A review of 187 ExxonMobil documents, published by two Harvard researchers on Wednesday, has found that the company ”misled the public” on climate change.

The documents included internal papers published by journalists at InsideClimate News as well as 50 “peer-reviewed articles on climate research and related policy analysis” written by ExxonMobil researchers. The oil and gas company made the internal papers public and challenged anyone to “read all of these documents and make up your own mind,” accusing journalists of cherry-picking data.

Geoffrey Supran and Naomi Oreskes, from Harvard's Department of the History of Science, took up that challenge, comparing the information in the documents cited by ExxonMobil against the information conveyed in the publicly-available advertorial columns published by the company on anthropogenic (or human-caused) climate change in the New York Times. They found that “83 percent of peer-reviewed papers and 80 percent of internal documents acknowledge that climate change is real and human-caused, yet only 12 percent of advertorials do so, with 81 percent instead expressing doubt.”

The research comes at a tricky time for ExxonMobil, when Attorneys General from 17 states as well as the officials at the Securities and Exchange Commission have launched investigations of the company due to allegations that ExxonMobil misled the public and investors on the risks of anthropogenic climate change. Recently, investors voted that the company should produce an annual report on the risks that climate change policies might pose to ExxonMobil’s global businesses, despite opposition from the company’s executives.

"Stranded fossil fuel assets"

The Harvard analysis, published this week in the journal Environmental Research Letters, focused on communication and research produced by ExxonMobil between 1977-2014. The researchers compared the internal and research reports to a couple dozen advertorials placed by ExxonMobil in the New York Times during those years. Advertorials (meaning, paid-content columns written in the style of opinion pieces) were chosen to represent ExxonMobil's communication with the public because the columns “come directly from ExxonMobil and are an unequivocally public form of communication” designed to affect public opinion.

The researchers then used a detailed "point" system to assess the advertorials. With their numbered ratings, they were able to sort them based on whether they expressed reasonable or unreasonable doubt of climate change. “We recognize that all science involves uncertainties, and therefore that doubt is not, ipso facto, an inappropriate response to complex scientific information,” the researchers wrote. Advertorials expressing doubt of climate change that were published on or before 1990 were considered to express a reasonable doubt. On or before 1995, the researchers considered doubt over human-caused climate change to be reasonable. (The researchers stress that these are conservative thresholds.)

Similar analysis is applied to internal knowledge vs. external communication on the impacts of climate change, and the possibility of climate change and policy leading to “stranded fossil fuel assets,” which would affect investors.

The paper states that ExxonMobil does not appear to have “suppressed” climate science. Instead, ”in public, ExxonMobil contributed quietly to the science and loudly to raising doubts about it.“

“On the question of whether ExxonMobil misled non-scientific audiences about climate science, our analysis supports the conclusion that it did,” the researchers write. “Internal documents show that by the early 1980s, ExxonMobil scientists and managers were sufficiently informed about climate science and its prevailing uncertainties to identify AGW [Anthropogenic Global Warming] as a potential threat to its business interests.”

The researchers also note that to find all of ExxonMobil’s scientific climate studies, they required access to Harvard and Massachusetts Institute of Technology libraries, as well as international interlibrary loans—a level of research support that a layperson would not generally have.

Ars contacted Exxon, but the company did not respond to a request for comment. To Reuters, Exxon spokesperson Scott Silvestri "said the researchers' study was ‘inaccurate and preposterous’ and that their goal was to attack the company's reputation at the expense of its shareholders.”