Rex Tillerson, CEO of ExxonMobil, at the World Gas Conference, Paris, June 2015

Pascal Sittler/REA/Redux

Rex Tillerson, CEO of ExxonMobil, at the World Gas Conference, Paris, June 2015

Earlier this year our organization, the Rockefeller Family Fund (RFF), announced that it would divest its holdings in fossil fuel companies. We mean to do this gradually, but in a public statement we singled out ExxonMobil for immediate divestment because of its “morally reprehensible conduct.”1 For over a quarter-century the company tried to deceive policymakers and the public about the realities of climate change, protecting its profits at the cost of immense damage to life on this planet.

Our criticism carries a certain historical irony. John D. Rockefeller founded Standard Oil, and ExxonMobil is Standard Oil’s largest direct descendant. In a sense we were turning against the company where most of the Rockefeller family’s wealth was created. (Other members of the Rockefeller family have been trying to get ExxonMobil to change its behavior for over a decade.) Approached by some reporters for comment, an ExxonMobil spokesman replied, “It’s not surprising that they’re divesting from the company since they’re already funding a conspiracy against us.”2

What we had funded was an investigative journalism project. With help from other public charities and foundations, including the Rockefeller Brothers Fund (RBF), we paid for a team of independent reporters from Columbia University’s Graduate School of Journalism to try to determine what Exxon and other US oil companies had really known about climate science, and when. Such an investigation seemed promising because Exxon, in particular, has been a leader of the movement to deny the facts of climate change.3 Often working indirectly through front groups, it sponsored many of the scientists and think tanks that have sought to obfuscate the scientific consensus about the changing climate, and it participated in those efforts through its paid advertisements and the statements of its executives.

It seemed to us, however, that for business reasons, a company as sophisticated and successful as Exxon would have needed to know the difference between its own propaganda and scientific reality. If it turned out that Exxon and other oil companies had recognized the validity of climate science even while they were funding the climate denial movement, that would, we thought, help the public understand how artificially manufactured and disingenuous the “debate” over climate change has always been. In turn, we hoped this understanding would build support for strong policies addressing the crisis of global warming.

Indeed, the Columbia reporters learned that Exxon had understood and accepted the validity of climate science long before embarking on its denial campaign, and in the fall of 2015 they published their discoveries in The Los Angeles Times.4 Around the same time, another team of reporters from the website InsideClimate News began publishing the results of similar research.5 (The RFF has made grants to InsideClimate News, and the RBF has been one of its most significant funders, but we didn’t know they were engaged in this project.) The reporting by these two different groups was complementary, each confirming and adding to the other’s findings.

Following publication of these articles, New York Attorney General Eric Schneiderman began investigating whether ExxonMobil had committed fraud by failing to disclose many of the business risks of climate change to its shareholders despite evidence that it understood those risks internally. Massachusetts Attorney General Maura Healey soon followed Schneiderman with her own investigation, as did the AGs of California and the Virgin Islands, and thirteen more state AGs announced that they were considering investigations.

Bernie Sanders and Hillary Clinton each called for a federal investigation of ExxonMobil by the Department of Justice. Secretary of State John Kerry compared Exxon’s deceptions to the tobacco industry’s long denial of the danger of smoking, predicting that, if the allegations were true, Exxon might eventually have to pay billions of dollars in damages “in what I would imagine would be one of the largest class-action lawsuits in history.”6 Most recently, in August, the Securities and Exchange Commission began investigating the way ExxonMobil values its assets, given the world’s growing commitment to reducing carbon emissions. An article in The Wall Street Journal observed that this “could have far-reaching consequences for the oil and gas industry.”7

We didn’t expect ExxonMobil to admit that it had been at fault. It is one of the largest companies in the world—indeed, if its revenues are compared to the gross domestic products of nations, it has one of the world’s larger economies, bigger than Austria’s, for example, or Thailand’s8—and it has a reputation for unusual determination in promoting its self-interest.9 One way or another, we expected it to fight back—most likely, we thought, by proxy, through its surrogates in the right-wing press and in Congress.

Sure enough, various bloggers have been calling for “the Rockefellers”10 to be prosecuted by the government for “conspiracy” against Exxon under the Racketeer Influenced and Corrupt Organizations (RICO) Act.11 (Such lines of attack are being tested and refined, and we expect they will soon be repeated in journals with broader readership.) And in May, Texas Republican Lamar Smith, the chair of the House Committee on Science, Space, and Technology, sent a letter to the RFF and seven other NGOs (including the RBF,, Greenpeace, and the Union of Concerned Scientists),12 as well as all seventeen AGs who said they might investigate ExxonMobil. He accused us of engaging in “a coordinated effort to deprive companies, nonprofit organizations, and scientists of their First Amendment rights and ability to fund and conduct scientific research free from intimidation and threats of prosecution,” and demanded that we turn over to him all private correspondence between any of the recipients of his letter relating to any potential climate change investigation. When we all refused, twice, to surrender any such correspondence, Smith subpoenaed Schneiderman, Healey, and all eight NGOs for the same documents.


We will answer Smith’s accusations against us presently. In order to explain ourselves, however, we first have to explain what Exxon knew about climate change, and when—and what, despite that knowledge, Exxon did: the morally reprehensible conduct that prompted our actions in the first place.

Large oil companies must possess considerable scientific expertise. In that respect as in others, Exxon has always been an industry leader: the company today says it employs about 16,000 scientists and engineers.13 And the basic mechanism of climate change is relatively straightforward, long-established science. In the 1850s, John Tyndall discovered that atmospheric carbon dioxide acts as a “greenhouse gas,” meaning that it reflects heat rising from the earth back to the planet’s surface. The Swedish geochemist Svante Arrhenius realized at the beginning of the twentieth century that people were burning fossil fuels in quantities great enough to warm the entire planet with the CO2 they released. In 1965, Lyndon Johnson told Congress, “This generation has altered the composition of the atmosphere on a global scale through…a steady increase in carbon dioxide from the burning of fossil fuels.”14 So it is no surprise that by the late 1970s and early 1980s, Exxon scientists largely understood climate change—not only its basic mechanism but many of its implications, including its potential implications for the oil business—and had explained it to the company’s leaders.

In 1977, for example, an Exxon scientist named James Black gave a presentation to the company’s Management Committee. He explained, accurately, what the “greenhouse effect” is and how measurements of atmospheric CO2 that had been taken since 1957 showed it was steadily increasing. And, although emphasizing that climate science still had to deal with untested assumptions and uncertainties, he said that “current opinion overwhelmingly favors attributing atmospheric CO2 increase to fossil fuel combustion.”15 “Present thinking,” Black added a year later, “holds that man has a time window of five to ten years before the need for hard decisions regarding changes in energy strategies might become critical.”16

By 1980, a report written by Exxon’s Canadian subsidiary and distributed to Exxon managers around the world stated matter-of-factly, “It is assumed that the major contributors of CO2 are the burning of fossil fuels…and oxidation of carbon stored in trees and soil humus…. There is no doubt that increases in fossil fuel usage and decreases in forest cover are aggravating the potential problem of increased CO2 in the atmosphere.”17 The next year Roger Cohen, director of Exxon’s Theoretical and Mathematical Sciences Laboratory, wrote in an internal memo that by 2030, projected cumulative carbon emissions could, after a delay, “produce effects which will indeed be catastrophic (at least for a substantial fraction of the earth’s population).”18

In 1982, Cohen added that “over the past several years a clear scientific consensus has emerged”: atmospheric CO2 would double from its preindustrial quantity sometime in the second half of the twenty-first century, producing an average increase in global temperature of three degrees Celsius, plus or minus 1.5 degrees. “There is unanimous agreement in the scientific community,” he went on, “that a temperature increase of this magnitude would bring about significant changes in the earth’s climate, including rainfall distribution and alterations in the biosphere.”19

It was clear, too, what a problem these conclusions posed for the oil industry. As a 1979 Exxon memo reported,

Models predict that the present trend of fossil fuel use will lead to dramatic climatic changes within the next 75 years…. Should it be deemed necessary to maintain atmospheric CO2 levels to prevent significant climatic changes, dramatic changes in patterns of energy use would be required.20

In other words, the world would have to curtail its use of fossil fuels substantially. Senior Exxon scientist Henry Shaw warned management that according to the predictions of the National Academy of Sciences, global warming, not any lack of supply, would force humankind to stop burning fossil fuels.21


In 1982, an Exxon environmental affairs manager named Marvin Glaser wrote a thirty-nine-page primer on climate change that he distributed widely among management.22 It confirmed that, despite remaining points of scientific uncertainty, “mitigation of the ‘greenhouse effect’ would require major reductions in fossil fuel combustion.” If these weren’t achieved, Glaser warned, “all biological systems are likely to be affected” and “there are some potentially catastrophic events that must be considered,” including an expected “dramatic impact on soil moisture, and in turn, on agriculture,” and, eventually, the melting of the Antarctic ice sheet, which would flood “much of the US East Coast, including the State of Florida and Washington D.C.” He believed that “potentially serious climate problems are not likely to occur until the late 21st century,” but added, “once the effects are measurable, they might not be reversible.”

Climate scientist James Hansen at a mock gravestone declaring ‘Climate Change: A Matter of Life and Death,’ Coventry, England, March 2009

Darren Staples/Reuters

Climate scientist James Hansen at a mock gravestone declaring ‘Climate Change: A Matter of Life and Death,’ Coventry, England, March 2009

If much was already understood about climate change, however, there were still points of uncertainty. Scientists knew that the ocean, for example, would absorb some fraction of the CO2 being added to the atmosphere (and become more acidic in the process), but just how much was unclear. They also knew that the ocean acted as a thermal reservoir—that it would absorb a great deal of the additional heat reflected back to the planet’s surface from increased atmospheric CO2, beginning to release it only after a considerable delay, perhaps of decades. But just how long that delay would be depended on how much mixing there was between the ocean’s upper and lower depths, and that wasn’t well understood either.

Cohen’s “clear scientific consensus” notwithstanding, such lingering questions meant that scientists still disagreed about precisely how much the climate would change, and how quickly. The computerized models they were building to forecast those effects were also considered much more reliable in predicting average global changes than specific regional ones (except near the poles, where almost everyone agreed that warming would be particularly severe). None of these legitimate uncertainties in climate science, however, implied any doubt about its main conclusions: that the changing climate would soon have dramatic impacts on the earth, and that it was primarily caused by humans burning fossil fuels.23

Many Exxon scientists and executives wanted to be able to predict how severe climate change would be and when, to better anticipate changes in energy policy. They wanted not only to understand the science thoroughly, but to earn a reputation as trusted leaders in it so they could better defend the company’s interests against “conclusions drawn from the [international research] program which might be biased for political or other reasons.”24 As Henry Shaw put it, “We should determine how Exxon can best participate in [climate research] and influence possible legislation on environmental controls. It is important to begin to anticipate the strong intervention of environmental groups and be prepared to respond with reliable and credible data.”25

So, with its extraordinary resources, Exxon became a corporate leader in climate science. It equipped its largest supertanker as a research vessel, measuring CO2 concentrations in the atmosphere and at different depths of the ocean all along the ship’s route.26 It also became expert in computerized climate modeling, not only to evaluate the predictions of others but to help improve such models. Ultimately, one of its scientists published nearly fifty peer-reviewed papers about various technical aspects of climate change.27

The company’s early findings may not have been quite what management was looking for, however. In 1985, for example, Exxon astrophysicist Brian Flannery and NYU physicist Martin Hoffert wrote a chapter for a US Department of Energy report using their own climate models to predict global warming of as much as six degrees Celsius by the end of the twenty-first century unless greenhouse gas emissions were reduced.28 As Roger Cohen had written three years earlier, “The results of our research are in accord with the scientific consensus on the effect of increased atmospheric CO2 on climate.” Cohen believed that “our ethical responsibility is to permit the publication of our research in the scientific literature; indeed to do otherwise would be a breach of Exxon’s public position and ethical credo on honesty and integrity.”29

Then, however, in 1988, the United States was struck by the costliest drought in its history. Widespread heat waves were blamed for more than five thousand deaths; fires swept over the West, engulfing much of Yellowstone National Park. That June, the NASA scientist James Hansen told Congress that “the greenhouse effect is real, it is coming soon, and it will have major effects on all peoples.”30 Suddenly the notion of global warming was everywhere—Time named “Endangered Earth” its “Planet of the Year.” And Exxon’s public position changed dramatically.

In August 1988, an Exxon public affairs manager drafted a memo called “The Greenhouse Effect.” He acknowledged that “the principal greenhouse gases are by-products of fossil fuel combustion.” However, he wrote, the “Exxon Position” would now be to “emphasize the uncertainty in scientific conclusions regarding the potential enhanced greenhouse effect.”31

What did that mean? In 1989 Duane LeVine, Exxon’s manager of science and strategy development, told the company’s board of directors that the scientific consensus was now that global temperatures would rise by 1.5 to 4.5 degrees Celsius by the middle of the twenty-first century, with “enormous potential global impacts.” But, he added, “arguments that we can’t tolerate delay and must act now can lead to irreversible and costly Draconian steps.” So Exxon would “extend the science,” convincing policymakers and the public that climate change was still insufficiently understood and that more research needed to be done before significant action could be warranted. Meanwhile, it would emphasize the cost of reducing carbon emissions.32

This strategy recalled to us the conclusions of the book Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming, in which the historians of science Naomi Oreskes (Harvard) and Erik Conway (California Institute of Technology) tell the story of what they call the “Tobacco Strategy.” Tobacco industry scientists and executives knew by 1953 that smoking caused cancer. Rather than see sales diminish, however, they decided to deceive the public. Since the proof of smoking’s danger was established by science, they resolved on a long-term effort to create doubt about that science. And they realized that the best, most credible messengers in a campaign to discredit established science would be other scientists.33

The tobacco industry found and funded scientists who, “cherry-picking data and focusing on unexplained or anomalous details,” would argue that the causal link between smoking and cancer had not been proven. (Since there are lingering uncertainties around any settled point of science—why some smokers get lung cancer and others don’t, for example—this is always an easy argument to make, even when it is a specious one.) By this time, the scientific consensus was that smoking’s danger had been proven; those who denied it were dramatically outnumbered. But the industry also funded a network of “free-market,” antiregulatory think tanks to repeat and amplify the claims of its scientists. (It tried to hide the fact that it was paying these scientists and think tanks, often routing its payments through front groups like law firms or right-wing foundations.)

Then the industry manufactured an artificial “‘debate,’ convincing the mass media that responsible journalists had an obligation to present ‘both sides’ of it.” The industry didn’t need to win this debate, its leaders realized; only to keep it going. “Doubt is our product,” explained a tobacco executive’s 1969 memo, “since it is the best means of competing with the ‘body of fact’ that exists in the minds of the general public. It is also the means of establishing a controversy.”34

As we know, this campaign ultimately failed, but it succeeded for an astonishingly long time. The tobacco industry didn’t begin losing court cases until the 1990s, some four decades after realizing that its product killed its customers.35 In the meantime, it made enormous profits. Other industrial leaders took note, and when they found themselves in similar situations—when scientists had shown that their businesses were causing acid rain, depleting the ozone layer, or harming human health, and when, in consequence, they faced the prospect of governmental regulation—they began copying the tobacco strategy. In doing so they often relied on the same small group of scientists and think tanks that the tobacco industry had used.36

When Exxon began to “emphasize the uncertainty” of climate science, the scientists who espoused its positions were often veterans of those earlier denial campaigns. Among them were Fred Seitz, Fred Singer, Robert Jastrow, and Bill Nierenberg. They had all been reputable, prominent physicists during the cold war, but they eventually became, essentially, professional deniers of science, arguing on one issue after another that findings harmful to industry were “unproven,” “junk science.” Oreskes and Conway believe that their motivation was less mercenary than ideological, although they were often paid by the organizations they directed or worked with, which in turn were supported by the industries they defended. They were all fervent anti-Communists and ardent free-market purists. Especially after the cold war ended, they saw environmentalists as the next great threat to capitalism, since, by pointing out the damage industry sometimes does to the environment and human health, defenders of the environment are implicitly criticizing the workings of free markets and bolstering the case for regulation.37

These men were not experts in climate science, and the reports they wrote, though adorned with “the trappings of scientific argumentation—graphs, charts, references, and the like,” were not “subject to independent peer review—the most basic requirement of any truly scientific work.”38 It seems quite clear that they sometimes consciously misrepresented real science in their arguments, persisting even after their fallacies and distortions were revealed publicly.39 Sometimes Seitz and Singer and others simply tried to smear the legitimate climate scientists whose work seemed most threatening to them.40 Either way, their claims were echoed, promoted, and “validated” by the same free-market think tanks that had previously fought the scientific consensus on issues like smoking, acid rain, and the ozone layer—think tanks that Exxon funded.41 Then the fake debate they created was broadcast further and given an additional veneer of credibility by journalists, some of whom were persuaded by spurious arguments about the need for “balanced” reporting, even on issues the scientific community considered settled, and some of whom, it turned out, were simply in Exxon’s pay.42

Exxon didn’t always rely on the writings of such scientists. For decades it published frequent “advertorials” on the editorial page of The New York Times, questioning the reality of climate change or its human cause, or arguing that predictions about global warming were too unreliable to justify efforts to prevent it.43 And in 1997, for example, at the World Petroleum Congress in Beijing, Exxon CEO Lee Raymond gave a speech in which he claimed, falsely, that “the earth is cooler today than it was twenty years ago.” (1997 would be the hottest year ever measured; that record has been broken repeatedly since then.)44 Raymond went on to disparage the climate models his own scientists had helped develop, and concluded by saying:

Let’s agree there’s a lot we really don’t know about how climate will change in the twenty-first century and beyond. That means we need to understand the issue better, and fortunately, we have time. It is highly unlikely that the temperature in the middle of the next century will be significantly affected whether policies are enacted now or twenty years from now.45

In 1998 Exxon participated in a $6 million public relations campaign by the American Petroleum Institute (a trade association which Exxon heavily influenced and supported) to prevent the United States from ratifying the Kyoto Protocol, an international treaty to reduce greenhouse gas emissions. The “action plan” for this campaign stated:

Victory will be achieved when: average citizens “understand” (recognize) uncertainties in climate science; recognition of uncertainties becomes part of the “conventional wisdom”…[and] those promoting the Kyoto treaty on the basis of extant science appear to be out of touch with reality.

But, it cautioned, “unless ‘climate change’ becomes a non-issue, meaning that the Kyoto proposal is defeated and there are no further initiatives to thwart the threat of climate change, there may be no moment when we can declare victory for our efforts.”46 The campaign was highly successful: the US never did join the Kyoto Protocol.

Still, ExxonMobil (as it became in 1999) continued to spend extraordinary sums on lobbying, directly and through trade associations: $240 million since 1998.47 And in 2001, soon after President George W. Bush was inaugurated, the company’s chief lobbyist sent a memo to the White House making several requests. He asked the new administration to get rid of the scientist who chaired the Intergovernmental Panel on Climate Change (IPCC), the UN body that is the world’s leading authority on the subject. He also asked that a number of other scientists and officials be fired from their jobs in the White House and the State Department, to be replaced by known climate skeptics.48 Exxon CEO Raymond and Vice President Dick Cheney were old friends, and Cheney had already taken practical control of the administration’s energy policy.49 ExxonMobil got its wishes.50 As Treasury Secretary Paul O’Neill said around the same time to the Environmental Protection Agency administrator Christine Todd Whitman, when she told him that Cheney had convinced Bush to repudiate his campaign promises about limiting carbon emissions, “We just gave away the environment.”51

ExxonMobil and its allies are still standing in the way of effective action to address climate change, as we will show in a second article.

This is the first of two articles.