Climate Change and the Arctic
Arctic climate is showing signs of rapid change, but extensive study is needed to fully understand the changes and what they may mean to the Arctic and to global climate systems.
Changes beginning in the 1970s and 1980s include:
Most of these trends derive from relatively short environmental records, and the magnitude of the high-latitude temperature increase is no larger than the interdecadal temperature range for the last century. Since climate is naturally variable, the occurrence of an exceptionally warm period may not be abnormal because it may fall well within the expected range of temperature variability for a specific area. However, identified patterns of arctic change agree generally with those predicted by current climate models under scenarios of enhanced greenhouse warming.
The temperature increase at high latitudes partly reflects recent (1990s) atmospheric circulation shifts. In particular, the polar vortex has strengthened and surface pressures in the central Arctic are lower as a result. In turn the normal clockwise circulation of sea ice in the Beaufort Sea (the Beaufort Gyre) has weakened. Other changes linked to observed shifts in atmospheric circulation are:
(Material for this section was drawn from Serreze et al. (2000); Rothrock et al. (1999); and the National Science Foundation's Arctic Systems Science program's Report on the Arctic Change Workshop, (1998).)