The Seasonality of Future Sea Ice Extent Decline: Implications for Polar Bear Hunting Success

Future abrupt changes in the minimum sea ice extent in the Arctic Ocean is simulated by several Global Climate Models participating in the last International Panel on Climate Change - 4th Assessment, and in particular the NCAR Community Climate System Model - Version 3 (CCSM3). In this paper we take a closer look at the decline in arctic sea ice extent in the spring and early summer, a period that is key for female polar bear and cubs hunting after denning for several months in the peak of winter. The temporal evolution of sea ice extent for all spring and summer months is investigated and compared against trends in the minimum and maximum sea ice extent. Preliminary results from the CCSM3 show very gradual and much less extensive loss in ice extent in the spring season from the same simulations showing abrupt ice extent changes in late summer. Such seasonal differences may seem subtle from a climate perspective but they may plan a critical role in effort to protect habitat of ice-dependent biota, such as polar bears.