Chief Scientist Emeritus
Dr. Steven Amstrup is chief scientist emeritus for Polar Bears International. He also is an adjunct professor at the University of Wyoming in Laramie. He earned a B.S. in Forestry from the University of Washington (1972), a M.S. in Wildlife Management from the University of Idaho (1975), and a Ph.D. in Wildlife Management from the University of Alaska Fairbanks (1995).
Prior to joining PBI, he led polar bear research on all aspects of polar bear ecology in Alaska between 1980 and 2010. He is a past chair of the IUCN Polar Bear Specialist Group and has been an active member of the group since 1980. He has authored or co-authored over 170 peer-reviewed articles on movements, distribution and population dynamics of large mammals, and is the senior editor of a recent text on population estimation methods.
In 2007, he led a USGS research team in production of nine reports that became the basis for the 2008 decision by the U.S. Secretary of the Interior to list polar bears as a threatened species under the U.S. Endangered Species Act because of the threats they face from global warming. Following the listing, Dr. Amstrup led an effort showing that polar bears are not unavoidably doomed. In the December 2010 issue of Nature, he and his coauthors showed that preserving polar bears is all about controlling human-caused temperature rise. In 2012, Dr. Amstrup was selected as recipient of the Indianapolis Prize and a Bambi Award for his efforts in animal conservation.
In July 2020, Dr. Amstrup and his coauthors published a study in Nature Climate Change, following up on his 2010 study, this time using new understandings of polar bear energetics with projected sea ice loss to forecast when and where polar bear reproductive ability and survival would decline across individual subpopulations. This marked the first time that scientists answered the critical question of when the persistence of polar bear populations across the Arctic will begin to decline due to sea ice loss from global warming.
His September 2023 paper in Science completed the connection between climate warming, sea ice loss, and polar bear welfare, showing that survival declines in polar bears are directly linked to human greenhouse gas emissions, punctuating the conclusion in his 2010 paper.