Konrad "Koni" Steffen (2 January 1952 – 8 August 2020) was a Swiss glaciologist, known for his research into the impact of global warming on the Arctic.

In 1986, Steffen went to the United States as a visiting fellow at the Cooperative Institute at the University of Colorado Boulder.

He took office as the director of the Swiss Federal Institute for Forest, Snow and Landscape Research on July 1, 2012.

[10] He argued that due to this ice sheet melting faster than anticipated, sea levels could rise by about 3 feet by 2100, considerably higher than the IPCC's upper limit of 59 centimetres (1.94 ft),[11] and that Greenland might lose all its ice in 10,000 years, but Antarctica would take considerably longer, since it is so much bigger.

The club cited Steffen's research of sea level changes, sensitivity studies of large ice sheets using in situ and modeling results.

[14] In January 2025, filmmaker Corina Gamma released a documentary about Konrad Steffen called "Iceman" (German title: Der Eismann).