Guy Stewart Callendar in 1934. An engineer specializing in steam and power generation, he achieved distinction for his many contributions to civilian and, during World War II, military-related engineering. But he is remembered chiefly for his amateur forays into measuring global temperature and carbon dioxide, and contributions to the physics of how carbon dioxide emitted by humanity traps radiation. (This is sometimes called the "Callendar effect"although usually called, misleadingly, a "greenhouse effect".)

University of East Anglia Archive (provided by James R. Fleming).