As climate scientists go, Wally Broecker is famous. The 85-year-old geochemist and Columbia University professor not only coined the term “global warming,” but was one of the first researchers to accurately predict how much the Earth’s temperature would change because of fossil fuel burning. He discovered the Ocean Conveyor Belt, which moves water around the globe, and figured out that those currents help regulate the global climate. “He has singlehandedly pushed more under­standing than probably anybody in our field,” one colleague said in a 2012 profile.



But many of Broecker’s colleagues don’t know that the man known as “the grandfather of climate science” once served as the chief scientific advisor to a man known for running a far-right website that publishes countless articles calling climate science a conspiracy and a hoax: Steve Bannon, the former executive chairman of Breitbart and currently President Donald Trump’s chief strategist.

“He was an intense guy,” Broecker told the New Republic in a phone interview. “I actually kinda liked him.”

They worked together on a project called Biosphere 2, a grandiose experiment in building an artificial world. In 1993, Bannon became acting CEO of the $200 million scientific research facility in Arizona, which Bannon once described as a laboratory for observing the future effects of human-caused climate change. At the time, he boasted about Biosphere 2 scientists’ ability “to study and monitor the impact of enhanced CO2 and other greenhouse gases on humans, plants, and animals.”

“He knew what we were doing, and knew we were worried about the consequences of global warming,” said Broecker, who managed and directed Biosphere 2’s scientific operations from Columbia’s Lamont-Doherty Earth Observatory. But Bannon never publicly questioned the science during his time at Biosphere 2, and Broecker never thought twice about it—that is until years later, when he read in the paper that Bannon would be Trump’s right-hand man.