The Public and Climate Change

Already in the 1930s, many people noticed that their weather was getting warmer. Few connected this with human activity, and still fewer feared any harm. Gradually scientists, aided by science journalists, informed the minority of educated people that modern civilization might cause global warming, sometime far in the future. In the early 1970s, the question began to concern a wider public. By then most people had come to fear planet-wide harm from technology in general. Now an onslaught of droughts suggested we were already damaging the climate. The issue was confused, however, when experts debated whether pollution would bring global warming or, instead, an appalling new ice age. By the end of the 1970s, scientific opinion had settled on warming, although only in a remote and uncertain future. Some scientists nevertheless went directly to the public to demand action to avert the warming, and a few politicians took up the issue. It was during the hot summer of 1988 that outspoken scientists, convinced by new evidence that rapid climate change might be imminent, made the public fully aware of the problem. Scientific discussions now became entangled with fierce political debates over pollution and government regulation.... This essay deals mainly with the United States, but opinions were generally similar in other industrialized nations. The response of American policy-makers is covered in an essay on Government: the View from Washington.

Threats of Climate Disaster (Early 1970s)

The first Earth Day, held in 1970, marked the emergence of environmentalism into powerful political action. New public attitudes supported bitter attacks on authorities, especially in government and industry. They were the villains held responsible for pollution and many other problems. To the new breed of environmentalists, almost any novel technology looked dangerous. As one example, the press revealed that the U.S. military in Vietnam had engaged in a massive cloud-seeding program, trying to bog down the Communist army with rains. The military was now widely despised, and in the eyes of many around the world, this attempt at climate modification was malignant. Where once people had held utopian hopes for the ways humanity would modify the environment, either deliberately or as a side-effect of "progress," now such "interference" seemed ignorant, reckless, and perhaps wicked. In every democratic industrial nation, citizens pressed their government to enact environmental protection laws. Governments gave way, taking steps to reduce smog, clean up water supplies, and the like. Meanwhile bureaucracies improved the organization (and in some cases the funding) of research on the atmosphere, along with every other element of the environment.

The new attitudes affected scientists along with everyone else. Some experts were getting worried about climate change, and made deliberate efforts to stir up other scientists and the public. Especially important was a "Study of Critical Environmental Problems" organized in 1970 at the Massachusetts Institute of Technology. The organizer was Carroll Wilson, a dynamic science policy entrepreneur who had earlier managed the U.S. Atomic Energy Commission. Under his expert leadership, some 40 scientists deliberated for a month over desertification, pollution of the air and oceans, and other harms. In their concluding conference report, as the first item in a big list of potential problems, the scientists pointed to the global rise of CO₂. The risk of global warming, they declared, was "so serious that much more must be learned about future trends of climate change." ⁽¹⁾ The media paid some attention, although they mostly overlooked global warming among more immediate pollution threats.

Wilson followed up the MIT study by organizing a meeting of experts in Stockholm. This "Study of Man's Impact on Climate," focused tightly on climate change, was a landmark in the development of awareness. The group concluded with a ringing call for attention to the dangers of humanity's emissions of greenhouse gases and particle pollutants. Their widely read report gave as its epigraph a Sanskrit prayer: "Oh, Mother Earth... pardon me for trampling on you." ⁽²⁾ Another example of the new tone was a deliberately provocative 1971 book titled Impingement of Man on the Oceans. "The shocking reality," said the author, "is that the hour is fast approaching when the people of the Earth will have exhausted nature's ability to adjust to the complexities of human attack." ⁽³⁾

Contemplating the relationship between science and society, some people would say that the judgment of scientists bent under the pressure of the mass prejudices of the day. Others would say that public opinion responded intelligently to new scientific facts. Both views go too far in separating scientific from popular thought. In regions like North America and Europe, where the public was relatively well educated and informed, the views of scientists and public tended to evolve together.

Not everyone adopted such thinking. Many still felt, as the veteran meteorologist Joseph Smagorinsky had declared in 1969, that "our physical environment must be considered an enemy to humanity until we master it." ⁽⁴⁾ But the rhetoric and attitudes of the environmental movement spread rapidly, not only among the general public but also among climate researchers. Smagorinsky himself worried in 1972 that we were standing "at the threshold of a possible crisis which could have as much of an impact on man as his invention of war." ⁽⁵⁾

Climate was now seen as one of the planet's vulnerable spots, and many people expected that whatever we did to it would be for the worse. For example, in 1969 (Feb. 20) the New York Times reported that greenhouse warming of the Arctic Ocean might make the pole ice-free within a decade or two. The resulting climate change would turn much of the United States and Europe from breadbaskets to deserts. On the other hand, the Times article continued, some scientists held there was a cooling trend. That too could be blamed on humanity. Increased dust and other aerosols, stirred up by agriculture and industry, might bring destructive cold spells.

Science reporters were especially impressed by a 1972 warning from the oceanographer Cesare Emiliani. His ground-breaking research on past climate cycles had persuaded him that in the natural course of events the present "amiable climate" should give way, within the next few thousand years, to a new ice age. But the prediction, Emiliani explained, might be confounded by human interference such as deforestation and pollution, for the climate was extremely unstable. "We may soon be confronted with a runaway glaciation," Time magazine quoted him as saying--or perhaps instead a "runaway deglaciation" that would flood our coastal cities. ⁽⁶⁾ The most common scientific viewpoint was summed up by a scientist who explained that the rise in dust pollution worked in the opposite direction from the rise in CO₂, so nobody could say whether there would be cooling or warming. In any case, "We are entering an era when man's effects on his climate will become dominant." ⁽⁷⁾

Climate pronouncements like this were no longer always hidden in the back pages. In the early 1970s, the public learned that climate change could be an urgent problem. What aroused them was a spectacular series of disasters. In 1972, drought ravaged crops in the Soviet Union and several other regions; this caught attention around the world when the Soviet government made massive grain purchases and prices rose sharply. Also in 1972 the Peruvian fisheries collapsed because of an El Niño event, while the Indian monsoon failed (and again in 1974). Meanwhile droughts struck the Midwestern United States too, severely enough to show up repeatedly on the front pages of newspapers and in television news programs. Most dramatic of all, years of drought struck the African Sahel and reached an appalling peak in 1972, threatening millions with starvation, bringing on mass migrations and hundreds of thousands of actual deaths. Television and magazine pictures of sun-scorched fields and emaciated refugees brought home just what climate change could signify.

Climate scientists did not know what caused any of this, but some publicly suggested that humans were partly responsible. Looking at the disaster in Africa in particular, they speculated that our pollution of the atmosphere was changing global weather patterns. Or perhaps overgrazing of the semi-arid Sahel had started a vicious cycle, where the barren ground reflected more sunlight, altering the winds so as to cause further desertification. Whatever the cause of the disasters, they undercut the public's traditional belief that weather conditions would never get far from their old accustomed pattern. Climate scientists had already been moving away from that during the past decade. People increasingly understood that there existed no such a thing as a "normal" climate, and many began to worry that permanent shifts were underway. ⁽⁸⁾

The rise in attention can be seen in the popular articles in U.S. magazines listed in the Readers' Guide to Periodical Literature under the rubric "Global temperature change." The articles put interviews of climate scientists alongside the recurring news of droughts and other weather disasters. In the mid 1970s, the number exploded from roughly three articles per year to more than twenty. ⁽⁹⁾ That was still a low level compared with many other issues that agitated the public. But it was enough so that well-read people would be generally aware of climate change as a public issue.

This was not brought about by any deliberate public relations campaign. Nearly all scientists felt their job was to pursue research and publish it in technical journals. Anything important would presumably come to the attention of science journalists and policy-makers. For really important problems, the scientists could convene a study group (like the "Study of Man's Impact on Climate" held in Stockholm in 1971) and issue a report. Experts like Revelle were more than willing to explain their ideas when asked, and they might even make an effort to come up with quotable phrases for reporters. On request they would give a talk on the state of climate science or write it up for a magazine like Scientific American, which reached, not exactly the public, but the part of the public that was well educated and interested in science. This mild part-time activity was fairly effective, for science journalists did notice and amplify anything that could make a good story.

As usual, news media drew attention to the worst dangers. Various journalists reported that scientists suspected the weather fluctuations could be the harbinger of another ice age. To be sure, most articles made it clear that the top scientists frankly admitted uncertainty. Many scientists believed that cooling was no more likely than global warming, or than no particular change at all. Newsweek explained, in a direct quote from a National Academy of Sciences report, that "Not only are the basic scientific questions largely unanswered, but in many cases we do not yet know enough to pose the key questions." Yet there was one thing that nearly all experts agreed on, news reports explained. As Time put it, "the world's prolonged streak of exceptionally good climate has probably come to an end--meaning that mankind will find it harder to grow food." ⁽¹⁰⁾ When rising population crashed against the increasingly erratic weather, the world might face widespread famine, even warfare over the dwindling food supply.

Perhaps this was not just bad luck. "We have broken into the places where natural energy is stored and stolen it for our own greedy desires," a journalist declaimed. "Our tampering with the delicate balances of nature can cause major dislocations... and many people intuitively and logically conclude that some great natural law is about to catch up with us.... A few see in such catastrophes the just hand of divine judgment and retribution against materialist sinners..." ⁽¹¹⁾

A leader in stirring public anxiety was the respected climate expert Reid Bryson. Scarcely any popular article on climate in the 1970s lacked a Bryson quote or at least a mention of his ideas. His big worry was the increase in smoke and dust, not only from industry but also from lands laid waste by deforestation and slash-and-burn agriculture. Already in the late 1960s, he had gone to the public to warn that such pollution was probably bringing on global cooling. ⁽¹²⁾ He explained that like the smoke from a huge volcanic eruption, the "human volcano" could cause disastrous shifts in weather patterns. His claims were forcefully stated and unequivocal, backed up by an argument that the droughts in Africa and India already showed how air pollution was halting the rain-bringing monsoons. Journalists quoted Bryson's warnings that the effects of human interference "are already showing up in rather drastic ways" (as Fortune magazine reported in 1974). We faced unprecedented dangers, he said, perhaps "a billion people starving." ⁽¹³⁾

Most climate experts thought Bryson went too far, yet the majority of them did worry. Thus a 1974 study by leading figures, convened by the National Academy of Sciences, concluded that "there is a finite probability that a serious worldwide cooling could befall the Earth within the next 100 years." The shift, moreover, could be "rather sudden." ⁽¹⁴⁾ Another official (or official-sounding) endorsement came in 1976 with the publication of a secret 1974 report by the Central Intelligence Agency. The CIA gave dire warnings that impending cooling could bring economic dislocation and perhaps even wars. "There would be increasingly desperate attempts on the part of powerful but hungry nations to get grain any way they could. Massive migrations, sometimes backed by force, would become a live issue..." The CIA report, based chiefly on Bryson's theory, was publicly attacked by other climate scientists as "sloppy" and full of "patent nonsense" (Bryson himself had to spend a good part of the next year explaining to people that he wasn't responsible for what it said). However, news accounts went on to say that nearly all scientists did admit that severe climate variations were possible. ⁽¹⁵⁾

News of these reports and studies was still relegated to a few paragraphs on the inside pages of the better newspapers or in the science-and-culture section of news magazines, reaching only the more alert citizens. This limited but important audience, if they happened to open to the right page on the right day, might notice a significant discovery. Strong new evidence showed that the coming and going of ice ages followed a rhythm set by predictable astronomical fluctuations of the Earth's orbit around the Sun. Projecting these fluctuations forward, several experts concluded that we were now in the descending part of the natural cycle, with the onset of the next ice age scheduled to come within a few thousand years.

The technical details were condensed in occasional popular articles. The respected oceanographer James Hays, for example, told the elite Saturday Review audience that within centuries "it may very well get cold enough to allow great glaciers thousands of feet thick to cover North America as far south as Long Island." Noting that other scientists predicted that greenhouse warming could cancel out this natural climate trend, Hays warned that more pollution, by blocking sunlight, "could tip the balance" and launch us into an ice age. ⁽¹⁶⁾ Members of the public who wanted to read more about all this could find a book-length popularization of the ideas of Bryson and like-minded scientists in The Cooling. The journalist author warned that "we could possibly witness the beginning of the next Great Ice Age. Conceivably,... we would see mass global famine in our lifetimes, perhaps even within a decade." ⁽¹⁷⁾

Meanwhile Bryson's group found evidence that climate could change severely in the course of only a few decades. Journalists promptly reported this to the public, and trotted out the old theory of Ewing and Donn about the sudden onset of an ice age (not overlooking the tale of mammoths found buried in permafrost with grass in their stomachs). Some scientists "even believe the glaciers could return within our lifetime," exclaimed a science writer in the Saturday Evening Post. Bryson remarked indignantly, "I am probably the most misquoted climatologist in the United States." ⁽¹⁸⁾

In truth, scientific opinion was shifting toward the idea that small perturbations could trigger sudden climate change. Abstract theoretical studies were showing how a complex system of feedbacks like climate could even lurch all on its own, unpredictably. The Saturday Evening Post article correctly cited studies from lake sediments and ice cores that hinted that severe cold could descend in as little as a century. ⁽¹⁹⁾ A slower global warming seemed more likely to many experts. A few scientists, however, suggested that if global warming was underway it might release a mountainous surge of ice from Antarctica. By cooling down the oceans that could bring an ice age, perhaps within decades.

The ideas seemed plausible to Nigel Calder, a respected British science journalist, who featured them in a two-hour television feature about weather that was broadcast in 1974. One short but memorable segment warned of a possible "snowblitz" set off by an Antarctic ice surge, or directly by global warming or pollution, or just by pure chance. Entire countries could be obliterated under layers of snow, said Calder, and billions would starve. The new ice age "could in principle start next summer, or at any rate during the next hundred years." This was the first time the threat of abrupt climate change appeared as the subject of a major television presentation. ⁽²⁰⁾ But it was an isolated case, and it did not reach beyond the minority who watched educational shows on public television. Climate change was not yet a topic of widespread public discussion.

Atmospheric Scientists and Industrial Policies (Latter 1970s)

A few scientists thought the prospects of a calamity were so serious that they must make a personal effort to address the public directly. Bryson wrote a book titled Climates of Hunger, published in 1977. Drawing on his group's historical researches, he described how native American societies had been destroyed by the sudden onset of prolonged droughts, far worse than anything known in recent centuries. A better-documented historical case, noted by many writers, was the "Little Ice Age" that had chilled the North Atlantic region from the 15th through the 18th century. Starvation had loomed as crops failed in the dank summers, the Thames at London and the Baltic Sea had frozen solid in winter, while advancing glaciers had crushed entire villages in the Alps and Viking colonies in Greenland had collapsed. ⁽²¹⁾ Bryson warned that such disasters could hit our own civilization unpredictably and swiftly. ⁽²²⁾

Another climatologist who worked hard to warn of a possible climate calamity was the young Stephen Schneider. He and his journalist wife wrote a popularizing book, the Genesis Strategy: Climate and Global Survival. Insisting that climate could change more quickly and drastically than most people imagined, they advised the world to devise policies to cushion the shocks, such as building a more robust agricultural system. As Joseph had advised Pharaoh in the Book of Genesis, we should prepare for lean years to follow fat ones. ⁽²³⁾

A few experts stirred public interest with ideas of still more drastic action: enormous global engineering projects to deliberately bend the climate to our will. Most scientists dismissed the ideas, but not because they sounded like science fiction. It seemed only too plausible that humanity could alter the climate. However, our knowledge was so primitive that any intervention might only make things worse.

Some scientists criticized Bryson, Schneider, and others who spoke directly to the public. The time spent writing a book and going about the country delivering public lectures was time away from doing "real" science. Worse, most scientists felt that any definite statement about climate change was premature. The whole subject was so riddled with uncertainties that it seemed unfit for presentation to the scientifically naive public. Experts whose profession demanded accuracy were upset by the shortcuts some colleagues took when explaining things in lay language. They particularly disliked the blunt and colorful statements, necessarily imprecise, that were necessary to catch the public's ear. Since debate over the likelihood of severe climate change had become a salient public issue, any statement might be dragged into the media arena. Reporters were quizzing experts at scientific meetings and telephoning them with urgent questions about one or another discovery that was about to be published. Climate science professionals, accustomed to life in a quiet academic backwater, found the change both gratifying and disturbing.

Many of the experts felt that the climate controversy was inflated by a few irresponsible scientists and sensation-seeking journalists, agitating for no good reason. As the Director-General of the United Kingdom Meteorological Office explained in a 1976 lecture, the official message was, "no need for panic induced by the prophets of doom." With other meteorologists, perhaps the majority, he insisted that "the climatic system is so robust, and contains so much inherent stability through the presence of negative feedback mechanisms, that man has still a long way to go before his influence becomes great enough to cause serious disruption...." ⁽²⁴⁾ In fact the public showed no signs of panic nor even much anxiety. The traditional belief in the benign "balance of nature" was still widely held. Warnings of a future climate calamity sounded no different from the countless other future threats that newspapers had been trumpeting for a hundred years.

We don't know the public's response for sure, since nobody took a poll. But a largely indifferent attitude is suggested by the very lack of polling, or any other distinct reaction by the experts who kept their finger on the public pulse. Politicians, even better attuned to public feelings, did show some desultory reactions. A few bills dealing with climate were proposed in the U.S. Congress, and the administration undertook a mild reorganization of climate research. But most politicians showed little interest in the topic.

Yet climate change was becoming a political issue, if only in the narrow sense that policies were at stake. At professional meteorological conferences, debates over technical questions such as the rate of CO₂ buildup became entangled with debates over how governments should respond. In some meetings scientists addressed the policy issues formally in papers and working groups, struggling with questions far beyond their professional expertise. How much should reliance on fossil fuels be reduced, if at all? Should the destruction of tropical forests be a main target for reform? How much money and effort should be spent on averting climate change, amid the struggle to feed the world's poor? With demands for equity rising and centralized government threatening freedom, what policies were desirable? Or even politically feasible? Which was more dangerous--to exclaim about the worst possible harms, and give science a reputation for sensationalism, or to offer cautious scenarios, which might delay action until it was too late? Was it even proper for a scientist to speak, as a scientist, on social questions? ⁽²⁵⁾

The different approaches showed up in exchanges like the following, at a 1972 symposium where scientists argued over intractable calculations on how much CO₂ was emitted during deforestation. "I guess I am rather conservative...," one expert remarked. "I really would like to see a better integration of knowledge and better data before I would personally be willing to play a role in saying something political about this." A colleague replied, "To do nothing when the situation is changing very rapidly is not a conservative thing to do." ⁽²⁶⁾

Unable to agree even whether the world was likely to get warmer or colder, the scientists did unanimously agree that the first step must be to redouble the effort to understand how the climate system worked. Calls for research always came naturally to researchers, but from the early 1970s onward, climate scientists issued these calls with increased frequency and passion. Even in technical articles in professional journals, many authors now went out of their way to state that an increased research effort was urgently needed. Interviewed by journalists, most climate scientists said they required far more data and analysis. In other words, governments should put up more money. As one meteorologist put it, "public opinion is being alerted and thus politicians may be able to act." ⁽²⁷⁾

Not only more funds, but better organization seemed necessary. Individual scientists were backed up by official committee reports pressing these issues. In particular, around 1974 U.S. scientists made a concerted effort, both in public and behind the scenes among officials, to urge their government to found a National Climate Program. That would give them both unified direction and sharply increased funding. Gathering data and organizing research on climate change, one expert explained, "should be regarded as an important aspect of national defense, or, more accurately, of defense of the entire planet against a common threat." ⁽²⁸⁾ Scientists also pushed for heightened international efforts. In the absence of a truly global public opinion, this action tended to be mostly hidden within conferences and in the corridors of bureaucracies.

A few people began to look beyond the corridors of research policy and publicly demanded immediate changes on a broader scale. Environmental activists were already attacking overgrazing, smog emissions, and so forth because of the damage in their neighborhoods. Such bad practices might alter the climate as well. But this only added one more item to the list of arguments against specific practices. During the 1970s, only a few people speculated that it might be wise to impose serious changes on industry and agriculture for the special purpose of reducing their impact on climate. That was a world away from practical politics, rarely suggested even as an abstract future goal.

An example of the auxiliary part played by climate worries came up during a controversy that gathered around itself much of the political attention that could be spared for the atmosphere. This was a public debate that began in 1970 over the U.S. government's plans to subsidize a fleet of supersonic commercial airplanes. The transports would inject large amounts of water vapor and chemical aerosol particles into the stratosphere, and some scientists warned that this could have damaging effects on global climate. The public's main worries, however, were that the fleet would be intolerably noisy, damage the high ozone layer that protected them from skin cancer, and waste taxpayers' money. Under pressure from the entire list of objections, in 1971 Congress cancelled the project, perhaps the first time in American history such a major technological initiative was defeated by public pressure invoking environmental arguments. ⁽²⁹⁾

Pursuing the new concern for the stratosphere, in 1974 two scientists noticed that certain obscure gases produced by industry (nicknamed "CFCs") lingered in the atmosphere. Some would drift up to the stratosphere where, the scientists discovered, ultraviolet rays would activate them in a process that destroyed ozone. The high, thin layer of ozone blocks the Sun's ultraviolet rays, so removing this layer would cause an increase of skin cancers, and perhaps bring still worse dangers to people, plants, and animals.

CFCs were the propellents in aerosol sprays: every day millions of people were adding to the global harm as they used cans of deodorant or paint. Science journalists alerted the public, and environmentalists jumped on the issue. Chemical industry groups fought back with public relations campaigns that indignantly denied there was any risk whatsoever. Unconvinced, citizens bombarded government representatives with letters and boycotted spray cans. A survey showed that nearly three-quarters of Americans had heard about the issue. In 1977, the U.S. Congress added restrictions on the spray can chemicals to the new Clean Air Act. ⁽³⁰⁾

Climate change was nowhere to be seen in the spray can controversy. But the threat to the ozone layer sent a stinging message about how fragile the atmosphere was, how easily human activity might damage it. And how unexpectedly. Except for the chance circumstances that had stimulated studies of high-altitude airplanes, the danger from spray can propellants might have gone unnoticed for quite a few more years.

The ozone story added to the shapeless fears that human activity was somehow endangering the entire planetary atmosphere. The majority of citizens found it hard to distinguish among the various materials, whether airplane and automobile emissions, agricultural chemicals, or industrial pollution from either traditional smokes or bizarre new substances. Many scarcely distinguished among climate change from greenhouse warming, ozone damage from CFCs, and health threats from automobile tailpipes and power plant smokestacks. It was enough to feel that an eerie toxic smog threatened the entire planetary environment.

Scientific results continued to trickle in. None of the new studies was especially striking or definitive, but there was a significant overall tendency. It seemed that climate could indeed be more delicately balanced, more subject to swift changes, than scientists had supposed. An example of the claims that briefly caught the public eye were studies that suggested that severe droughts in western America followed a cycle, driven by changes in the number of sunspots. It was a reminder that the climate might be sensitive to all sorts of small and unexpected influences. That was driven home to scientists by new data on ancient climates, observations of disturbingly large annual shifts in the amount of snow cover in the Arctic, and novel theoretical models that showed how such changes might make the climate system flip abruptly from one state to another. This idea of runaway climate became terribly vivid to both scientists and the public when space probes brought news of a hellish furnace atmosphere on Venus and a permanent ice age on Mars.

Meanwhile new studies convinced an increasing number of scientists that, given a choice between warming and cooling, it was the greenhouse effect that would dominate sooner or later. Theoretical work on aerosols suggested that human smog and dust might not cool the atmosphere very much after all. At most, the increased pollution might bring a mild cooling that would only temporarily mask greenhouse warming. Other studies suggested that the greenhouse effect might already be changing the weather. Computer models, although still provisional, tended to agree that the rising level of CO₂ would bring a degree or so of warming within decades. Any statement that invoked supercomputers commanded strong respect from the public, and from most scientists too.

Climate experts were quick to explain the new findings. A well-respected geochemist, Wallace Broecker, took the lead in 1975, warning in an influential Science magazine article that the world might be poised on the brink of a serious rise of temperature. "Complacency may not be warranted," he said. "We may be in for a climatic surprise." ⁽³¹⁾ In 1977, the National Academy of Sciences weighed in with a major study by a panel of experts who warned that temperatures might rise to nearly catastrophic levels during the next century or two. The report, announced at a press conference during the hottest July the nation had experienced since the 1930s, was widely noted in the press. ⁽³²⁾

Science journalists, by now closely attuned to the views of climate scientists, promptly reflected the shift of opinion. Media talk of a ruinous new ice age continued through the winter of 1976-1977, which was savagely cold in the Eastern half of the U.S. But that was the end of it, despite blizzards the following winter. In early 1978 the New York Times reported that a poll of climate scientists found them evenly divided on whether there would be warming, cooling, or no particular change. Nevertheless, from then on nearly all articles on climate in the Times were oriented toward greenhouse warming. In the Readers' Guide listing of U.S. popular articles, warnings about climate were more or less evenly divided between heating and cooling up to 1977, but then articles about global warming took over almost completely. ⁽³³⁾

For example, in 1976 the U.S. News & World Report described (with strong qualifications) the theories that the world would be getting cooler. The very next year the same magazine reported that "The world may be inching into a prolonged warming trend that is the direct result of burning more and more fossil fuels..." The ice-age theories, said the article, "are being convincingly opposed by growing evidence of human impact." ⁽³⁴⁾ Similarly, in 1976 Business Week had explained both sides of the debate but reported that "the dominant school maintains that the world is becoming cooler." Just one year later, the magazine declared that CO₂ "may be the world's biggest environmental problem, threatening to raise the world's temperature" with horrendous long-term consequences. ⁽³⁵⁾ No single scientific revelation lay behind this shift. Rather, several research results published in the mid 1970s (perhaps especially from supercomputer models) swayed the opinions of scientists. From them the change migrated, with the usual exaggeration and simplification, to science journalists.

In all this the journalists conveyed two important points to the public. One of these points would be obvious to anyone who read just the headlines and titles of the various articles: scientists remained uncertain and divided about what would really happen. The other point crept in on a deeper level. It was put explicitly in a 1977 Readers' Digest article where the author, after emphasizing the disagreement among experts about whether the planet would get too hot or too cold, stated his principal conclusion. "All scientists agree that a new factor has entered the game of climate change, a 'wild card' never there before--man himself." ⁽³⁶⁾

Not only future weather, but weighty questions of present policies were at stake. The worries about climate change became entangled in debates about fuel supplies. The "oil crises" of 1973 and 1979, when gasoline became shockingly expensive or even unobtainable, aroused a keen public interest in energy policy. Environmentalists were mobilizing public opinion to block nuclear power. But their preferred technology of solar power was a long way from being cheap enough (or even environmentally friendly enough) to fuel the nation. The remaining alternative was a rapid boost in coal burning. Experts, including a minority of environmentalists, pointed out that coal might be worse than nuclear power because of its polluting emissions, including greenhouse gases. Some officials in the government energy establishment called for intensive study of global warming, in case the threat turned out to be severe. "If the CO₂ problem looks big enough," one of them promised, "we'll make changes--and fast." ⁽³⁷⁾

These arguments only reached limited circles in government and industry, scarcely penetrating public consciousness. The sense of urgency about climate change was dwindling away. It had never been very strong, even during the droughts and famines of the early 1970s. By the end of the decade, the collapse of doom-filled claims about an imminent ice age, replaced by uncertain speculations about possible future warming, left little for the media to bite into. The widely reported debates over the speculations of a few scientists, added to confusion about whether even the observed temperatures were falling or rising, convinced many people that the science was too foggy to be worth much attention. Moreover, the basic climate concern of "food security"--the dread of famine that haunted everyone from grandmothers to policy makers--sank out of view for the first time in human history. In the 1970s, the biotechnology "green revolution" burst upon farmers. By the end of the century, world food prices would decline in real terms by some 70%. Neither famine nor anything else relating to climate change seemed immediately worrisome. The topic settled down as a mildly interesting public issue, far less urgent than many others.

What can people do about global warming, and what should we do? See my Personal Note and Links.

Related:

Government: The View from Washington, DC

The Modern Temperature Trend

Rapid Climate Change

Supplements:

Wintry Doom

Ice Sheets & Rising Seas

Reflections on the Scientific Process

1. SCEP (1970), p. 12; see also Matthews et al. (1971); Kellogg (1987), pp. 120-22.

2. Wilson and Matthews (1971), p. v.

3. Hood (1971), p. v, "provocative" p. vi.

4. Smagorinsky (1970), p. 25, from a talk at an August 1969 conference.

5. McIntyre (1972), p. 37.

6. New York Times, Jan. 27, 1972. Quote: Time (1972).

7. G.S. Benton, chair of Johns Hopkins Dept. of Earth & Planetary Sciences, to 1970 National Academy of Sciences symposium, New York Times, April 30, 1970.

8. Henderson-Sellers and Robinson (1986), pp. 10-11.

9. My counts. A sharp increase in coverage in magazines and newspapers in the mid 1970s is also reported by a qualitative survey, Harrison (1982), p. 737.

10. harbinger: Time (1974a); Academy report: Newsweek (1975); Time (1974b), p. 83.

11. Ponte (1976), pp. 234-35.

12. Bryson (1967).

13. Alexander (1974), quote p. 92.

14. GARP (1975), p. 189, from App. A (pp. 186-90) by J. Imbrie, W.S. Broecker, J.M. Mitchell, Jr., J.E. Kutzbach. New York Times, Jan. 19, 1975, p. 31.

15. Central Intelligence Agency, "Potential implications of trends in world population, food production, and climate," OPR-401, Aug. 1974, published as Appendix II to Impact Team (1977), quote p. 200. News of the report was first published in the New York Times, May 1, 1976, p. 2; scientists quoted: U.S. News & World Report (1976); Bryson, personal communication, 2002.

16. Hays (1973), quotes p. 29, 32.

17. Ponte (1976), p. xiv.

18. "I am a little touchy about this point," he added. Bryson testimony, May 26, 1976, United States Congress (94:2) (1976), p. 211.

19. Mammoths frozen "swiftly in their tracks," Impact Team (1977), p. 19; trigger ice age: Rasool and Schneider (1971), , see comment here on their paper; "within our lifetime," Wolkomir (1976), p. 50. (For lake sediments Wolkomir quotes David W. Folger, and for ice cores C. Langway, p. 78).

20. "The Weather Machine," BBC-television (a co-production with the U.S. Corporation for Public Broadcasting and WNET), first aired 20 Nov. 1974, expanded in a book: Calder (1975), quote p. 134; he based the "snowblitz" idea on Lamb and Woodroffe (1970); see also Brooks (1925), pp. 90-91.

21. Fagan (2000).

22. Bryson and Murray (1977).

23. Schneider and Mesirow. (1976), esp. chap. 3; Kellogg and Schneider (1974); Hammond (1976); Glantz (1977).

24. B.J. Mason, speaking mainly about aerosols and ozone. He admitted that greenhouse warming could become significant in 50-100 years. Gribbin (1976); Mason (1977).

25. Stumm (1977), articles by A.M. Weinberg and R. M. Rotty, pp. 225-39, by H. Brooks, pp. 241-52, report by A. Nir et al., pp. 312-22, and passim.

26. Reiners and Olson at 1972 Brookhaven Symposium in Biology, Reiners (1973), p. 327.

27. Bert Bolin in McIntyre (1972), p. 253.

28. Barrett and Landsberg (1975), p. 79.

29. Horwitch (1982), pp. 318-20.

30. Gribbin (1988); also Dotto and Schiff (1978); Roan (1989), see p. 58.

31. Broecker (1975), reported in New York Times, Aug. 14, 1975, p. 24. Influence of Broecker on a member of the President's Council of Economic Advisers is reported in New York Times, June 3, 1977, IV p. 13.

32. National Academy of Sciences (1977); reported: e.g., New York Times, July 25, 1977, p. 1, and Business Week (1977).

33. My counts based on titles (for a given article the titles are all that most of the public reads). Poll: New York Times, Feb. 18, 1978, p. 9. A compilation of cooling scare quotes includes items from 1971 and especially from 1975 to 1977 and none later, Bray (1991).

34. U.S. News & World Report (1976); U.S. News & World Report (1977).

35. Business Week (1976); Business Week (1977).

36. Matthews (1977), p. 92.

37. P.C. White of ERDA, quoted Business Week (1977). My own serious awareness of the greenhouse effect began ca.1980 when I began to study pro- and anti-nuclear power arguments; see the brief mention at Weart (1988), p. 338.