Harvard Study Finds ExxonMobil Scientists Accurately Predicted Climate Change, Despite Denial


A Harvard-led team of researchers found in a study published earlier this month that internal ExxonMobil projections accurately predicted human-caused climate change even as the company downplayed its risks in public statements.

The study, published in Science Magazine on Jan. 13, found that 63 to 83 percent of ExxonMobil scientists’ climate models accurately projected subsequent global warming, including estimated levels of carbon dioxide that would cause “dangerous warming” and detectable human-caused climate change by approximately 2000.

Researchers analyzed internal global warming projections by ExxonMobil scientists between 1977 and 2003 as well as peer-reviewed published studies by the company’s scientists from 1982 to 2014, testing the company’s predictions against climate observations as well as independent academic and government models.

History of Science professor Naomi Oreskes, the study’s co-author, said in an interview that the researchers found the ExxonMobil climate projections were “extremely skillful,” with accuracy that often matched or exceeded models by independent academics and government scientists.


The researchers wrote that despite the accuracy of climate change projections by ExxonMobil scientists, the company denied climate science in its public communications by “overemphasizing uncertainties” about climate change and “feigning ignorance about the discernibility of human-caused warming.”

“We’re able to show that there were massive discrepancies between how ExxonMobil presented the issue in private versus how they presented it in public,” Oreskes said.

In an emailed statement, ExxonMobil spokesperson Todd M. Spitler wrote that the Harvard-led study and other reports claiming the company’s early awareness of climate change “are inaccurate and deliberately misleading.”

“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,” Spitler said. “For more than 40 years, we have supported development of climate science in partnership with governments and academic institutions. That work continues today in an open and transparent way.”

Former History of Science research associate Geoffrey J. S. Supran, the study’s lead author, said in an interview that he believes the study is the “smoking gun” that proves ExxonMobil knew about climate change early on despite its public communications downplaying the phenomenon. He added that it was important to “put a number” on the accuracy of the company’s internal reports.

“They say a picture paints 1000 words, and this one shows how Exxon knew and misled on climate,” Supran said. “This basically seals the deal or closes the case on what Exxon knew and when.”

Oreskes said the study suggests disinformation from fossil fuel companies is to blame for climate inaction, rather than a lack of public scientific literacy.

“What was really going on was a massive, well-organized, and highly professional, very well-funded propaganda campaign,” Oreskes said. “Climate change is one of the easiest scientific concepts to explain, but we were facing a massive disinformation campaign.”

The study serves as a warning for public belief in industry-led research, Oreskes added.

“They say that they are committed to being part of the solution, but we don’t think that’s true,” Oreskes said. “We think if you look at the evidence, what you see is that disinformation continues, and so that’s why we’re motivated to continue to study it.”

—Staff writer Sabrina R. Hu can be reached at Follow her on Twitter @sxbrinahhu.

— Staff writer Jeffrey Q. Yang can be reached at Follow him on Twitter @jeffreyqyang