Exxon’s Climate Denial History: A Timeline

A review of Exxon's knowledge and subsequent denial of climate change.

© Rex Curry / Greenpeace

Exxon made the news in September and October of 2015 when research produced by InsideClimate News, the Los Angeles Times, and the Columbia Graduate School of Journalism revealed that Exxon had known since the 70s about the causes of climate change and the dangers climate disruption poses. The articles spurred a wave of actions against Exxon.

In November 2015, the New York state attorney general announced an investigation into Exxon for disclosure violations. Presidential candidates Hillary Clinton and Bernie Sanders called for a federal investigation into the company. And more than 350,000 Americans joined that call, petitioning the Department of Justice to investigate.

The news has changed the game on fossil fuel companies and their role in climate denial. But Exxon’s track record on climate science denial and climate double talk has been growing for some time. Check the timeline below for a rundown. Along the way, note how global atmospheric carbon levels continue to rise past 350 parts per million (ppm), the level scientists say is safe for human civilization as we know it, while Exxon’s profits (in nominal dollars) continue to rise.



Scientists working at Humble Oil (now ExxonMobil) publish a paper on the dilution of carbon dioxide in the atmosphere and ocean. The paper notes: “Although appreciable amounts of carbon dioxide have undoubtedly been added from soils by tilling of land, apparently a much greater amount has resulted from the combustion of fossil fuels”–indicating company scientists understood the link between fossil fuel use and rising CO2. (Source: Center for International Environmental Law)

1968 (Global CO2 level: 323 ppm, Exxon annual profit: $1.2 billion)

In a report produced for the American Petroleum Institute, scientists Elmer Robinson and R.C. Robbins note that, among the possible sources of rising CO2  in the atmosphere, “none seems to fit the presently observed situation as well as the fossil fuel emanation theory.” The paper warns that significant rises in CO2 could melt icecaps, increase sea levels, change fish distributions and increase plant photosynthesis. (Source: Center for International Environmental Law)


1978 (Global CO2 level: 335 ppm, Exxon annual profit: $2.4 billion)

James Black, working under Exxon’s Products Research Division, writes an internal briefing paper called “The Greenhouse Effect” following from a 1977 presentation to Exxon’s management committee. The paper warns that human-caused emissions could raise global temperatures and result in serious consequences. “Present thinking 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,” Black writes in his summary of the presentation. (Source:InsideClimate News)


At the urging of an Exxon scientist, Henry Shaw, Exxon begins analyzing the absorption rate of carbon dioxide in the oceans, considered one of the key questions of climate science at the time. “Exxon must develop a credible scientific team that can critically evaluate the information generated on the subject and be able to carry bad news, if any, to the corporation,”Shaw wrote in a letter to Exxon research executives. (Source: InsideClimate News)


Major fossil fuel companies, including Exxon, Mobil, Amoco, Phillips, Texaco, Shell, Sunoco, Sohio and Standard Oil of California and Gulf Oil (two companies that became Chevron) meet regularly as part of a task force to discuss the science and implications of climate change. The meetings are organized with the help of the American Petroleum Institute. A minutes document from one of the meetings suggests that oil companies knew that climate change was occurring, and that they would bear some responsibility for managing it. (Source: InsideClimate News)


1982  (Global CO2 level: 341 ppm, Exxon annual profit: $4.2 billion)

Exxon’s Environmental Affairs Programs manager M.B. Glaser sends Exxon management a primer on climate change. The primer is “restricted to Exxon personnel and not distributed externally.” It describes “potentially catastrophic events” if fossil fuel use is not reduced. (Source: InsideClimate News)


Roger Cohen, director of the Theoretical and Mathematical Sciences Laboratory at Exxon, writes a memo summarizing Exxon’s climate modeling research. The memo states: “The consensus is that a doubling of atmospheric CO2 from its pre-industrial revolution value would result in an average global temperature rise of (3.0 ± 1.5)°C [equal to 5.4 ± 1.7°F]…There is unanimous agreement in the scientific community 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.” Cohen would later become a lead climate science denier at an Exxon-funded front group.

1983  (Global CO2 level: 343 ppm, Exxon annual profit: $5 billion)

Exxon cuts funding for climate research from $900,000 per year to $150,000. Exxon’s total research budget at the time was more than $600 million.


An Exxon report on the Natuna gas field in Indonesia warns that the project would be “the world’s largest point source emitter of CO2 and raises concern for the possible incremental impact of Natuna on the CO2 greenhouse problem.”


The United Nations Intergovernmental Panel on Climate Change (IPCC) is formed.


Shell announces that it will redesign one of its natural gas platforms, raising it a meter or two to account for sea level rises resulting from climate change.

1989  (Global CO2 level: 353 ppm, Exxon annual profit: $3.5 billion)

Exxon and other fossil fuel companies create the Global Climate Coalition (GCC). The GCC is created to oppose mandatory reductions in carbon emissions by obscuring the scientific understanding of fossil fuels’ impact on the climate. The GCC created a scientific “backgrounder” for lawmakers and journalists that claimed “The role of greenhouse gases in climate change is not well understood.”



Dr. Brian Flannery, “representing the International Petroleum Industries’ Environmental Conservation Association, but on the payroll of Exxon,” argues strongly against wording in the IPCC’s first report, which states that global carbon emissions must be reduced 60 to 80 percent. Flannery argues that too much “scientific uncertainty” exists to recommend such reductions. IPCC scientists agree that enough certainty exists to justify the reductions, and the report moves forward. (The Carbon War by Jeremy Leggett, cited in 2002 Greenpeace report, “Denial and Deception”).

1992  (Global CO2 level: 356 ppm, Exxon annual profit: $4.8 billion)

By 1992 Exxon has become a member of American Legislative Exchange Council (ALEC), which actively undermines action on climate change at the federal and state levels. (Source: Union of Concerned Scientists)


Lee Raymond becomes CEO of Exxon.

1995 (Global CO2 level: 361 ppm, Exxon annual profit: $6.5 billion)

The Global Climate Coalition distributes an internal memo, organized by Mobil chemical engineer and climate expert Leonard Bernstein, warning that the “greenhouse effect and the potential impact of human emissions of greenhouse gases such as CO2 on climate is well established and cannot be denied.” Members of the coalition included BP, Chevron, Exxon, Mobil and Shell. (Source: Union of Concerned Scientists)


In a speech to the Economic Club of Detroit, Lee Raymond denies the scientific consensus on climate change. Raymond claims that “Currently, the scientific evidence is inconclusive as to whether human activities are having a significant effect on the global climate.”


Mobil engineers, as a part of a project jointly owned by Mobil, Shell and a subsidiary of Exxon, note that “An estimated rise in water level, due to global warming, of 0.5 meters may be assumed” in their planning for exploration and production facilities along the coast of Nova Scotia.

October 1997 (Global CO2 level: 364 ppm, Exxon annual profit: $8.5 billion)

Exxon CEO Lee Raymond tells the 15th World Petroleum Congress in Beijing that the world’s climate isn’t changing, and that even if it was, fossil fuels would play no part.

April 1998

The New York Times, with documents leaked to the National Environmental Trust, reveals that the American Petroleum Institute is organizing a $5-million plan to challenge the science of climate change. Representatives of Exxon and Chevron are listed as participating in the plan. One line item of the plan is to “Identify, recruit and train a team of five independent scientists to participate in media outreach. These will be individuals who do not have a long history of visibility and/or participation in the climate change debate. Rather, this team will consist of new faces who will add their voices to those recognized scientists who are already vocal” (p. 6 of Greenpeace report appendix).


ExxonMobil-funded think tank, the George C. Marshall Institute, co-publishes the “Oregon petition,” a petition challenging the consensus around climate change. The petition comes with a “research paper” made in the style of the Proceedings of the National Academy of Sciences, confusing some legitimate scientists into signing the petition. Other petition signatories, suspiciously, include fictional characters from the TV show M.A.S.H. and Spice Girl “Dr.” Geri Halliwell.


In its proxy statement to shareholders, Exxon reports that shareholders have requested the creation of an outside directors committee to independently review and publish “a full report about the impact on climate change on our company’s present policies and practices…[including] anticipated liabilities our company may incur from its possible contribution to the problem…” Exxon’s board recommends against the proposal, citing, among other things, that the science around climate change remains uncertain.


Exxon and Mobil merge.


2000 (Global CO2 level: 370 ppm, Exxon annual profit: $17.7 billion)

ExxonMobil publishes an ad, titled “Unsettled science,” highlighting a study showing a historical decrease in temperatures in the Sargasso Sea. CEO Lee Raymond presents the study at that year’s shareholder meeting as evidence that fossil fuels may not be causing global warming. The author of the study, Lloyd Keigwin, later complains that Exxon misused the data: “I believe ExxonMobil has been misleading in its use of the Sargasso Sea data. There’s really no way these results bear on the question of human-induced climate warming…I think the sad thing is that a company with the resources of ExxonMobil is exploiting the data for political purposes…”

January 2001

George W. Bush inaugurated as US president, with $100,000 in inaugural funding from ExxonMobil. Just days before Bush’s inauguration, Exxon’s publishes an advertisement titled “An energy policy for the new administration.” The ad argues that “the unrealistic and economically damaging Kyoto process needs to be rethought.”

February 2001

The Bush White House receives a letter from Exxon asking if the administration can oust climate scientist Robert Watson from his position as chair of the Intergovernmental Panel on Climate Change. Under Watson’s chairmanship, the IPCC had released a number of reports linking climate change to human activity.

March 2001

Bush administration announces withdrawal from the Kyoto Protocol.

May 2001

The UK Stop Esso campaign is launched. The campaign is aimed at Exxon’s subsidy Esso, and is a coalition effort that includes Greenpeace UK, People and Planet, and Friends of the Earth.

2002 (Global CO2 level: 373 ppm, Exxon annual profit: $11.5 billion)

The GCC announces it is disbanding, explaining that the group “has served its purpose by contributing to a new national approach to global warming. The Bush administration will soon announce a climate policy that is expected to rely on the development of new technologies to reduce greenhouse emissions, a concept strongly supported by the GCC.”

May 2002

Greenpeace USA launches the Stop ExxonMobil campaign. Over the following months, activist actions against Exxon stations spread around the globe.

May 2003

The Greenpeace Global Warming Crimes Unit converges on ExxonMobil’s compound in Irving, Texas, to charge the oil giant with crimes against the climate.

January 2004 (Global CO2 level: 377 ppm, Exxon annual profit: $25.3 billion)

ExxonMobil puts out a new ad titled, “Directions for climate research.” The ad argues for “uncertainties that limit our current ability to know the extent to which humans are affecting climate and to predict future changes caused by both human and natural forces.” The same month, Exxon’s “Weather and climate” ad takes a similar tack, arguing that “scientific uncertainties continue to limit our ability to make objective, quantitative determinations regarding the human role in recent climate change…”

June 2004

Greenpeace USA develops www.exxonsecrets.org, a website showing the links between Exxon money and some of the loudest climate deniers being quoted in the media. The website includes dossiers and fact sheets for each organization and person with a description, history, staff bios, quotes, deeds and hidden affiliations.

July 2005

Environmental and public interest groups launch the “Exxpose Exxon” campaign.


Rex Tillerson becomes Chief Executive Officer of Exxon.

September 2006

The Royal Society, Britain’s preeminent scientific organization, writes a letter to Exxon, inquiring into the company’s promotion of uncertainty around climate change science. The letter comes after the Royal Society meets with Exxon to discuss its funding of climate-denying groups. Exxonpromised at a previous meeting with the Royal Society to stop the funding, but had not followed up after the meeting to explain how it would fulfill the pledge. Later that month, it is reported that Exxon has stopped funding the Competitive Enterprise Institute, a think tank that has actively undermined action on climate change.

2008 (Global CO2 level: 386 ppm, Exxon annual profit: $45.2 billion)

Exxon’s 2007 Corporate Citizenship Report announces that the company will “discontinue contributions to several public policy research groups whose position on climate change could divert attention from the important discussion on how the world will secure the energy required for economic growth in an environmentally responsible manner.” In other words, it will stop funding climate-denying groups. Funding is cut to some climate-denying groups. Funding to others continues.


Greenpeace USA and other citizen groups launch the “Strike Out Exxon” campaign, aimed at stopping the company’s advertisements at Nationals Stadium in Washington.


June 2012

In response to questions following a speech delivered at the Council on Foreign Relations,ExxonMobil CEO Rex Tillerson suggests that while climate change is real, the solution would be to “adapt”:   “[A]s a species, that’s why we’re all still here. We have spent our entire existence adapting, OK? So we will adapt to this. Changes to weather patterns that move crop production areas around — we’ll adapt to that. It’s an engineering problem, and it has engineering solutions.”

January 2013 (Global CO2 level: 396 ppm, Exxon annual profit: $32.6 billion)

The American Legislative Exchange Council (ALEC) pushes the “Environmental Literacy Improvement Act” in Oklahoma, Colorado and Arizona. The model bill mandates teaching the “weaknesses” of the “global warming… theory.” ALEC received consistent funding from Exxon since 1998, and continues to give to ALEC.


Analysis of ExxonMobil Worldwide Contributions and Community Investments reports and ExxonMobil Foundation 990 tax forms reveals that Exxon continues to fund climate denier groups. Between 1998-2014, Exxon gave over $30 million to such groups (Source: Greenpeace and Union of Concerned Scientists). Since 2007, ExxonMobil has also donated $1.87 million to Republicans in Congress who deny climate change.

September 2014

Google’s executive chairman Eric Schmidt announces that the company would not renew its membership to the American Legislative Exchange Council because ALEC is “literally lying” about the fact of climate change. As far as is known, Exxon remains a member of ALEC, serving on ALEC’s Private Enterprise Advisory Council as of August 2015.

February 2015

Research by Greenpeace exposes Willie Soon as having failed to disclose that Exxon and other fossil fuel interests funded his research. Soon had served as one of the few climate deniers with a science background referenced by climate-denying politicians. The news further debunks Exxon’s claim that the company had stopped funding climate deniers in 2007, as Exxon provided more than $300,000 in funding to Soon between 2005 and 2010.

September 16, 2015 (Global CO2 level: 401 ppm, Exxon annual profit: $16.2 billion)

InsideClimate News publishes the first exposé on Exxon’s knowledge of climate change risks and how it responded. The article describes how management at Exxon learned about the potential risk of climate change as early as 1977 and invested in climate change research.

October 9, 2015

The Los Angeles Times and Columbia University’s Graduate School of Journalism publish a story about Exxon’s knowledge of climate threats to the Arctic, including models to anticipate impacts on Arctic operations that Exxon executives such as Lee Raymond would publicly dismiss.

October 14, 2015

U.S. Representatives Ted Lieu and Mark DeSaulnier request that the U.S. Department of Justice launch an investigation into whether Exxon violated the Racketeer Influenced and Corrupt Organizations Act (RICO) as well as laws on consumer protection, truth in advertising, public health, and shareholder protection.

November 4, 2015

New York Attorney General Eric Schneiderman opens an investigation into Exxon over whether the company has lied about what it knew about climate change. The AG issues a subpoena to Exxon demanding in-house documents.

November 20, 2015

Exxon Vice President for Public and Government Affairs Kenneth P. Cohen sends a letter to Columbia University, accusing members of the Graduate School of Journalism  of violating the school’s ethics policies  regarding the recent articles regarding Exxon’s  climate change-related research going back to  the 1970s. The Dean of the Columbia Graduate School of Journalism, Steve Coll,  issues a response defending the articles.

November 23 and 30, 2015

A study in the Proceedings of the National Academy of Sciences finds that organizations that received funding from corporations like Exxon were more likely to argue against climate change science than organizations that did not receive such funding. Another study in Nature Climate Change finds that climate-denying organizations funded by Exxon and the Koch brothers are the most successful at inserting climate denialism into media stories.

January 2016

The U.S. Department of Justice refers the case of Exxon’s advocacy around climate change to the FBI.

January 20, 2016

The Los Angeles Times reports that California’s Attorney General is investigating Exxon over whether the company committed securities fraud or violated environmental laws by lying about what it knew about climate change.

March 29, 2016

A coalition of 17 Attorneys General and AG officials announces their support for President Obama’s Clean Power Plan. As part of the event, the AGs of Massachusetts and the U.S. Virgin Islands announce that they are investigating Exxon’s actions regarding climate change. Top officials from Vermont, Maryland, Virginia and Connecticut say fossil fuel companies would be held accountable for illegal activities around climate change, although they do not announce investigations.

May 18, 2016

13 Representatives sitting on the House Committee on Science, Space, and Technology Committee send letters to 17 state Attorneys General and 8 non-governmental organizations, including Greenpeace. The letters accuse the agencies and organizations of tampering with companies’, organizations’ and individuals’ rights to free speech. Greenpeace USA Executive Director Annie Leonard responds that “America’s least-respected politicians have now courageously stepped up to defend one of America’s most-hated corporations from scrutiny.” Data from Oil Change International shows that the 13 Representatives who sent the letter have received $2,848,418 in campaign contributions from coal, oil and gas companies since 1999.

May 25, 2016

Exxon holds its annual shareholders meeting in Dallas. The board confronts 14 proposed resolutions from shareholders, 10 of which are climate-related. All climate change resolutions are voted down. However, a resolution requiring Exxon to report on the impacts to its business from climate policy receives a substantial 38% vote of support, and a separate resolution passes allowing shareholders to vote in a portion of Exxon’s board of directors. This presents the possibility of getting a climate expert on Exxon’s board.

June 1

Greenpeace USA, other NGOs and the Maryland Attorney General reject the authority of Congressional representatives’ inquiry. Greenpeace notes the “‘irony’ that [the] committee, in the name of protecting ExxonMobil’s free speech, would ‘examine’ the free speech of environmental groups.”

June 9

Nineteen members of California’s Congressional delegation send a letter of support to California Attorney General Kamala Harris, encouraging her investigation into Exxon despite pressure from the House Committee on Science, Space, and Technology Committee to stop.

June 29

The Attorney General of the U.S. Virgin Islands agrees to withdraw his subpoena of Exxon, after Exxon sues the U.S. territory for what the company claims are violations of First and Fourth Amendment rights. The agreement does not prevent the U.S. Virgin Islands from subpoenaing Exxon in the future. Exxon had also sued the Massachusetts Attorney General’s office based on similar arguments, but Massachusetts continues to fight the lawsuit.

July 6

Chairman of the House Committee on Science, Space, and Technology, Congressman Lamar Smith (R-TX), implies he will subpoena the 17 Attorneys General and 8 NGOs if they do not reply to the Committee’s earlier request for their communication records. Greenpeace and 350.org respond by demanding that Congressman Smith and the involved Committee members reveal their connections to the fossil fuel industry, which has given Smith and the other members $2,848,418 in campaign contributions since 1999.

July 11

19 Senate democrats use the chamber floor to highlight the fossil fuel industry’s–including ExxonMobil’s–“web of denial” around climate change. The same day Senator Sheldon Whitehouse (D-RI) and Congressman Ted Lieu (D-CA) introduce a resolution arguing that fossil fuel companies created a “misinformation campaign to mislead the public and cast doubt in order to protect their financial interest.”

July 13

Congressman Smith subpoenas the offices of the New York and Massachusetts AGs and 8 NGOs, including Greenpeace, with a deadline to respond by July 27.

July 27

Attorneys General Schneiderman and Healey, as well as Greenpeace and other NGOs, refuse to respond to the subpoena. “The American people know this Congressional subpoena is Rep. Smith’s signature move to turn attention away from the real issue at stake, which is the investigations into Exxon’s climate denial,” says Greenpeace Executive director Annie Leonard.

August 20

New York Attorney General Eric Schneiderman says in an interview with the New York Times that his office’s investigation into Exxon is focused less on what the company knew about climate change years ago, and more on whether the company in recent years failed to report the potential impact of climate change regulations on its future business. In other words, the AG’s office is conducting “a straightforward fraud investigation.”

September 20

The Wall Street Journal reports that the Securities and Exchange Commission (SEC) is investigating whether Exxon failed to publicly report the potential impact of climate regulations on its future business–the type of investigation also being conducted by the New York Attorney General. The Wall Street Journal reports that the SEC is also investigating whether Exxon failed to “de-book” some of its oil and gas reserves in the face of low oil prices–in other words, that Exxon has been claiming valuable assets that it does not actually have, given the poor state of the oil and gas industry.

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