declines in some salmon stocks, an increase in human health prob-
lems as new diseases move north, and increased forest fires. According
to the IPCC, Northern Hemisphere annual snow cover extent (SCE)
has decreased by about 10 percent since 1966; longer regional time-
scales suggest that Northern Hemisphere SCE over the past decade has
been the lowest in 100 years.
The IPCC notes that other changes in terrestrial ecosystems
include “northward movement of the treeline, reduced nutritional
value of browsing for caribou and moose, decreased water availability,
and increased forest fire tendencies. There are altered plant species
composition, especially forbs and lichen, on the tundra.” And, as the
people of Little Diomede can attest, permafrost is warming and start-
ing to melt. The IPCC notes that “multi-decadal increases in per-
mafrost temperature have been reported from many locations in the
Arctic, including northern and central Alaska, and Siberia”—although
it again offers the caveat that such increases are not uniform and that
parts of the eastern Arctic have experienced a permafrost cooling.
As with the land, so it is with the sea. The IPCC notes, for exam-
ple, that: “Data gathered from submarines indicate that sea-surface
temperature (SST) in the Arctic basin increased by 1 degree C [1.8°F]
over the past 20 years, and the area of warm Atlantic water in the polar
basin increased by almost 500,000 kilometers [193,000 square miles].
Field measurements in 1994 and 1995 showed consistent Arctic sea-
water warming of 0.5 to 1 degree C [0.9 to 1.8°F], with a maximum
detected in the Kara Sea.” (The IPCC does note, however, that it “is not
yet clear whether these changes are part of low-frequency natural vari-
ability or whether they represent the early impacts of long-term climate
change.”)
A series of studies have pointed to decreases in the extent and
thickness of sea ice—literally, the frozen surface of the sea—in the
Arctic. Throughout the Arctic, sea ice extent diminished by about 3°F
per decade between 1978 and 1996: That is about 143,000 square
miles—an area almost as large as Montana—every 10 years. In the
Atlantic part of the Arctic Ocean, the extent of summer sea ice has
shrunk by 20 percent over the last 30 years, and spring sea ice extent
in April in Nordic seas has been reduced by 33 percent over the last 135
Alaska and the Western Arctic 107