More than forty years ago, Broecker predicted the existence of climate warming due to human activity. In 1975, he published the article “Climate Change: Are We on the Brink of a Pronounced Global Warming?” in the journal Science, marking the first ever mention of the term “global warming” in a scientific publication. In this text, he also predicted that the rise in anthropogenic CO₂ emissions would weaken the ocean’s ability to withdraw carbon dioxide from the atmosphere, leading to pronounced warming at the start of the 21st century – a prediction that has proved all too true.

The jury deciding the first Frontiers of Knowledge Award in Climate Change praised the radical innovativeness of Broecker’s work, which, it said, had opened up new avenues of research vital to our understanding of climate and its evolution. Special mention went to the laureate’s knowledge contribution with regard to “abrupt changes”; processes which trigger extreme and sudden alterations in the climate system. Today’s rapid thawing of the Arctic polar cap threatens to trigger one such abrupt event: the alteration of the main current distributing heat across ocean basins (the thermohaline circulation, also known as the oceanic heat conveyor belt).

In the words of the citation, Broecker’s “seminal” research into the oceans’ biological and chemical processes “pioneered the development of Earth System Science as the basis for understanding global climate change, both past and present.” It also cited “his holistic approach,” which had led him to identify “the mechanisms of abrupt climate change.”

“Prof. Broecker has been an eloquent educator and a forceful champion of efforts to address the risks of greenhouse gas emissions from human activities,” concluded the jury in its resolution.

Professor Broecker, born in Chicago in 1931, earned his PhD in Geology in 1958 from Columbia University, an institution he remained associated with for much of his career. He was Newberry Professor of Geology in the Department of Earth and Environmental Sciences, as well as a scientist at Columbia’s Lamont-Doherty Earth Observatory, and an Academic Committee member of its Earth Institute.

Among the many recognitions he earned for his contributions to the science of climate change were the Vetlesen Prize (1987), the National Medal of Science from the U.S. government (1996), the Tyler Prize for Environmental Achievement (2002) and the Crafoord Prize (2006). He was author of eleven books and over 500 published papers, in one of which he coined the term “global warming” (“Climate Change: Are We on the Brink of a Pronounced Global Warming?” Science, 1975).

Broecker was a member of the U.S. National Academy of Sciences, the American Academy of Arts and Sciences, the American Geophysical Union, the European Geophysical Union and the UK’s Royal Society.