https://www.theguardian.com/environment/climate-consensus-97-per-cent/2018/sep/19/shell-and-exxons-secret-1980s-climate-change-warnings https://www.theguardian.

https://www.theguardian.com/environment/climate-consensus-97-per-cent/2018/sep/19/shell-and-exxons-secret-1980s-climate-change-warnings https://www.theguardian.com/environment/climate-consensus-97... possibly https://skepticalscience.com/1982-exxon-accurate-prediction.html https://skepticalscience.com/1982-exxon-accurate-prediction.... (totally unverified - lots of links to the sources though)