Nature - Alaska Warming Faster Than Any Other Region On The Planet

[hatrack]

Alaska's climate: too hot to handle
2 October 2003

"Alaska is warming up more than anywhere else on Earth. Climate researchers are now turning to regional models to find ouw why -- and how to deal with it. John Whitfield went north to investigate.

The vast forests that cover southern Alaska should be evergreen. But not these days. Hop into a tiny plane - which Alaskans seem to do as often as a New Yorker hails a cab - and you'll see patches of brown stretching for miles into the wilderness. This is the work of the spruce bark beetle, which over the past 15 years has killed more trees in Alaska than any other insect in North America's recorded history. In the Kenai Peninsla on Alaska's southern coast, some 40 million spruce have perished across an area twice the size of Yellowstone National Park. The beetle's population rockted thanks to changes in the weather, argues Ed Berg, an ecologist with the Kenai National Wildlife Refuge. 'We had a really long run of warm summers,' he says.

The beetle boom is one of the more dramatic that locals and scientists attribute to global warming. But it's just one in a long list. Farther down the coast in Prince William Sound, boats pick their way through increased numbers of icebergs calving off the Columbia Glacier. The glacier has retreated 12 kilometres over the past 20 years, and some say it could collapse completely in another ten. Alaska's notorious mosquitoes, so big they're jokingly referred to as the state bird, have spread north to irritate the few residents who used to escape their attentions. Even the plants are changing. The spongy tndra, usually covered in grass and moss, is slowly being invaded by woody shrubs (1).

EDIT

Temperatures have changed more in Alaska over the past 30 years than they hae anywhere else on Earth: winters have warmed by a startling 2-3C, compared with a global average of 1C. That's guaranteed to have dramatic effects in an Arctic landscape, where even small temperature changes can make the diffeence between freezing and melting. In Fairbanks, a city built on permafrost, the annual mean temperature is just -2C. If it pops above zero, residents can say goodbye to the frozen ground beneath their feet, along with the free iceboxes in their basements. The impacts on wildlife, and the people who depend on it for their livelihoods, will be huge.

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It is also hard to tell how much of Alaska's climate change is due to global warming and how much to natural climate cycles. The Pacific Decadal Oscillation - an El Nino-like fluctuation of temperatures between the north and tropical Pacific that takes place over 20-30 years - flipped Alaska into a warming phase in the 1970s. The North Atlantic Oscillation has also contributed to warmer winters in Alaska since the late 1960s (4). But at the same time, it has been associated with a 2-3C cooling just across the continent in Greenland. There seems to be a 60-year see-saw in temperatures between the east and west of this part of the Arctic: when one side heats up, the other cools down. In a few years, this could flip again and reverse Alaska's recent warming trend. No one yet knows."

EDIT

http://www.nature.com/nsu/030929/030929-8.html

[ozone_man]

1. I saw this spruce bark beetle damage in the Kenai this year.

I vacationed up in Alaska this August. 2-3C is quite a large temperature rise.