THREE
In 1979, President Jimmy Carter was presented with the findings of an ad hoc committee convened by the National Academy of Sciences to investigate whether human activities might change climate in harmful ways. The group was led by Jule Charney, a pioneering atmospheric scientist at the Massachusetts Institute of Technology, and the committee included some of the most distinguished researchers of the day. The Charney Report predicted that a doubling of CO2 in the atmosphere would lead to a rise in global temperatures of about 3 degrees Celsius. As of today, this prediction is right on schedule. The report also predicted that the world would see noticeable changes in climate by the end of the millennium. This was a radical prediction for its day, but it turned out to be vastly too conservative; noticeable changes would begin in the next decade.
It’s important to note how courageous the report’s predictions were given the state of climate science in the late 1970s. At that time, the conventional wisdom was that climate changed at a stately pace, measuring in the thousands of years. Scientists had numerous proxies to reconstruct recent and regional climate changes through tree rings and lake and seabed sediments, but as they tried to probe further back in time, the resolution of the proxies became more blurry and the proxies themselves more ambiguous. At this point, few scientists were even looking for signs of rapid climate change. Some visionary oceanographers and geophysicists argued that past climate epochs had seen very rapid changes, but in 1979, that view was an outlier. Yet here was a distinguished panel arguing that climate might change rapidly, and in just a few years. But nobody was listening.
The lack of proxies, the lack of theory about how climate might change rapidly, and an indifferent public were just a few obstacles facing climate scientists. There were very few research stations gathering data about the vast stretches of permafrost in the Far North. Researchers knew that the frozen ground trapped truly enormous amounts of greenhouse gases such as carbon dioxide and methane, but conventional wisdom was that this icy layer, which had been stable throughout modern history, would continue to be so. In any event, at the predawn of the climate change era, if warming came to the permafrost, scientists would have a hard time noticing it.
The polar regions had been much more actively studied than the permafrost, and in 1980, Antarctica’s vulnerable ice shelves had been in place for hundreds if not thousands of years, and the great ice sheets looked immutable. If anything, conventional wisdom tilted toward ice sheet thickening in the coming years.
The Charney Report never addressed whether sea levels might rise. The varied impacts of climate change were beyond the group’s mandate. The members had major hurdles to overcome simply to convince politicians and policymakers that humans might actually alter temperatures. A discussion of impacts could come later. At that point, sea level had been close to stable for thousands of years.
Nor were scientists noticing much change in the midlatitude and tropical glaciers of the world. Equatorial glaciers are particularly hard to maintain given the intense solar radiation they endure. Still, perhaps the most iconic home of a tropical glacier, Mount Kilimanjaro, seemed stable in 1980. It had more than a dozen glaciers then, and its ice cover dated back more than eleven thousand years.
Kilimanjaro is unique. A massive three-coned volcano that erupts from the African plain, it is the tallest freestanding mountain on the planet. Its ice fields had begun shrinking before 1980, but this was because of a shift in precipitation patterns in the late nineteenth century. Precipitation is crucial for equatorial glaciers. Not only does it replace ice lost to the impacts of direct sunlight, but a snow layer lying on top of a glacier also protects the underlying ice by reflecting the sun’s rays.
In 1980, researchers knew that a number of glaciers were retreating, but the widely shared assumption was that this was due to regular climate cycles; researchers trying to predict future conditions did not expect a major glacial retreat. This meant that in those early days of trying to imagine how greenhouse gas emissions might impact lives, there was not much concern that glaciers would be a major thing to consider.
Perhaps the most important factor influencing scientific conventional wisdom in the late 1970s was that temperatures had begun to rise only a few years earlier, after more than thirty years of remaining relatively cool. That temporary cooling had to do with a number of factors, including the massive amounts of particulates thrown into the air by coal burning and other emissions in the years before clean-air regulations and other pollution controls.
The cooling preceding the 1970s produced some mixed messages. The attention to particulates and questions about where the planet stood in terms of orbital dynamics related to ice ages led a few scientists to speculate that the earth might enter a period of cooling rather than warming. In 1975, the National Academy of Sciences issued a report that mentioned this possibility but also argued that the weight of evidence favored warming.
The idea that the future held global cooling was never more than a fringe concept. A study of seventy-one peer-reviewed papers during that period by the American Meteorological Society revealed that forty-four came down on the side of warming, twenty were neutral, and seven predicted the possibility of cooling.
Despite this, the mainstream media made it seem as though a scientific consensus had solidified around the cooling hypothesis, most notably in a 1975 Newsweek science story. This was never the case, and by the late 1970s, the cooling hypothesis had faded completely. Scientists were now clear that if humans had the power to change the chemical balance of the atmosphere through greenhouse gas emissions, the result would be warming. By 1976, the late Stephen Schneider, the most prominent scientist associated with the cooling hypothesis, had firmly thrown in his lot with the warming camp.
While the global cooling dustup came and went rather quickly, a more persistent line of dissent came from scientists who argued that any warming resulting from greenhouse gases would be offset by changes in cloud cover as the earth warmed. Clouds do have a big impact on surface temperatures, and their response to increased CO2 proved very difficult to model. Some clouds have a cooling effect by reflecting sunlight and providing shade, while others warm the surface by acting like a blanket. Richard Lindzen, an MIT professor, put forward a theory that warming tropical oceans would thin cirrus cover in the tropics, allowing heat to escape and thereby keep global temperatures in balance. Lindzen still promotes this so-called iris hypothesis, which has made him wildly popular with climate denialists.fn1
The Charney Report was a major milestone noting the threat of global warming, but it was not the first time that potential human-caused climate change received presidential attention. In 1965, President Lyndon Johnson spoke of humans running “a geophysical experiment” with the atmosphere. Prior to the Charney recommendations, a Global 2000 report commissioned by Jimmy Carter in 1977 also referenced the problem. George Woodwell, the founder of the Woods Hole Research Center (recently renamed the Woodwell Climate Research Center), tried to get the threat of CO2 on international conference agendas as far back as 1970. He told me that he failed because other scientists controlling the agendas insisted that there was no evidence greenhouse gases were having any effect.
While scientists and policymakers struggled to get a grip on the issue of greenhouse warming in the 1960s and 1970s, an invaluable scientific advance on climate change came out of the most prosaic and unexciting type of science: monitoring. Though it may seem like drudgework, monitoring has been foundational, providing hard data to mobilize action on many environmental issues. Had British scientist Joseph Farman not seen anomalous readings about ozone in the upper atmosphere over Antarctica, it might have been years after 1982 that scientists discovered the ozone hole, and the delay might have been disastrous.
With regard to greenhouse gases, the decision to collect a long-term record of CO2 in the atmosphere grew out of a distinguished oceanographer’s desire to confirm a theory about CO2 uptake by the oceans—a problem that had nothing to do with global warming. After studying the intricate chemical reactions by which oceans absorb carbon dioxide, Roger Revelle theorized that after certain thresholds were reached in the upper layers of the oceans, additional carbon dioxide would be expelled back into the atmosphere by evaporation. To confirm his hypothesis, he needed to see whether changes in the atmosphere matched his projections. It was his luck to find Charles Keeling, a Caltech postdoc student who was obsessive about such monitoring.
Gathering data, first from Antarctica and then from the top of the volcano Mauna Loa in Hawaii, Keeling began monitoring the atmosphere in 1956. The baseline for preindustrial levels of atmospheric CO2 had been established at 280 parts per million. As early as 1958, Keeling’s measurement showed levels had increased to 315 parts per million. And since then, readings from Mauna Loa have been on an unrelenting ascent, increasing to the present 420 ppm.
At many points during his long career, Keeling’s funding was threatened by the deep-seated prejudice in big science that monitoring was not real science. Keeling relied on grants from the National Academy of Sciences, and George Woodwell remembers that on more than one occasion they initially denied Keeling’s proposals, saying that he needed to do experiments, not “just” monitoring. Woodwell and others would intercede, saying that the work was vital, and Keeling would keep his funding.
Despite his pioneering work on the interactions of the oceans and atmosphere with regard to CO2, Revelle regarded the threat of global warming more as a curiosity and matter of academic interest for much of his career. This proved to be fodder for denialists. In 1982, Revelle wrote a letter to Scientific American arguing that as of that time there was still no clear signal of warming that could be separated from natural variation, though he expected that such a signal might appear in the next ten to fifteen years. It came sooner than that.fn2
To be clear, no reputable scientist had issue with the basic theory of the greenhouse effect. All recognized that heat-trapping gases impacted surface temperatures. The question, in 1979, was by how much human-produced emissions would impact climate, and when those changes would occur.
One source of confusion, trumpeted by those who opposed taking action on climate change, was that even though CO2 was increasing in the atmosphere, the amounts were tiny. Finding a concentration of 315 parts per million is like finding 1 red marble in a bowl filled with 3,149 white marbles. Doubling that amount would mean that there were 2 such marbles in an overwhelming sea of white. Could that possibly matter?
It turns out it does. The relationship of CO2 levels and global temperatures was settled long before global warming became an issue. That didn’t stop deniers from raising this dissent well into the 1990s. In his book A Moment on the Earth, published in 1995, Gregg Easterbrook ridiculed global warming on precisely these grounds.
I chose the Charney Report as the start of the modern climate change era because it marked an inflection point in science. It contained this prophetic sentence: “A wait-and-see policy may mean waiting until it is too late.” In terms of action, the world did adopt a wait-and-see policy, and we may have waited until it was too late. In the years following, rising global temperatures set off alarms, which, in turn, greatly accelerated the pace of scientific discovery.
To sum up the state of play in 1979, scientists and concerned policymakers had to deal with a distracted public and no noticeable changes in the biggest and most ominous potential impacts of a changing climate—temperatures, glaciers, the permafrost, sea level—that might have been used to get the public’s attention. Other impediments to raising public concern were relatively low-resolution proxies for studying how quickly climate had changed in the past and a conventional scientific wisdom that assumed that any such changes would be far off in the future.
The authors of the Charney Report were not alone in arguing that the change might come sooner, even by the year 2000. And, at least during the Carter administration, these scientists were getting a hearing in the White House. In a memo prepared for President Carter at the urging of Gus Speth, then head of the Council on Environmental Quality (CEQ), Woodwell, with backing from science adviser Frank Press, wrote that greenhouse gas emissions would produce “a warming that will probably be conspicuous within the next twenty years.” They were right, but no one was listening.
A major problem for those few scientists who recognized that climate changes might come soon was that they needed a scientific basis for any prediction of such a rapid response. A small group of scientists, notably the late oceanographer Wallace Broecker, were trying to figure out what mechanism could bring about a rapid change. Inspiring that search were teasing glimpses that climate had changed rapidly in the past. Broecker began making that argument during his days as a graduate student in the 1950s. In 1973, he published an article in Science entitled “Climatic Change: Are We on the Brink of a Pronounced Global Warming?,” introducing a phrase that would come to describe climate change for the public going forward.fn3
Broecker and others who took the view that climate change was coming and that it might be rapid were marginalized in the 1970s. Broecker was known as an aggressive personality with a big ego, and this may have limited his influence at that point. “It’s easy to make enemies in science,” remarks Woodwell. Moreover, Broecker and others had only ambiguous evidence that such rapid changes had occurred in the past and, at that time, lacked a convincing theory of what might bring it about.
And yet some scientists were nonetheless willing to go on record saying that changes might be manifest in a matter of decades. Gus Speth says that such an outcome came directly from the models upon which the Carter administration’s last report on the climate threat, issued in January 1981, was based. At that point, no one expected the incoming Reagan administration to act on its recommendations.
In any event, according to Speth, the overwhelming opinion of the scientists in the government was that the issue was real but that we had a lot of time to deal with it. Speth says that even Frank Press thought there were more urgent issues to address. “In the White House, there’s always something more urgent,” Speth remarked.
Even if scientific opinion had coalesced around the threat of climate change to the point where it might have galvanized public opinion, most alternatives to fossil fuels were inefficient, cumbersome, and costly. In 1977, solar cells cost about $77 per kilowatt-hour. Today, the same cell costs $0.06 per kilowatt-hour, and utility-scale solar projects generate power at $0.046 per kilowatt-hour, according to the Department of Energy. Those concerned about climate change in the 1970s were well aware that there were no cost-effective alternatives to fossil fuels. A 1977 memo to Jimmy Carter obtained by Spencer Weart of the American Institute of Physics contains just such a warning. Frank Press, the geophysicist who was Carter’s science adviser, noted that “the urgency of the problem derives from our inability to shift rapidly to non-fossil-fuel sources once the climatic effects become evident not long after the year 2000; the situation could grow out of control before alternate energy sources and other remedial actions become effective.”
Press was prescient, though climatic effects became evident long before 2000. We can only imagine what might have happened had Carter not lost to Reagan and the momentum of the Carter administration continued to bring down the cost of renewables. Speth, for one, is convinced that had Carter been reelected, he would have continued to push research on solar and that the day renewables achieved grid parity—the holy grail of renewables where solar, wind, and other sources compete head-to-head with fossil fuels on costs—would have come much sooner than it has.
Indeed, one thing the Carter years demonstrated was that investment in renewables could dramatically increase their efficiency. Just before Carter took office, a watt of solar power cost about seventy-seven dollars. By the time he left office in 1981, that cost had come down to less than twenty-five dollars a watt. Since then, costs have decreased by about 10 percent a year. Today, an installed watt (solar cell plus installation) costs less than seventy cents, and in some parts of the world utility-scale solar power costs less than half the price of the cheapest coal-produced electricity.
Moreover, today, almost all the new jobs in the energy sector are in renewables. They’ve proven their economic case. It would have made a world of difference had this happened sooner. This is one tragedy of the dawn of the climate change era.
Climate science structurally lags reality, but scientists did have some indicators of change that could be monitored. Among the most noticeable were readings of CO2 concentrations: Keeling’s findings showed that they were climbing significantly above preindustrial levels. Other indications of change would have been hard to tease from the noise as the climate had only just begun to change in 1979.fn4 But the structural lags in science would become a greater issue in the 1980s and beyond simply because just after the turn of the decade, climate changes began coming thick and fast.