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Evidence of global warming may be subtle enough to overlook or ignore throughout most of the United States, but in Alaska, the signs of climate change are everywhere, and they are dramatic. From the state's Southeast Panhandle to its far northern reaches, Alaska's landscape is being reshaped. Glaciers and sea ice are rapidly melting, boreal forests are being transformed by unprecedented insect outbreaks, permafrost is diminishing, lakes are drying up, Arctic tundra is giving way to woodlands, and coastal areas are being eaten away by fierce storms. As a consequence, many of the state's inhabitants - both human and non-human - are being forced to adapt to new living conditions.
"In Alaska, people are more aware of the warming problem because it's staring you in the face," says Gunter Weller, director of the Center for Global Change and Arctic System Research at the University of Alaska, Fairbanks. "You can't deny the evidence, because it's all around you."
More and more of that evidence is being collected by legions of Alaskan researchers, and it is being experienced first-hand by residents. Among those most directly affected are the Inupiat Eskimos of Alaska's northern coasts, where rising sea levels, thawing permafrost, and increasingly severe storm surges are eroding the ground beneath several villages.
Located on a barrier island just outside Bering Land Bridge National Preserve, Shishmaref is among Alaska's most endangered villages. The bluffs on which the community sits are rapidly eroding, and residents have decided to relocate inland - a hard but necessary choice with huge emotional and economic tolls.
Inupiat hunters are having a harder time harvesting traditional subsistence foods because the ice pack is retreating. The marine mammals on which they depend are more difficult to locate. At the same time, caribou are staying longer on the North Slope and arriving later in fall. "All our hunting, our whole lifestyle, is being affected," says Willie Goodwin, an Inupiat resident of Kotzebue and special assistant for Alaska's Western Arctic National Parklands, which are heavily used for subsistence purposes. "The changes were subtle at first, but now we're very concerned about what we're seeing."
Alaska's Interior-dwelling Athabas-cans have also noticed unsettling changes in either the number or behavior of animals, from white-fronted geese to beavers, according to Orville Huntington, vice chair of the Alaska Native Science Commission. The Yukon River is warming, and increasing numbers of its king salmon are being infected by a parasite. And elders say "winter isn't really winter anymore."
Scientists and indigenous residents aren't alone in their concerns. Even Sen. Ted Stevens (R-Alaska) - hardly an environmental alarmist - recognizes that Alaska has been hard hit by climate change. Industry leaders, too, have been forced to pay attention: The oil industry's winter exploration season on the North Slope has dropped from 200 to 100 days in only three decades.
Climate change is being felt in the Far North first, and most dramatically, because of what scientists call "feedback processes." As the region's abundant snow and ice melt away, increased areas of water and earth are exposed to the sun. Those darker surfaces absorb much higher amounts of solar radiation; as they expand in size, the darker surfaces take in more heat, which accelerates the warming. "Basically the warming builds on itself," says Weller. "It has a magnified effect."
Globally over the past century, the average annual temperature has increased about 1 degree Centigrade; in the Arctic, it has climbed 2 to 3 degrees C (3.5 to 5 degrees Fahrenheit). "That may not seem like much, but it's a huge signal of change," Weller says. Wintertime changes have been even greater, ranging from 7 to 9 degrees F higher in some parts of the Arctic between 1954 and 2004.
Although more moderate climates are lagging behind, scientists agree they are bound to feel the effects if the warming trend persists. "The Arctic is a preview of the Earth's future climatic shifts," says Bob Corell, chairman of the Arctic Climate Impact Assessment (ACIA), a multinational study involving 300 scientists and other experts, including indigenous elders. "It's not a question of 'if'; it's a matter of 'when.'"
It's not surprising, then, that some scientists consider Alaska our country's "early warning system," the proverbial canary in the coal mine of atmospheric warming.
Although some quarters still claim there is not enough scientific evidence to support a global warming trend, both Corell and Weller emphasize that the evidence is now "unequivocal." And Weller says "the evidence is now overwhelming that much of the global warming is due to human-made greenhouse gases" produced mostly by the burning of fossil fuels: oil, gas, coal. He adds, "We [in the science community] are not saying that the sky is falling, but there will be changes. We need to be realistic and assess the risks, vulnerabilities, and opportunities associated with global warming."
Spread across 32 ecoregions, Alaska's 54 million acres of national parklands are being affected by global warming in many ways, some of them obvious, others subtle. As wild landscapes change, plant communities, wildlife populations, and humans dependent on park resources must adapt or lose their niche in the ecosystem. Polar bears are a prime example. They're losing critical habitat-near-shore sea ice-at an accelerating rate. Among the 3,000 to 5,000 polar bears that inhabit Alaska's Arctic lands and waters, a small number follow the ice pack each year into Kotzebue Sound and come aground within two of Alaska's most remote parklands: Bering Land Bridge National Preserve and Cape Krusenstern National Monument. If warming keeps the ice pack from advancing into Kotzebue Sound, polar bears will no longer walk the shores of Alaska's northwest parklands as they have for untold generations.
The disappearance of sea ice is just one example of several climate-related changes that have been documented in and around Alaska's national parklands.
A laska's glaciers are "thinning" at an accelerating rate. From Kenai Fjords to Wrangell-St. Elias and Glacier Bay, glaciers are contributing enormous amounts of meltwater to the oceans. Of 100 glaciers studied in Alaska and Canada, all but three are losing mass, says University of Alaska, Fairbanks geophysics professor Keith Echelmeyer.
Although most of the current sea-level rise is caused by thermal expansion, about 10 percent is from glacial runoff. And Alaska's glaciers are contributing far more than anywhere else on Earth.
Many other changes have been noted throughout Alaska. Here are a few of the most dramatic examples:
- Throughout much of northern Alaska, tundra is becoming brushier and giving way to forest. As tundra diminishes, animals that depend on it for food or nesting habitat - caribou and many birds - are likely to lose out. That appears to be happening on the Seward Peninsula: Musk ox and moose are moving in as woodlands spread, and the caribou traditionally hunted by locals are moving out.
The Denali Caribou Herd at Denali National Park is already down to 1,800 animals. If the north side of the Alaska Range grows brushier and more forested - and there's evidence that this is happening - the herd may die out or move on. The loss of the herd would affect the park's famous wolves, which depend on the caribou.
- Alaska's woodlands have become more susceptible to insect attacks. A series of unusually hot and dry summers, combined with warmer winters and large stands of stressed trees, led to the largest insect infestation in Alaska history. Between 1989 and 1998, nearly 3.5 million acres of forested lands were beseiged by a "super outbreak" of spruce bark beetles. University of Alaska, Fairbanks forest ecologist Glenn Juday has called this an unprecedented "forest-shaping event" whose consequences are still being studied and debated. About 182,000 acres within Wrangell-St. Elias National Park have been affected. With continued warming, scientists predict additional infestations of Alaska's woodlands by a variety of insects.
- As Interior Alaska's climate becomes warmer and drier, the number of lightning-caused fires may increase in number and severity. "Fires are burning 'harder,'" says Park Service landscape ecologist Paige Spencer, "which sets back forest succession."
Even more disconcerting, perhaps, is the accelerated invasion of non-native plants. A prime example is sweet white clover, which loves dry, warm weather. Not so long ago, you could find only occasional clover patches; now it's taking over in some areas, at the expense of willow and cottonwood-and ultimately the moose that eat those plants. "What happens when clover replaces willow-cottonwood habitat?" Spencer asks. "What are the moose going to do?"
- Melting permafrost threatens damage to homes, public facilities, roads, and other structures in many northern communities. In the Tanana Flats south of Fairbanks, forested areas are being transformed into wetlands. Conversely, where subsurface drainage is good, forests previously built on permafrost may dry out, producing grasslands. As with tundra, such ecosystem shifts will yield different plant and animal communities.
- The Bristol Bay region, home to the world's greatest sockeye salmon runs, has experienced unexpected sockeye declines since the mid-1990s. Researchers suggest the decline is climate related. Among the river-and-lake systems most severely affected is the Kvichak River-Iliamna Lake-Lake Clark drainage. Sockeye salmon is "the most important nutritive source in the Lake Clark ecosystem," the heart of Lake Clark National Park and Preserve, says Carol Ann Woody, a fisheries researcher with the U.S. Geological Survey. Once numbering in the millions, sockeye returns to Lake Clark have dropped to 200,000 fish. One of Woody's primary goals is to piece together the puzzle of those sockeye runs. "The models we used to depend on don't work any more," she says. "There's not a single sockeye system where we know what's going on."
Among those affected by sockeye declines are residents whose subsistence diet has traditionally been salmon rich. "It's a very significant concern to these people," Woody says. "They're having to fish longer, fish for other species, and some are still not meeting their subsistence needs."
Given the many climate-connected changes identified in and around Alaska's national parklands, it's only natural that the Park Service would play a key role in global-warming studies. As part of a national "inventory and monitoring program" that's still in its infancy, the Park Service will select "vital signs" for each of Alaska's 17 units, to measure their current ecological health and provide a baseline to measure changes. Inevitably, many of those "vitals" will be indicators of shifting climatic conditions. "Because of the way they're managed, our parks can be used as living laboratories," says Sara Wesser, Inventory & Monitoring (I&M) coordinator for the Alaska region. "Our studies can make important contributions to the science of climate change."
The I&M program will also assist managers as they deal with the changing nature of parklands and their many uses, both in Alaska and nationwide, as climatic conditions shift. No longer do we need to debate whether global warming is "real." Now the key questions become: How severe will the warming - and its consequences - be? And what are we willing to do to lessen our impacts as the Earth heats up.
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Anchorage nature writer Bill Sherwonit is the author of ten books about Alaska.
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