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A
warming Arctic climate may be contributing to the declining
population of guillemots.
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On
average Alaska has warmed by about 4 degrees Fahrenheit over the
last 150 years. There
are widespread consequences such
as melting glaciers and insect-devastated forest in
response to this temerature change. Scientists say Alaska is like
a canary in a coal mine, foreshadowing
the types of changes we can expect
for the rest of the world.
Alaska's
own canaries may be the seabirds on Cooper Island, a few miles from
Barrow, the northernmost town in the United States. George Divoky
of the University of Alaska, Fairbanks has spent the last 28 summers
on the island, studying guillemots. Since the 1990s, the colony
has been in steep decline-down more than a third from its peak.
Divoky says a warming climate is to blame.
The
guillemots depend on small, oily fish called Arctic cod, which live
near the sea ice of the Arctic Ocean. But in recent decades the
sea ice has receded farther off shore every summer, making it harder
for the guillemots to find food. Native
hunters and many animals, from whales to polar bears, also depend
on the Arctic sea ice, so climate change seriously threatens their
future. Meteorologist John Walsh, also of the University of Alaska,
shows Alan computer climate models that predict an Arctic Ocean
completely ice-free in summer by the end of the century.
Disappearing
sea ice is one reason the Arctic is warming more than lower latitudes,
because white Arctic ice normally reflects the sun's heat into space,
whereas dark, open water absorbs heat. This change has more than
local significance, because the cooling provided by the earth's
polar regions now is being reduced, accelerating the warming of
the global climate.
For
more on this topic, see the web feature:
Arctic Species at Risk
The Arctic: Our Global Thermostat
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