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Canary in a Coal Mine  
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Photo of  guillemots
 

A warming Arctic climate may be contributing to the declining population of guillemots.

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.
Photo of George Divoky

George Divoky of the University of Alaska, Fairbanks has spent the last 28 summers on the island, studying guillemots.

 

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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