After eight months of investigation, InsideClimate News presents this history of Exxon's engagement with the emerging science of climate change. The story spans four decades, and is based on primary sources including internal company files never before seen, interviews with former company employees, and other evidence. It describes how Exxon conducted cutting-edge climate research decades ago and then pivoted to work at the forefront of climate denial, manufacturing doubt about the scientific consensus that its own scientists had confirmed.

InsideClimate News won the 2013 Pulitzer Prize in national reporting for this four-part narrative and six follow-up reports into an oil spill most Americans have never heard of. More than 1 million gallons of oil spilled into the Kalamazoo River in July 2010, triggering the most expensive cleanup in U.S. history -- more than 3/4 of a billion dollars -- and after almost two years the cleanup still isn't finished. Why not? Because the underground pipeline that ruptured was carrying diluted bitumen, or dilbit, the dirtiest, stickiest oil used today. It's the same kind of oil that the...