Alaska's not-so-permanent frost
With winters warming eight degrees in three decades, Alaskans face a strange new landscape.
Overlooking the snowcapped mountains and tidewater glaciers around Kachemak Bay, this hamlet of fishermen, artists, and tourists seems the picture of Alaskan charm.Skip to next paragraph
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But beneath the scene of plenty is a landscape parched: Three hot summers have dried local wells and forced the native village of Nanwalek to shuttle in bottled water and ration it. Swaths of spruce forest around Homer and the Kenai Peninsula are brown because of an unprecedented beetle infestation, linked to the warming climate. And snow levels have diminished steadily since 1938.
While much of the world knows global warming as a phrase, Alaska's warming climate is far more palpable. Summers here, as elsewhere, have been warmer and longer; winters are more temperate, with average temperatures climbing eight degrees Fahrenheit in three decades. Alaskans have mowed their lawns in November, golfed in February, and basked in record in record temperatures all summer.
"The most positive comments come from the more longtime Alaskans. They say, 'Heck, we've been through lots of tough winters. We deserve an easy one,'" says Jackie Purcell, meteorologist and weather anchor for Anchorage TV station KTUU.
Computer simulations of climate change have long suggested global warming's effects would be most pronounced at the poles. Researchers have tried to gauge the impact of the climate system's natural variations, and see if they can account for change over the last few decades.
However, most of the warming in Alaska is not due to these natural variations, says Michael Wallace, an atmospheric scientist at the University of Washington. Environmental changes in Alaska "suggest that global warming is playing a role."
The world should take note, adds Gunter Weller, executive director of the University of Alaska's Center for Global Change and Arctic System Research: "We are the canary in the mine shaft." Indeed, melting Alaskan glaciers are shedding twice as much ice as in previous decades. And the Arctic ice pack has thinned by 40 percent since the 1960s.
"There's no greater threat to Alaska's ecosystems and indigenous cultures than global warming. Period," says Deborah Williams, executive director of the Alaska Conservation Foundation. [Editor's note: The original version misstated the number of degrees rivers have warmed up in 20 years and slightly misstated a quote from Deborah Williams.]
Global warming is believed to be the result of rising amounts of carbon dioxide and other "greenhouse" gases in the atmosphere. These trap the earth's radiant heat, creating a greenhouse effect.
The effects are more dramatic here because of the temperature-sensitive overlay of permafrost and glaciers. Thawing permafrost plagues highway crews and operators of the Trans-Alaska Pipeline, which depends on supports to avoid sinking into the tundra. The oil industry has lost half its exploration season to the warmth, which keeps the tundra soft - and unable to support heavy vehicles or drilling equipment - for longer stretches of time.
Large sections of northern forests are collapsing into swamps of melting permafrost; sections of shoreline on the Arctic Coast have thawed, making them vulnerable to storms; and the Arctic's largest ice shelf, solid for 3,000 years, broke up last month due to warmer temperatures - though scientists were hesitant to blame global warming specifically.
"It's more than just mechanical erosion. It's melting of the soil. You can get big collapses of beach bluffs," says Craig George, a biologist with the North Slope Borough.