ExxonMobil had accurate data on global warming since the late 1970s

Harvard researchers show that the fossil fuel company knew about the danger of climate change, but denied it publicly for decades

ExxonMobil global warming
A view of a cracked ground near the Sidi El Barrak dam in Nafza, Tunisia.JIHED ABIDELLAOUI (REUTERS)
Clemente Álvarez

Internal documents released in 2015 showed that, for decades, energy giant ExxonMobil had known about the danger of climate change caused by fossil fuels, although the company then publicly denied that this was a problem.

Eight years later, a new paper in the journal Science analyzes the information that the oil and gas conglomerate had about the consequences of its activities on the climate. It turns out that the firm’s scientific projections anticipated precisely how much the planet was going to warm up from the 1970s until the present.

“This is the first quantitative and systematic evaluation of the climate projections of the fossil fuel industry,” says Naomi Oreskes, a professor of Earth and Planetary Sciences at Harvard University, who is one of the authors of the paper.

“Between 1977 and 2003, the Exxon scientists modelled and predicted global warming with impressive skill and precision. But in public, the company spent decades denying that same climate science.”

In this academic review – developed by researchers at Harvard University, in collaboration with the Potsdam Institute for Research on the Impact of Climate Change in Germany – 32 internal documents produced by ExxonMobil scientists between 1977 and 2002 were analyzed, as were 72 peer-reviewed scientific publications written by ExxonMobil scientists between 1982 and 2014. Ironically, all of this research was financed by the enormously profitable sale of fossil fuel.

Activists protest during the trial against Exxon in the New York courthouse in 2019. "Exxon knew it," says the poster, referring to climate change.
Activists protest during the trial against Exxon in the New York courthouse in 2019. "Exxon knew it," says the poster, referring to climate change.JUSTIN LANE (EFE)

The Harvard researchers found that Exxon’s scientists accurately calculated what was going to happen to the climate, coming to the same conclusions that climate scientists have established.

“Their projections were consistent and at least as good as those of independent academic and government models, in some cases, they were even better,” Oreskes told EL PAÍS via email. “The company’s subsequent public statements contradicted not only the general scientific consensus at the time, but also its own data. We believe this conclusively rules out any claim that ExxonMobil simply had a different interpretation of the data than conventional scientists.”

Today, dozens of US cities, counties and states are suing fossil fuel companies for hiding what they really knew about the climate consequences of greenhouse gases. ExxonMobil managed to fend off a major lawsuit in 2019 in the state of New York, after it was alleged that the firm had lied to its shareholders about the impact of its activities on accelerating global warming.

The researchers say that their findings show that ExxonMobil’s leadership not only knew “something” about global warming decades ago, but knew “just as much” as the other scientists, whose findings they were publicly trying to discredit. In addition, they emphasize that Exxon is by no means the only fossil fuel company that has tried to misinform or hide information to minimize the threat of climate change.

“I think it’s fair to say that we have evidence that all fossil fuel companies were aware of the threat of disruptive climate change from greenhouse gases produced by normal use of their products since the 1970s, or even the 1960s,” Oreskes added. “We also have evidence that other sectors related to fossil fuels – such as car manufacturers – were aware of the problem as early as the 1960s. And we know that other companies funded academic research on the subject at leading universities, such as Columbia, in the 1970s and 1980s.”

ExxonMobil’s internal climate information has been put under the microscope because the oil giant has made a special effort to discredit warnings about climate change. They are one of the companies that employs the world’s best climate scientists.

“Only ExxonMobil seems to have engaged in the level of high-quality science that we are discussing here,” Oreskes pointed out, in reference to the scientists who have worked at the company and have published peer-reviewed studies. “If anyone has evidence that other companies were doing high-level internal science, we would be happy to look at that as well.”

The Harvard professor explains that Exxon crafted “a very sophisticated and quantitatively accurate risk assessment” of climate change, although, for decades, the firm publicly denied that this process could ever be achieved. She stresses that the American company and its lobbyists claimed that the scientific uncertainties were too great to justify political action to stop an alleged warming of the planet, as this would have logically meant a reduction in the consumption of fossil fuels. This was in direct contradiction of Exxon’s own data. “Not one of their models suggested that climate change would not occur,” she said.

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