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season consistently less than 120 days," an Alaska Department of Natural Resources budget document said in March.
While global warming is hurting oil drilling, it's the increased burning of fossil fuels such as oil that causes global warming. In June, the Department of Energy announced that it would spend $270,000 to help Alaska rewrite its rules about how thick ice roads should be.
Permafrost lies under 166 Alaskan towns and 1,700 miles of Alaskan highways. Melting is causing whole chunks of the Alaska Highway to come apart, state officials said at a January global-warming conference.
Permafrost is melting "under forests as well as under buildings and roads," said atmospheric scientist Michael MacCracken, who headed federal climate-change studies in the 1990s.
So far, the greatest effect on forests has come from the spruce-bark beetle, according to Glenn Juday, a professor of forest ecology at the University of Alaska at Fairbanks. The beetle, which kills spruce trees, has long lived in Alaska's forests, but normally takes two years to grow and reproduce; cold spells cut their numbers.
With global warming, however, the beetles now are damaging as many trees each year as they used to ruin in two, Juday said. More than 4 million acres of spruce - Alaska's predominant tree - have been killed, especially on the Kenai Peninsula.
"It's the largest episode of insect-caused tree mortality ever recorded in North America," Juday said.
The spruce-bark beetle isn't alone. Other tree-killing invaders made welcome by warmer weather include the larch soft fly, the aspen leaf miner and the birch leaf roller, Juday said.
As Alaska's climate gets warmer and drier, Juday's studies indicate, black and white spruces, which make up 80 percent of the state's main forests, won't survive. By the turn of the next century, Alaska's forests will resemble the Aspen-treed grasslands along the northern edge of the Great Plains in North Dakota and Montana, Juday said.
Some scientific reports also blame global warming for plummeting herring and salmon populations, Williams said. In the Yukon River, a warm-water parasite has infected salmon and herring, a key food source for marine mammals such as the stellar sea lion.
Warm waters have made Alaska's Bristol Bay salmon runs occur earlier than normal, making it harder for the salmon to survive, said Alaska Department of Fish and Game biologist Slim Morstad.
In addition, warm-weather wildlife, such as moose and beaver, are heading unusually far north, while species that require frigid weather "don't have anywhere to move to," said scientist MacCracken. Marine mammals such as walruses, ring seals and polar bears may soon see their numbers shrink along with the Arctic ice, Weller said.
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