A climate scientist who popularized the term “global warming” has died, the AP reports. Wallace Smith Broecker was 87. Columbia University said the longtime professor and researcher died Monday at a New York City hospital. A spokesman for the university’s Lamont-Doherty Earth Observatory said Broecker had been ailing in recent months. Broecker brought “global warming” into common use with a 1975 paper that correctly predicted rising carbon dioxide levels in the atmosphere would lead to pronounced warming.

Broecker was also first to recognize what he called the Ocean Conveyor Belt, a global system of ocean currents circulating water and nutrients. Broecker was born in Chicago in 1931 and grew up in suburban Oak Park. He joined Columbia’s faculty in 1959 and was known in science circles as the “Grandfather of Climate Science.” (An oddly positive twist to climate change is making headlines.)