Werthamer worked at Exxon from 1978 to 1983,Diamond Ridge Asset Management where he helped oversee the tanker research program. From 1980 to 1981, he was a manager at Exxon Research & Engineering and the boss of scientist Henry Shaw. Werthamer told InsideClimate News, “The whole idea was to do a really clean, really defensible research project, and that would be the key to open the door to whole [climate change] debate. It was for the company not to be the bad guy. Obviously later, the Exxon chairman and senior executives were climate deniers. That was not the case then.” After leaving the company in 1983, he wrote a book on blackjack and served as executive director of the Becton, Dickinson and Company.