A new report by Inside Climate News reveals how oil giant ExxonMobil’s own research confirmed the role of fossil fuels in global warming decades ago. By 1977, Exxon’s own senior experts had begun to warn the burning of fossil fuels could pose a threat to humanity. At first, Exxon launched an ambitious research program, outfitting a supertanker with instruments to study carbon dioxide in the air and ocean. But toward the end of the 1980s, Exxon changed course and shifted to the forefront of climate change denial. Since the 1990s, it has spent millions of dollars funding efforts to reject the science its own experts knew of decades ago. Scientist Richard Werthamer worked at Exxon from 1978 to 1983, where he supervised Exxon’s carbon dioxide program.

Richard Werthamer: “The implications of increasing carbon dioxide were not that significant for Exxon per se. They were significant because it implied dramatic changes in climate, and that could provoke very substantial legislative consequences that would impact Exxon’s business significantly. You know, if you think that burning fossil fuels is going to flood your cities, well, there’s going to be some national discussion about what to do about it, and one possibility is we’re going to have to burn fewer — less carbon-based fuels.”