Big Oil Deceived the Public for Decades About Climate Harms, But Accountability Remains Elusive
With the Trump administration backsliding on climate action, holding oil companies accountable for worsening the climate crisis is “more important than ever,” a new report argues.
A Chevron ad in the DC airport misleadingly claims the company is “working hard for a lower carbon future” and that it is holding itself accountable. Credit: Dana Drugmand
Dozens of cities, counties, and states across the US – from California to Chicago to Charleston – are taking the fossil fuel industry to court in a wave of tobacco-style litigation as the damaging impacts and staggering costs of the fossil fueled-climate crisis continue to mount. While the lawsuits vary somewhat in terms of their legal claims asserted and remedies sought, they are all generally grounded in the understanding that Big Oil – like Big Tobacco before it – deceived the public for decades about the dangers of its products in order to boost profits. But unlike the tobacco industry, the fossil fuel industry has yet to be held accountable for its malfeasance, and it currently is riding high on the support of the Republican-controlled federal government that is attacking clean energy and climate science.
Now, a new report has laid out much of the evidence that has emerged over the last decade demonstrating what and when Big Oil knew about climate change and what it did with that knowledge, evidence suggesting that companies like ExxonMobil and Shell could be held liable for ensuring that society remained hooked on fossil fuels despite being warned about the catastrophic climate consequences.
“At a time when the federal government is backsliding on climate action and pandering to fossil fuel interests, it is more important than ever to hold these corporations accountable for exacerbating the climate crisis,” the report released on May 14 by the Union of Concerned Scientists (UCS) argues.
Titled “Decades of Deceit,” the report examines and synthesizes the evidence underpinning the climate deception lawsuits brought against Big Oil, providing an analysis of the legal and scientific case supporting accountability for the industry. The evidence comes from internal corporate documents uncovered through methods such as investigations and scholarly research, and the report adds to a growing evidentiary record substantiating allegations of industry fraud and deception.
“The report builds on the diligent efforts of many social scientists, investigative journalists, litigators, members of Congress and researchers on congressional committees, and public interest groups working to hold fossil fuel companies accountable,” said Kathy Mulvey, report co-author and accountability campaign director for the climate and energy program at Union of Concerned Scientists. “We put it together because there’s been so much evidence pouring in, both about what the fossil fuel industry knew decades ago about harms that their products and business model would cause, and what they did with that knowledge to embark on a campaign of deception.”
To briefly recap some of the historical evidence:
1950s: In 1959, physicist Edward Teller gave the keynote speech at an American Petroleum Institute (API) event marking the oil industry’s 100th birthday. Teller warned industry executives about the impact of fossil fuel combustion on climate, including the prospect of melting polar ice caps and sea level rise inundating coastal cities.
1960s: In 1965 at the annual meeting of the American Petroleum Institute, then-API president Frank Ikard summarized the main findings of an environmental report from President Lyndon Johnson’s scientific advisers. He said the report found that fossil fuel combustion was adding carbon dioxide to the atmosphere at such a rate that by 2000 it could cause “marked changes in climate beyond local or even national efforts.” Ikard further noted the report warned that “time is running out” to save the world’s peoples from “catastrophic consequences” of fossil fuel pollution.
1970s: In the 1970s, Exxon and other major oil and gas companies were conducting research on the effects of fossil fuel usage on the climate system, and were internally acknowledging or being briefed on the potential climate consequences of their products. In 1979, for example, an internal Exxon memo, which summarized findings of a report studying the potential impacts of fossil fuel combustion on CO2 concentrations, acknowledged that “CO2 buildup in the atmosphere is a worldwide problem” and that limiting fossil fuel use would be necessary to prevent “significant climatic changes”.
1980s: Internally, oil companies issued more warnings and further discussed potential consequences of global warming. A 1981 memo from Exxon’s Roger Cohen, for example, stated “it is distinctly possible” that a warming scenario could “later produce effects which will indeed be catastrophic (at least for a substantial fraction of the earth’s population).” In 1988, Shell issued a confidential report that warned that unchecked warming “could create significant changes in sea level, ocean currents, precipitation patterns, regional temperature and weather. These changes could be larger than any that have occurred over the last 12,000 years. Such relatively fast and dramatic changes would impact on the human environment, future living standards and food supplies, and could have major social, economic, and political consequences.” Another confidential Shell publication from 1989 discussed the potential for climate-induced human migration and warned of an “unprecedented” climate refugee problem. “Conflicts would abound. Civilization would prove a fragile thing,” the report stated.
Despite these warnings, the industry strategically organized a campaign to publicly sow doubt about climate science and deny the severity or even the existence of global warming. This involved tactics such as funding contrarian scientists and think tanks disseminating climate denial, and lobbying to block climate policies at all levels. “Major oil companies embarked on a campaign of deception, diversion, and delay to try to foil government and public demands for change,” the UCS report explains. An internal 1998 “Victory” memo, for example, shows how a coalition led by API developed a strategic communications plan to target average citizens and media by overemphasizing and misrepresenting the uncertainties in climate science.
The industry has since pivoted from outright denial of climate science to greenwashing and other narratives and campaigns intended to delay serious climate action and stymie the transition away from fossil fuels. A multiyear congressional investigation has uncovered considerable evidence suggesting that the industry’s duplicitous conduct is ongoing. The investigation culminated in a joint staff report released last year by Democrats on the House Oversight Committee and Senate Budget Committee.
“The industry’s outright denial of climate change has evolved into a green-seeming cover for its ongoing covert operation—a campaign of deception, disinformation, and doublespeak waged using dark money, phony front groups, false economics, and relentless exertion of political influence—to block climate progress,” said Senator Sheldon Whitehouse, former chair of the Senate Budget Committee.
During a committee hearing on May 1, 2024 discussing this landmark investigation, Sharon Eubanks, the former Justice Department lawyer who led the government’s successful civil racketeering case against Big Tobacco, testified that the pattern of deceptive conduct from the fossil fuel industry is strikingly similar to that of the tobacco industry. “Both industries lied to the public and regulators about what they knew about the harms of their products and when they knew it,” Eubanks said. She told the committee she believes there is “certainly an adequate legal foundation for litigation” against the oil industry, including a potential federal case akin to the one brought against tobacco. Following her testimony, Sen. Whitehouse and Rep. Jamie Raskin made a formal referral on May 22, 2024 to then-Attorney General Merrick Garland urging the Department of Justice to open an investigation into fossil fuel industry deception.
Fast forward a year later, and the DOJ under President Trump has now been instructed to go after states for their efforts to hold fossil fuel companies accountable for climate damages. An April 8 executive order calls out polluter pays climate superfund laws enacted in New York and Vermont as well as states that have “sued energy companies for supposed ‘climate change’ harm” and directs the Attorney General to “expeditiously take all appropriate action to stop” these state laws and lawsuits. On May 1, exactly a year to the day after Eubanks testified that there is adequate basis for a federal probe of Big Oil, DOJ announced it had brought lawsuits against four states – New York, Vermont, Hawaii, and Michigan – to try to block their legislation and planned litigation targeting major fossil fuel polluters. Additionally, industry lobbyists are lobbying Congress for legal protection from climate liability lawsuits and legislation.
“It’s clear from the efforts of the fossil fuel industry and its allies in the Trump administration and Congress that they are really threatened by the prospect of legal accountability, and by advances in climate litigation,” Mulvey told me.
As the UCS report points out, “legal action against the fossil fuel industry is gaining traction.” Several of the lawsuits filed by states and municipalities are in the pre-trial discovery phase, during which even more internal documents and damning evidence of corporate malfeasance are likely to be uncovered. If any of the lawsuits do get to a jury trial, fossil fuel companies could actually face accountability and, potentially, massive monetary damages.
Some companies even disclose that possibility in their annual financial reports filed with the US Securities and Exchange Commission. BP, for example, notes in its 20F filed March 2025: “If such suits were successful, the cost of the remedies sought in the various cases could be substantial.” And Chevron states in its latest 10-K filing: “there can be no assurance that the cases will not have a material adverse effect on the company’s results of operations and financial condition.”
It remains to be seen whether the court cases will result in accountability for this industry, as there is still a long battle ahead in litigation that has, in many cases, dragged on for years. But keeping up the pressure through accountability campaigning is essential, especially at a time when the federal government under Trump is unwinding climate and environmental protections at the behest of Big Oil, the UCS report argues.
“With the federal government backsliding on climate, clean energy, and clean transportation—and apparently prepared to grant the fossil fuel industry’s every wish—corporate accountability campaigning is an essential tool,” the report asserts.
“Because the climate crisis is so severe and affecting people and communities everywhere,” Mulvey said, “and with the US federal government backsliding under this administration, using litigation and legal levers is going to be critical.”