Sea ice across the Arctic is declining and altering physical characteristics of marine ecosystems, and polar bears are vulnerable to these changes in sea ice conditions. Stephen Hamilton from University of Alberta and colleagues used sea ice projections for the Canadian Arctic Archipelago from 2006-2100 and metrics developed from polar bear energetics 5 modeling to gain insight into the conservation challenger for polar bears facing habitat loss. Shifts away from multiyear ice to annual ice cover throughout the region, as well as lengthening ice-free periods, may become critical for polar bears before the and of the 21st century with projected warming.