John Bengtson, National Marine Mammal Laboratory, Bendan Kelly, Executive Office of the President Joel Clement, Department of the Interior
Satellite records showed another record retreat of arctic sea ice in 2012, reinforcing the rapid downward trend in ice extent in the Arctic Ocean. The six lowest seasonal minimum ice extents since 1979 have all occurred in the past six years (2007 to 2012). Probably the most visible indicator of global climate change, sea ice loss contributes to changes in Alaska’s ecosystems and access to resources, and potentially impacts climate across the northern hemisphere. New predictions indicate the Arctic Ocean could be free of ice in the summer as soon as 2020. We need more detailed pictures of what to expect—and when—so we can better prepare and adapt to such changes.