Predictions made by ExxonMobil’s own scientists in the late 1970s and early 1980s about the impact of fossil fuels on climate change and future global warming were very accurate, however, the multinational energy company continued to cast doubts on climate science and campaign against climate action for years.
Despite its public denials, the major oil corporation worked behind closed doors to carry out an astonishingly accurate series of global warming projections between 1977 and 2003, according to a team of Harvard-led researchers who published their findings in the Science journal.
Researchers from Harvard and the Potsdam Institute for Climate Impact Research showed the accuracy of previously unreported forecasts of Exxon for the first time in the report “Assessing ExxonMobil’s Global Warming Projections.”
Exxon scientists have been at the forefront of climate change research using computer models, the study shows. According to the study, between 63% and 83% of the climate projections reported by Exxon scientists were accurate in predicting subsequent global warming.
“This paper is the first ever systematic assessment of a fossil fuel company’s climate projections, the first time we’ve been able to put a number on what they knew,” said Geoffrey Supran, a research fellow in the History of Science at Harvard University and a co-author of the report.
Exxon “didn’t just vaguely know something about global warming decades ago, they knew as much as independent academics and government scientists did. And arguably, they knew all they needed to know” said Geoffrey Supran, lead author of the study.
“What we found is that between 1977 and 2003, excellent scientists within Exxon modeled and predicted global warming with, frankly, shocking skill and accuracy only for the company to then spend the next couple of decades denying that very climate science.”
The Harvard team found that Exxon scientists created a series of strangely reliable models and analyses predicting global warming from carbon dioxide emissions over the coming years. Exxon especially anticipated that fossil fuel emissions would lead to 0.20 degrees Celsius of global warming per decade, with a margin of error of 0.04 degrees — a drift that has been proven principally accurate.
Nonetheless, there has still not been a detailed review of Exxon’s own climate modeling statistics, Supran noted.
“We now have airtight, unimpeachable evidence that ExxonMobil accurately predicted global warming years before it turned around and publicly attacked climate science and scientists,” said Dr. Supran. “Our findings show that ExxonMobil’s public denial of climate science contradicted its own scientists’ data.”
ExxonMobil’s Response
While ExxonMobil has not addressed the specifics in this paper, the company did respond before the research was published.
ExxonMobil spokesman Todd Spitler said in a statement, “This issue has come up several times in recent years and, in each case, our answer is the same: those who talk about how ‘Exxon Knew’ are wrong in their conclusions.”
The movement to expose what ExxonMobil knew and when has conjoined on social media under the hashtag #ExxonKnew.
“ExxonMobil’s understanding of climate science has developed along with that of the broader scientific community,” said Spitler while adding that “well intended, internal policy debates” have been recast by some “as an attempted company disinformation campaign.”