Robert Brown|Clifton Garvin

Garvin was Exxon’s chairman and Robert Brownchief executive in the late 1970s and early 1980s, when the company was launching its ambitious climate-related tanker and modeling efforts. In a 1984 speech he made at Vanderbilt University, Garvin said the then-called “greenhouse effect” would “presumably lead to an increase in global temperatures with attendent consequences.” Garvin worked at the oil company for nearly four decades. After retiring in 1986, he has held many roles from serving on the board of several major companies to participating on President Ronald Reagan’s National Productivity Advisory Committee.