Born on 9 February 1898 in Montreal, Canada, Guy Callendar was a steam engineer by trade but made his mark in science as a meteorologist and climate scientist. Shortly after he was born, his family moved to England. In 1922 Callendar earned a certificate in mechanics and mathematics from City and Guilds College in London (part of Imperial College) and went to work for his father as a research assistant, studying the physics of steam. After his father died in 1930, Callendar continued to do steam research but also began collecting information on weather and climate. In April 1938 Callendar published his first paper, “The artificial production of carbon dioxide and its influence on temperature,” which appeared in the Quarterly Journal of the Royal Meteorological Society. Although the paper garnered little notice at the time, it has become a classic in the history of climate science because of Callendar’s prescient conclusion linking rising atmospheric carbon dioxide concentrations and global warming. He continued to write and publish about climate until his death in 1964. (Photo credit: G. S. Callendar Archive, University of East Anglia)
