Exxon Knew Everything There Was to Know About Climate Change by the Mid-1980s—and Denied It

http://www.thenation.com/article/exxon-knew-everything-there-was-to-know-about-climate-change-by-the-mid-1980s-and-denied-it/
"as early as the late 1970s, Exxon scientists were briefing top executives that climate change was real, dangerous, and caused by their product."