Reduced sea ice. Sea-ice extent has shrunk by about 5 percent over the past 40 years.
Reference: Weller, G., A. Lynch, T. Osterkamp, and G. Wendler. 1998. Climate trends and scenarios. Pages 157 in G. a. P. A. Weller, ed. Implications of Global Change in Alaska and the Bering Sea Region: Proceedings of a Workshop, Center for Global Change and Arctic System Research, University of Alaska, Fairbanks, Alaska.
