news.yahoo.com/s/nm/20050928/sc_nm/environment_alaska_dc
Reuters Alaska landscape transformed by warmer climate By Yereth Rosen Wed Sep 28, 4:38 PM ET ANCHORAGE, Alaska (Reuters) - Sinking villages perched on thawing permafr ost, an explosion of timber-chewing insect populations, record wildfires and shrinking sea ice are among the most obvious and jarring signs that Alaska is getting warmer as the global climate changes, scientists say.
Click Here "We are the canary in the mine, unfortunately, and the harbinger of what is yet to come for the rest of the world," said Patricia Cochran, execut ive director of the Anchorage-based Alaska Native Science Commission. Atmospheric temperatures in the remote state have risen 36 to 54 degree s Fahrenheit (2 to 3 degrees C) over the past five decades, according to the recently released Arctic Climate Impact Assessment, a comprehensive study by scientists from eight nations.
Many scientists believe the earth is warming because of the release of gr eenhouse gases such as carbon dioxide that trap solar heat in the atmosp here. A massive beetle infestation has swept through millions of acres (hectare s) in south-central Alaska over the past decade, scientists said, becaus e significantly warmer weather is delaying the usual winter die-off of i nsect populations. The insects' voracious attack on spruce bark has left forests tinder-dry while general heat-induced stress have weakened forests, with lightning strikes making them a fire hazard in the Chugach Mountain foothills, sai d Glenn Juday, a professor of forest ecology at the University of Alaska Fairbanks. "All the trees in the boreal forest are showing unusual symptoms of warmt h-related health problems," Juday said, noting that Alaska had its bigge st and third-biggest fire seasons in the past two summers. SINKING TOWNS In the cooler interior regions, buildings are slumping and roads are buck ling as permafrost -- frozen soil -- thaws and turns into softer, spongy soil. The Inupiat village of Shishmaref on a narrow Chukchi Sea barrier island is preparing to move as the town sinks into the ground. "For those of us who live in the changing conditions every day, there's n o question.
Shrinking sea ice has created hardships for sea animals like polar bears that find their prey at the ice's edge. Heated-up waterways are throwing off long-established salmon cycles and, according to one scientist, have allowed a warmth-loving, salmon-wreckin g parasite to thrive in the Yukon River. Warming is accentuated in high-latitude regions like Alaska in part becau se of thinner atmospheres in the polar region, concentrating greenhouse gases, and in part because of the nature of atmospheric currents, accord ing to studies. Such changes have also contributed to falling ice coverage in the Arctic Sea, with spring and summer melting happening 17 days earlier than usual , according to the satellite study. The disappearance of ice and snow uncovers dark surfaces of the ground an d sea, which absorb more solar heat and warm up the landscape, said Vlad imir Romanovsky, a permafrost expert at the University of Alaska Fairban ks' Geophysical Institute.
miles, the lowest extent yet recorded in the satellite record. New satellite ob servations show that sea ice in the Arctic is melting faster while air t emperatures in the region are rising sharply, scientists say. Since 2002 , satellite data have revealed unusually early springtime melting in are as north of Siberia and Alaska. Now the melting trend has spread through out the Arctic, according to a national collaboration of scientists stud y released by the University of Colorado at Boulder's National Snow and Ice Data Center statement released Wednesday Sept.
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