Revisiting the Limits to Growth After Peak Oil

In the 1970s a rising world population and the finite resources available to support it were hot topics. Interest faded—but it’s time to take another look

Charles A. S. Hall and John W. Day, Jr.

n recent decades there has been con- strongly influenced by the writings tainable future,” but the word “energy” Isiderable discussion in academia of ecologists and computer scientists appeared only for personal “creative and the media about the environmen- who spoke clearly and eloquently energy”—and “resources” and “human tal impacts of human activity, especial- about the growing collision between population” were barely mentioned. ly those related to climate change and increasing numbers of people—and But has the limits-to-growth theory biodiversity, but far less attention has their enormously increasing material failed? Even before the financial collapse been paid to the diminishing resource needs—and the finite resources of the in 2008, recent newspapers were brim- base for humans. Despite our inatten- planet. The oil-price shocks and long ming with stories about energy- and tion, resource depletion and popula- lines at gasoline stations in the 1970s food-price increases, widespread hun- tion growth have been continuing re- confirmed in the minds of many that ger and associated riots in many cities, lentlessly. The most immediate of these the basic arguments of these research- and various material shortages. Subse- issues appears to be a decline in oil ers were correct and that humans were quently, the headlines have shifted to the reservoirs, a phenomenon commonly facing some sort of limits to growth. It collapse of banking systems, increasing referred to as “peak oil” because global was extremely clear to us then that the unemployment and inflation, and gen- production appears to have reached growth culture of the American econ- eral economic shrinkage. A number of a maximum and is now declining. omy had limits imposed by nature, people blamed at least a substantial part However, a set of related resource such that, for example, the first author of the current economic chaos on oil- and economic issues are continuing made very conservative retirement price increases earlier in 2008. to come home to roost in ever greater plans in 1970 based on his estimate Although many continue to dismiss numbers and impacts—so much so that we would be experiencing the ef- what those researchers in the 1970s that author Richard Heinberg speaks fects of peak oil just about the time of wrote, there is growing evidence that of “peak everything.” We believe that his expected retirement in 2008. the original “Cassandras” were right on these issues were set out well and basi- These ideas have stayed with us, even the mark in their general assessments, cally accurately by a series of scien- though they largely disappeared, at least if not always in the details or exact tim- tists in the middle of the last century until very recently, from most public dis- ing, about the dangers of the continued and that events are demonstrating that cussion, newspaper analyses and college growth of human population and their their original ideas were mostly sound. curricula. Our general feeling is that few increasing levels of consumption in a Many of these ideas were spelled out people think about these issues today, world approaching very real material explictly in a landmark book called The but even most of those who do so be- constraints. It is time to reconsider those Limits to Growth, published in 1972. lieve that technology and market eco- arguments in light of new information, In the 1960s and 1970s, during our nomics have resolved the problems. The especially about peak oil. formative years in graduate school, warning in The Limits to Growth—and our curricula and our thoughts were even the more general notion of limits to Early Warning Shots growth—are seen as invalid. A discussion of the resource/popula- Even ecologists have largely shifted tion issue always starts with Thomas Charles A. S. Hall is a professor at the College of their attention away from resources to Malthus and his 1798 publication First Environmental Science and Forestry of the State focus, certainly not inappropriately, on Essay on Population: University of New York at Syracuse. John W. various threats to the biosphere and Day is a professor emeritus in the Department of biodiversity. They rarely mention the I think I may fairly make two pos- Oceanography and Coastal Sciences of Louisiana basic resource/human numbers equa- tulata. First, that food is necessary State University. Both are systems ecologists with wide-ranging interests and experience in energy tion that was the focal point for earlier to the existence of man. Secondly, and resource management. Address for Hall: Col- ecologists. For example, the February that the passion between the sexes lege of Environmental Science and Forestry, State 2005 issue of the journal Frontiers in is necessary, and will remain near- University of New York, Syracuse, NY 13210. Ecology and the Environment was dedi- ly in its present state…. Assuming Internet: [email protected] cated to “Visions for an ecologically sus- then, my postulata as granted, I

230 American Scientist, Volume 97 Ladi Kirn/Alamy Figure 1. The global population has doubled in the last four decades, as exemplified in this crowded market in India. Although some regions suffer from poverty, the world has avoided widespread famine mostly through the increased use of fossil fuels, which allows for greater food production. But what happens when we run out of cheap oil? Predictions made in the 1970s have been largely ignored because there have not been any serious fuel shortages up to this point. However, a reexamination of the models from 35 years ago finds that they are largely on track in their projections.

say, that the power of popula- affluence—albeit only recently. Paul The first 20th-century scientists to tion is indefinitely greater than Roberts, in The End of Food, reports that raise again Malthus’s concern about the power in the earth to produce malnutrition was common through- population and resources were the subsistence for man. Population, out the 19th century. It was only in ecologists Garrett Hardin and Paul Eh- when unchecked, increases in a the 20th century that cheap fossil en- rlich. Hardin’s essays in the 1960s on geometrical ratio. Subsistence ergy allowed agricultural productivity the impacts of overpopulation includ- increases only in an arithmetical sufficient to avert famine. This argu- ed the famous Tragedy of the Commons, ratio. A slight acquaintance with ment has been made many times be- in which he discusses how individu- numbers will shew the immensity fore—that our exponential escalation als tend to overuse common property of the first power in comparison in energy use, including that used in to their own benefit even while it is of the second. agriculture, is the principal reason that disadvantageous to all involved. Har- we have generated a food supply that din wrote other essays on population, Most people, including ourselves, grows geometrically as the human pop- coining such phrases as “freedom to agree that Malthus’s premise has not ulation has continued to do likewise. breed brings ruin to all” and “nobody held between 1800 and the present, as Thus since Malthus’s time we have ever dies of overpopulation,” the latter the human population has expanded avoided wholesale famine for most of meaning that crowding is rarely a di- by about seven times, with concom- the Earth’s people because fossil fuel rect source of death, but rather results mitant surges in nutrition and general use also expanded geometrically. in disease or starvation, which then kill www.americanscientist.org 2009 May–June 231 of fossil fuels. Other ecologists, includ- ing George Woodwell and Kenneth Watt, discussed people’s negative im- pact on ecosystems. Kenneth Bould- ing, Herman Daly and a few other economists begin to question the very foundations of economics, including its dissociation from the biosphere nec- essary to support it and, especially, its focus on growth and infinite substitut- ability—the idea that something will always come along to replace a scarce resource. These writers were part and parcel of our graduate education in ecology in the late 1960s. Meanwhile Jay Forrester, the inven- tor of a successful type of computer random-access memory (RAM), began to develop a series of interdisciplinary analyses and thought processes, which AP Images AP he called system dynamics. In the books Figure 2. A village on one of Bangladesh’s coastal islands was devastated by a cyclone in 1991, and papers he wrote about these mod- in which a total of more than 125,000 people were killed. Large storms had caused destruction in 1970, and would again in 2006. Although people in areas such as these are aware of the risk, els, he put forth the idea of the coming overcrowding often prevents them from moving to safer regions. difficulties posed by continuing human population growth in a finite world. The people. This phrase came up in an es- food supplies, human health and na- latter soon became known as the limits- say reflecting on the thousands of peo- ture, and that Malthusian processes to-growth model (or the “Club of Rome” ple in coastal Bangladesh who were (war, famine, pestilence and death) model, after the organization that com- drowned in a typhoon. Hardin argued would sooner rather than later bring missioned the publication). The mod- that these people knew full well that human populations “under control” els were refined and presented to the this region would be inundated every down to the carrying capacity of the world by Forrester’s students Donella few decades but stayed there anyway world. Meanwhile agronomist David Meadows and Dennis Meadows and because they had no other place to live Pimentel, ecologist Howard Odum and their colleagues. They showed that expo- in that very crowded country. This pat- environmental scientist John Steinhart nential population growth and resource tern recurred in 1991 and 2006. quantified the energy dependence of use, combined with the finite nature of Ecologist Paul Ehrlich argued in The modern agriculture and showed that resources and pollution assimilation, Population Bomb that continued popu- technological development is almost would lead to a serious decline in the lation growth would wreak havoc on always associated with increased use material quality of life and even in the numbers of human beings. At the same time, geologist M. King Hubbert predicted in 1956 and again in 1968 that oil production from the coterminous United States would peak in 1970. Although his predictions were dismissed at the time, U.S. oil produc- tion in fact peaked in 1970 and natural gas in 1973. These various perspectives on the limits to growth seemed to be fulfilled in 1973 when, during the first energy crisis, the price of oil increased from $3.50 to more than $12 a barrel. Gaso- line increased from less than $0.30 to $0.65 per gallon in a few weeks while available supplies declined, because of a temporary gap of only about 5 percent between supply and projected demand. Americans became subject for the first time to gasoline lines, large Bettman/Corbis increases in the prices of other energy Figure 3. In 1979 motorists were forced to line up for rationed gasoline during a period of oil- sources, and double-digit inflation price shocks and reduced production. Such events were compelling support for the argument with a simultaneous contraction in that the world’s population could be limited by a finite amount of natural resources. total economic activity. Such simulta-

232 American Scientist, Volume 97 neous inflation and economic stagna- tion was something that economists had thought impossible, as the two were supposed to be inversely related. Home heating oil, electricity, food and coal also became much more expen- sive. Then it happened again: Oil in- creased to $35 a barrel and gasoline to $1.60 per gallon in 1979. Some of the economic ills of 1974, such as the highest rates of unemploy- ment since the Great Depression, high interest rates and rising prices, re- turned in the early 1980s. Meanwhile, new scientific reports came out about AP Images/Brennan Linsley all sorts of environmental problems: acid rain, global warming, pollution, loss of biodiversity and the depletion of the Earth’s protective ozone layer. The oil shortages, the gasoline lines and even some electricity shortages in the 1970s and early 1980s all seemed to give credibility to the point of view Figure 4. In drought-stricken southeast Ethiopia, displaced people wait for the official distri- that our population and our economy bution of donated water. Children who try to make off with the resource hours ahead of the had in many ways exceeded the abil- appointed time are chased off by a man with a cane. Such incidents demonstrate that water is another resource often available only in limited quantities. ity of the Earth to support them. For many, it seemed like the world was falling apart, and for those familiar ity more generally, arising from nature’s QBSBNFUFS QSFEJDUFE BDUVBM with the limits to growth, it seemed as constraints. They felt that their view if the model’s predictions were begin- was validated by this turn of events QPQVMBUJPO 
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MFWFMT vironmental management, including possible prices. This would also cause food supply, river management and, all productive forces to be optimally SFTPVSDFT  especially, obtaining energy itself. A deployed, at least in theory. DPQQFS  main focus of our papers was energy re- Economists particularly disliked the turn on investment (EROI) for obtaining perspective of the absolute scarcity of PJM  oil and gas within the United States, resources, and they wrote a series of TPJM  which declined substantially from the scathing reports directed at the scien- GJTI  1930s to the 1970s. It soon became ob- tists mentioned above, especially those vious that the EROI for most of the most closely associated with the lim- QPMMVUJPO  possible alternatives was even lower. its to growth. Nuclear fusion was cit- Declining EROI meant that more and ed as a contender for the next source $0  more energy output would have to be of abundant, cheap energy. They also OJUSPHFO  devoted simply to getting the energy found no evidence for scarcity, saying QFS
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Most seemed to show that, when corrected a time period are difficult to obtain; many mainstream economists, and a lot of for inflation, the prices of all basic re- pollutants such as sewage probably have in- other people too, did not like the con- sources (except for forest products) had creased more than the numbers suggest. On cept that there might be limits to eco- not increased over nine decades. Thus, the other hand, pollutants such as sulfur have nomic growth, or indeed human activ- although there was little argument that largely been controlled in many countries. www.americanscientist.org 2009 May–June 233 cratic collective tastes of all people were reflected in their economic choices. For those few scientists who still cared about resource-scarcity issues, there was not any specific place to apply for grants at the National Science Foundation or even the Department of Energy (except for studies to improve energy efficien- cy), so most of our best energy analysts worked on these issues on the week- end, after retirement or pro bono. With very few exceptions graduate training in energy analysis or limits to growth withered. The concept of limits did live on in various environmental issues such as disappearing rain forests and coral reefs, and global climate change. But these were normally treated as their own specific problems, rather than as a more general issue about the relationship be- Christian Science Monitor/Getty Images Monitor/Getty Science Christian tween population and resources. Figure 6. Oil is not the only resource that may have peaked, with use outstripping the Earth’s ability to support the level of consumption. In Sardinia, off the coast of Italy, commercial A Closer Look fishermen’s catches are down by 80 percent compared to what their fathers used to haul in. For a distinct minority of scientists, there was never any doubt that the the higher-quality resources were be- bet and had to pay Simon $576. The in- economists’ debate victory was illusory ing depleted, it seemed that technical cident was widely reported through im- at best, and generally based on incom- innovations and resource substitutions, portant media outlets, including a dis- plete information. For example, Cutler driven by market incentives, had and paraging article in the New York Times J. Cleveland, an environmental scien- would continue indefinitely to solve Sunday Magazine. Those who advocated tist at Boston University, reanalyzed the longer-term issues. It was as if the for resource constraints were essentially the Barnett and Morse study in 1991 market could increase the quantity of discredited and even humiliated. and found that the only reason that the physical resources in the Earth. So indeed it looked to many as though prices of commodities had not been The new behavior of the general the economy had responded with the increasing—even while their highest economy seemed to support their view. invisible hand of market forces through quality stocks were being depleted— By the mid-1980s the price of gasoline price signals and substitutions. The was that for the time period analyzed had dropped substantially. The enor- economists felt vindicated, and the re- in the original study, the real price of mous new Prudhoe Bay field in Alaska source pessimists beat a retreat, although energy had been declining because of came online and helped mitigate to some effects of the economic stagnation the exponentially increasing use of oil, some degree the decrease in produc- of the 1970s lasted in most of the world gas and coal, whose real prices were si- tion of oil elsewhere in the U.S., even until about 1990. (They live on still in multaneously declining. Hence, even as as an increasing proportion of the oil places such as Costa Rica as unpaid debt more and more energy was needed to used in America was imported. Energy from that period.) By the early 1990s, win each unit of resources, the price of as a topic faded from the media and the world and U.S. economies basically the resources did not increase because from the conversations of most people. had gone back to the pre-1973 model the price of energy was declining. Unregulated markets were supposed to of growing by at least 2 or 3 percent a Likewise, when the oil shock induced lead to efficiency, and a decline in en- year with relatively low rates of infla- a recession in the early 1980s, and Eh- ergy used per unit of economic output tion. Inflation-corrected gasoline prices, rlich and Simon made their bet, the re- in Japan and the U.S. seemed to provide the most important barometer of energy laxed demand for all resources led to evidence for that theory. We also shifted scarcity for most people, stabilized and lower prices and even some increase in the production of electricity away from even decreased substantially in response the quality of the resources mined, as oil to coal, natural gas and uranium. to an influx of foreign oil. Discussions of only the highest-grade mines were kept In 1980 one of biology’s most per- scarcity simply disappeared. open. But in recent years energy prices sistent and eloquent spokesmen for The concept of the market as the ul- increased again, demand for materials resource issues, Paul Ehrlich, was timate objective decider of value and in Asia soared and the prices of most “trapped,” in his words, into making a the optimal means of generating vir- minerals increased dramatically. Had bet about the future price of five miner- tually all decisions gained more and Ehrlich made his bet with Simon over als by economist Julian Simon, a strong more credibility, partly in response to the past decade, he would have made a advocate of the power of human inge- arguments about the subjectivity of de- small fortune, as the price of most raw nuity and the market, and a disbeliever cisions made by experts or legislative materials, including the ones they bet in any limits to growth. The price of all bodies. Decisions were increasingly on, had increased by 2 to 10 times in re- five went down over the next 10 years, turned over to economic cost-benefit sponse to huge demand from China and so Ehrlich (and two colleagues) lost the analysis where supposedly the demo- declining resource grades.

234 American Scientist, Volume 97 Another problem is that the eco- nomic definition of efficiency has not SF TP been consistent. Several researchers, VS DF including the authors, have found T that energy use—a factor that had C not been used in economists’ produc- JSUIT tion equations—is far more important than capital, labor or technology in explaining the increase in industrial production of the U.S., Japan and EF Germany. Recent analysis by Vaclav B B UI JU Q T Q P Smil found that over the past decade B Q V
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 nology, however, is a two-edged sword,        whose benefits can be substantially ZFBS blunted by Jevons’s paradox, the concept that increases in efficiency often lead to Figure 9. The rate at which oil is discovered globally has been dropping for decades (blue), and is lower prices and hence to greater con- projected to drop off even more precipitously in future years (green). The rate of worldwide con- sumption of resources. sumption, however, is still continuing to rise (red line). Thus, the gap between supply and demand And technology does not work for of oil can be expected to widen. Data courtesy of the Association for the Study of Oil and Gas. free. As originally pointed out in the early 1970s by Odum and Pimentel,  increased agricultural yield is achieved principally through the greater use of fossil fuel for cultivation, fertilizers, pesticides, drying and so on, so that it takes some 10 calories of petroleum to  DPBM
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236 American Scientist, Volume 97 Europe has on average some 30 to 60 public discussion, in part because of change, in any meaningful way, we or more “energy slaves,” machines to an inaccurate understanding of both need to make them again central to ed- “hew their wood and haul their water,” what those earlier papers said and the ucation at all levels of our universities, whose power output is equal to that of validity of many of their predictions. and to debate and even stand up to many strong people. Most environmental science textbooks those who negate their importance, for Thus a key issue for the future is focus far more on the adverse impacts we have few great intellectual leaders the degree to which fossil and other of fossil fuels than on the implications on these issues today. We must teach fuels will continue to be abundant and of our overwhelming economic and economics from a biophysical as well cheap. Together oil and natural gas even nutritional dependence on them. as a social perspective. Only then do supply nearly two-thirds of the energy The failure today to bring the potential we have any chance of understanding used in the world, and coal another reality and implications of peak oil, or solving these problems. 20 percent. We do not live in an infor- indeed of peak everything, into scien- mation age, or a post-industrial age, tific discourse and teaching is a grave Bibliography or (yet) a solar age, but a petroleum threat to industrial society. Barnett, H., and C. Morse. 1963. Scarcity and age. Unfortunately, that will soon end: The concept of the possibility of a Growth: the Economics of Natural Resource It appears that oil and gas production huge, multifaceted failure of some sub- Availability. Baltimore: Johns Hopkins Uni- versity Press. has reached, or soon will reach, a maxi- stantial part of industrial civilization is Campbell, C., and J. Laherrere. 1998. The end of mum. We reached that point for oil in so completely outside the understanding cheap oil. Scientific American March: 78–83. the U.S. in 1970 and have also now of our leaders that we are almost totally Cleveland, C. J. 1991. Natural resource scarcity reached it in at least 18, and probably unprepared for it. For large environmen- and economic growth revisited: Economic the majority, of the 50 most significant tal and health issues, from smoking to and biophysical perspectives. In Ecological oil-producing nations. The important flooding in New Orleans, evidence of Economics: The Science and Management of Sustainability. Edited by R. Costanza. New remaining questions about peak oil are negative impacts has historically preced- York: Columbia University Press. not about its existence, but rather, when ed general public acceptance and policy Day, J., et al. 2007. Restoration of the Mississip- it occurred for the world as a whole, actions by several decades. pi Delta: Lessons from Hurricanes Katrina what the shape of the peak will be and There are virtually no extant forms and Rita. Science 315:1679–1684. how steep the slope of the curve will be of transportation, beyond shoe leath- Ehrlich, P. R., and J. P. Holdren. 1971. Impact of as we go down the other side. er and bicycles, that are not based on population growth. Science 171:1212–17. The other big question about oil is oil, and even our shoes are now often Forrester, J. W. 1971. World Dynamics. Cam- not how much is left in the ground (the made of oil. Food production is very bridge: Wright-Allen Press. answer is a lot) but how much can be energy intensive, clothes and furniture Hall, C. 2004. The myth of sustainable devel- opment: Personal reflections on energy, extracted at a significant energy profit. and most pharmaceuticals are made its relation to neoclassical economics, and The EROI of U.S. petroleum declined from and with petroleum, and most Stanley Jevons. Journal of Energy Resources from roughly 100:1 in 1930, to 40:1 jobs would cease to exist without pe- Technology 126:86–89. in 1970, to about 14:1 in 2000. Even troleum. But on our university cam- Hall, C. A. S., and C. J. Cleveland. 1981. Petro- these figures are relatively positive puses one would be hard pressed to leum drilling and production in the United States: Yield per effort and net energy anal- compared to EROI for finding brand- have any sense of that beyond com- ysis. Science 211:576–79. new oil in the U.S., which, based on plaints about the increasing price of Hall, C. A. S., et al. 2001. The need to reinte- the limited information available, ap- gasoline, even though a situation simi- grate the natural sciences with economics. pears likely to approach 1:1 within a lar to the 1970s gas shortages seemed BioScience 51:663–673. few decades. to be unfolding in the summer and Hubbert, M. K. 1969. Energy resources. In the Historically most of the oil supplies fall of 2008 in response to three years National Academy of Sciences–National Re- in the world were found by exploring of flat oil production, assuaged only search Council, Committee on Resources and Man: A Study and Recommendations. San new regions for oil. Very large reser- when the financial collapse decreased Francisco: W. H. Freeman. voirs were found rather quickly, and demand for oil. Meadows, D., D. Meadows and J. Randers. most of the world’s oil was found by No substitutes for oil have been 2004. Limits to Growth: The 30-Year Update. about 1980. According to geologist developed on anything like the scale White River, Vt.: Chelsea Green Publishers. and peak-oil advocate Colin Camp- required, and most are very poor net Odum, H. T. 1973. Environment, Power and Soci- bell, “The whole world has now been energy performers. Despite consider- ety. New York: Wiley Interscience. seismically searched and picked over. able potential, renewable sources (other Smil, V. 2007. Light behind the fall: Japan’s electricity consumption, the environment, Geological knowledge has improved than hydropower or traditional wood) and economic growth. Japan Focus, April 2. enormously in the past 30 years and it currently provide less than 1 percent Tierney, J. 1990. Betting the planet. New York is almost inconceivable now that major of the energy used in both the U.S. and Times Magazine December 2: 79–81. fields remain to be found.” the world, and the annual increase in the use of most fossil fuels is generally Energy Scarcity much greater than the total production The world today faces enormous (let alone increase) in electricity from For relevant Web links, consult this problems related to population and wind turbines and photovoltaics. Our ­issue of American Scientist Online: resources. These ideas were discussed new sources of “green” energy are sim- intelligently and, for the most part, ac- ply increasing along with (rather than http://www.americanscientist.org/ curately in many papers from the mid- displacing) all of the traditional ones. issues/id.78/past.aspx dle of the last century, but then they If we are to resolve these issues, in- largely disappeared from scientific and cluding the important one of climate www.americanscientist.org 2009 May–June 237