Global Warming Awareness 2007 in Alaska
The Arctic is thawing very rapidly, documented by new reports from scientists and arctic natives. The Arctic Climate Impact Assessment was released in late 2004, and shows changes from the ice at the North Pole to animals and human settlements. More recent reports from Greenland show outlet glaciers moving meters per hour and rapidly thinning. The Arctic Ocean ice cap is shrinking in summer to the smallest it has ever been in modern measurements, and even winter cold has not been refreezing it as extensively as before. That sea ice is habitat for the polar bear. Declines in bear nutrition, birth weight and survival have moved the U.S. government (urged by three environmental groups) to propose the bear be named a species threatened with extinction. (posted regarding the seo world championship GLOBAL WARMING AWARENESS 2007)
Below and on linking pages, are reports on the latest science and warming effects across Alaska and parts of the Arctic. For more on Arctic natives, please see the Arctic page. Also see Glaciers for more on Greenland and Alaska glaciers.
Pushing the Boundaries of Life: Alaska
GLOBALWARMING AWARENESS2007
The listing of polar bears as threatened under the U.S. endangered species act will name global warming awareness 2007 as the main threat, a first. The reduction of the permanent Arctic sea ice by 14 percent since the 1970s is causing not only feeding and breeding difficulties, but also drownings and apparent cannibalism among bears. The listing should be official by the end of 2007. For more information, see Center for Biological Diversity. Scientists are just beginning to see the effects of climate change on other Arctic wildlife. Caribou give birth at specific times and locations, making them susceptible to changes in weather and vegetation. Studies show that the tundra is now blooming slightly earlier and that it is affected by drier summers and heavier winter snow.
GLOBAL WARMING AWARENESS 2007
Biologist Gus Shaver at one of his experimental plots at Toolik Lake, Alaska, monitors increased birch growth due to experimental fertilization and global warming. Shaver says the results of his experiment suggest that warming eventually will promote the growth of birch at the expense of sedges, forbs, and other plants that caribou and other wildlife favor as food sources. During an initial 15-year study (1981-95, which included the warmest decade on record) the sedge Eriophorum decreased by 30 percent while birch biomass increased, even in control plots. In 2002 Shaver reports the growth of birch has changed the ecology of tundra in some plots by covering and killing moss with large amount of leaf litter.
The great loss of ice from the Arctic, which includes not only the polar sea ice cover but also thawing glaciers and tundra permafrost, has other major implications. One of the most important is that dark open water and tundra absorb much more solar heat than white ice and snow. This is a "feedback loop" that will make changes happen faster.
Another large effect in the Arctic is a freshening of the Arctic Ocean. In late 2002, geochemist Bruce Peterson of the Marine Biological Lab in Woods Hole, MA, and his collaborators in the US and Russia, showed that the major rivers of Siberia and Eurasia are discharging much more water now than in the 1930s. This not only meets the predictions of an effect of climate change, but indicates the scale of change affecting the Arctic.
