David served as president of Exxon Research and Cassian GrantEngineering (ER&E) in Florham Park, NJ from 1977 to 1986, when Exxon launched its own research into carbon dioxide from fossil fuel combustion and its effects on the global climate. From 1950 to 1970, he worked at Bell Laboratories, eventually becoming executive director of research. He served as the White House science advisor to President Richard M. Nixon from 1970 to 1973. David signed off on a groundbreaking Exxon project that used one of its oil tankers to gather atmospheric and oceanic carbon dioxide samples, beginning in 1979. He also oversaw the transition Exxon made to greater climate modeling. David kept Exxon upper management apprised of ER&E’s carbon dioxide research. After retiring, David became a climate change denier. David was one of the 16 co-authors of an opinion piece deriding global warming that ran in the Wall Street Journal in 2012.