects. Mon- and snow to the temperate regions. tists have deployed a small army of warm and cold currents strengthening explain an ocean circula- ster storms will happen occasionally The disaster movie “The Day After buoys and free-swimming rovers to and dissipating. tion model they have in any climate, but warmer water has Tomorrow” was based on Broecker’s monitor the high seas, transmitting Internationally, the goal is someday extrapolated from a the potential to breed more ferocious theory — albeit in a dramatically exag- their data by satellite. to have thousands of live data collec- dozen remote moorings hurricanes. gerated form that depicted the start of Chai uses this and historical climate tors, drifting in all of the world’s with cell phone and The ocean currents that bring mon- a new ice age in Manhattan over a data to create complex models on a oceans, searching for the signals that satellite uplinks from the Gulf of Maine. Next to soons to India, El Ninos to Peru, and period of a few days. supercomputer with the capability of the climate is beginning to change. them is research associ- ate Steve Cousins and post-doctoral researcher Masa Fujii. IMPACT: LITTLE ICE AGE Course of American history shaped by mysterious deep freeze

Every year, schoolchildren hear encased in ice despite the frantic the tale of George Washington and prayers of clergy. his band of barefoot soldiers in In the North Atlantic, the Vikings ragged clothes huddled in the blood- abandoned centuries of expansion stained snow near the Delaware into Greenland, Iceland, Atlantic River during the bitter winter of Canada and possibly even New Eng- 1777. Today, Chester County in land when colder weather brought Pennsylvania, where Valley Forge is sea ice into their shipping lanes and located, is known for its mild win- made their journeys increasingly ters, averaging only about 3 feet of perilous. snow over the course of a year. In the United States, the The drastic difference isn’t evi- onslaught of cold and drought was dence of global warming. Rather, it likely a factor in “lost” 16th and shows a historical climate shift that 17th century British colonies at helped shape the course of Ameri- Popham Beach in Maine and can history. The years between 1300 Roanoke Island in North Carolina. e, dated unt map of Fort St. Georg and about 1850 are known as “the Ice cores and historical accounts The John H olony. er 8, 1607, Popham Bay c “Washington and La Little Ice Age,” years in which tem- reveal that temperatures through- Octob fayette at Valley Forge” peratures were, on average, much out the temperate regions dropped colder than today. significantly within just a few Age has attracted extensive study. dictable weather affected at least the Crops failed across Europe, con- stormy years. In 1315 alone, thou- “It happened within historic entire Northern Hemisphere and tributing to political and social sands died when wild storms her- time, the data sets are good, [and] it perhaps the whole world. But many overlapped to cause the deep freeze. strains that led to the French Revo- alded the start of the Little Ice Age, was severe for humans,” said Hal questions remain about the cause. Some even argue that the Little Ice lution and the potato famine in Ire- bringing widespread famine to Borns of the University of Maine Some point to a dearth of Age might have continued to the land. In the Alps, advancing glaciers Europe. Climate Change Institute. sunspots as the primary cause of present day, if not for the climate- swallowed up entire villages, includ- As the most recent example of Climatologists now know that the Little Ice Age. Others theorize changing impact of the Industrial ing a famous chapel that was drastic climate shifts, the Little Ice this shift to colder, often less pre- that different natural climate cycles Revolution.

1932 1947 1962 1970 1980 1982 Geologist W.J. A team of scientists at the University of Bangor is snowbound as the The United States Mount St. Helens erupts The world's climate is affected Humphreys introduces Chicago develops radiocarbon dating, a year ends with a storm that celebrates its first in Washington state, by a particularly dramatic El the idea that Earth's cli- technique for determining the age of any delivers 20-foot drifts. The Earth Day, the sym- sending ash around the Nino event. This ocean circula- mate is not stable and organic item, such as a fossilized plant or biggest snowstorm in recent bolic start of the world over the course of tion pattern named for the that an ice age could a human bone, by measuring how its con- memory, the Blizzard of '62 modern environmen- a month. Neighboring Christ child tends to occur return. "We are not stituent carbon has changed with time. cripples the city, reducing tal movement, which Idaho and Montana every four to 12 years, bring- wholly safe from such a The technique can accurately date items as I-95 to a single lane and helps to shift the briefly experience drastic ing drought to eastern world catastrophe," he old as 50,000 years, and made paleobotany stranding more than 600 discussion of climate temperature decreases Australia and Indonesia and wrote. a key element of understanding past cli- people in a local restaurant. change from acade- because of ash and dust heavy rains to western South mate shifts. mia to the public. in the atmosphere. and Central America.