The Associated Press reports that U.S. District Judge Claudia Wilken has given the Department of the Interior 16 days to decide whether to list the polar bear as a threatened species. The judge ruled that the department was in violation of a law requiring a determination by January 9, and gave the department until May 15 to decide. Various environmental activist groups have been pushing for the polar bear to be listed on the theory that global warming will cause summer ice in the Arctic to disappear and prevent polar bears from reaching their primary food supply—seals.
Earlier this month, a Canadian scientific committee declined to advise the Canadian government to list polar bears as threatened or endangered, though it did say that declining sea ice is a reason to be concerned about the polar bear population.
Does a 10 percent reduction in sea ice result in a 10 percent reduction in polar bears? There’s lots of models, lots of predictions, lots of projections, and the committee felt that there is still sufficient uncertainty ... to determine how precisely polar bears might be affected by reductions in sea ice.
H. Sterling Burnett of the
Comprehensive research demonstrates that since the 1970s — while much of the world was warming — polar bear numbers increased dramatically to approximately 25,000 today (higher than at any time in the 20th century). Research conducted by the World Wildlife Fund shows that of the 20 distinct polar bear populations worldwide only two — accounting for about 16.4 percent of the total number of bears — are decreasing. Those populations are in areas where air temperatures have actually fallen, such as the
Baffin Bayregion. By contrast, another two populations — about 13.6 percent of the total — are growing, and they live in areas were air temperatures have risen.
Evolutionary biologist and paleozoologist Susan Crockford, of
Canada’s , points out that polar bears have historically thrived when temperatures were warmer than today’s — during the medieval warming 1,000 years ago and during the Holocene Climate Optimum 5,000 to 9,000 years ago. Universityof Victoria
Polar bears thrive during warmer climates because they are omnivores, like brown and black bears. Though seals are currently their primary food source, research shows that they have a varied diet and take advantage of other foods when those are available. Their diets can include fish, kelp, caribou, ducks, sea birds, the occasional beluga whale and musk ox and scavenged whale and walrus carcasses.
Mitchell Taylor also testified to the FWS that a modest warming may be beneficial to bears. It creates a better habitat for seals and would dramatically increase the growth of blueberries on which the bears like to gorge.
Listing the polar bear as threatened could give the federal government enormous power to regulate economic activity in the country. In effect, the Endangered Species Act would become a vehicle for implementing limits on greenhouse gas emissions—and Congress wouldn’t even have to pass new legislation.
See Polar Bears on Thin Ice, Not Really! Redux by H. Sterling Burnett, National Center for Policy Analysis, February 21, 2008; and Don’t List the Polar Bear Under the Endangered Species Act by Ben Lieberman, The Heritage Foundation, January 25, 2008.