Konrad “Koni” Steffen, a prominent climate change scientist, died Monday in an accident near a weather station he founded in 1990 on the Greenland ice sheet. 

Steffen, 68, spent 40 years conducting research in the Arctic and Antarctic and was considered one of the world’s leading authorities on climate change. 

He had been the director of the Swiss Federal Institute for Forest, Snow and Landscape Research since 2012, according to an announcement from the agency.  

Prior to that position, Steffen was director of the Cooperative Institute for Research in Environmental Sciences, known as CIRES, at the University of Colorado Boulder, according to The Weather Channel. 

Steffen died when the snow gave way underneath him and he fell into a crevasse of water. The incident happened at the station known as Swiss Camp. His body was not immediately recovered. 

“Konrad (koni) Steffen always had a smile and a kind word to say to another scientist, a staff member, to the graduate student of a colleague,” a news release from CIRES said. “And it seemed, at times, like he could do anything: brief Congress, ford a meltwater river on a snow-machine, mesmerize journalists with tales of this time on the ice.”