As an Alaskan wildlife biologist with much polar bear experience, I disagree with Gov. Sarah Palin about the effects of global warming on polar bears.
In a letter to Interior Secretary Kempthorne on Oct. 22, 2007, Palin stated that listing of polar bears as threatened under the Endangered Species Act was based entirely on highly speculative and uncertain climate and ice modeling. This is not correct. Studies for listing were based on conservative projections of sea ice loss and related information from the Intergovernmental Panel on Climate Change, the world leader in gathering, analyzing, and reporting on global warming.
The U.S. Marine Mammal Commission stated that modeling used to predict reductions in sea ice and its effect on polar bears constitutes the best scientific information available. Recent studies by the National Oceanic and Atmospheric Administration indicate that sea ice loss is occurring at a greater rate than predicted by the conservative models used for the polar bear listing.
Palin has downplayed the significance of human activities as a cause of global warming and climate change. This is in contrast to the IPCC, which concluded in 2007 that the odds were better than 90 percent that humans were to blame for the current warming.
Palin in an opinion piece (Anchorage Daily News, Dec. 18, 2007) stated that Alaska's Beaufort Sea polar bear population has been stable for 20 years. The condition of bears, cub recruitment, and demographic trends of this population are all declining as sea ice decreases. Other signs of population instability include a shift toward land-based denning, abandonment of areas with high rates of ice degradation, and starved and cannibalized bears.
Andrew Derocher, a preeminent Canadian polar bear biologist and chairman of the international Polar Bear Specialist Group, said there is very clear consensus that the Beaufort Sea population is not doing well, and that polar bear scientists without exception are concerned about the long-term preservation of the species.
Palin has implied that the state of Alaska has an active polar bear program, has enacted a ban on most hunting of bears, and participates internationally to conserve polar bears worldwide. In fact, the state has not had a polar bear program since the Marine Mammal Protection Act of 1972 transferred management authority from the state to the federal government. The only regulations for hunting are federal. The state is not a party to international polar bear agreements and is not represented on the international Polar Bear Specialist Group.
In opinion pieces (Anchorage Daily News, Dec. 18, 2007; New York Times, Jan. 5, 2008), Palin stated that her opposition to listing under the Endangered Species Act is based on comprehensive review by state wildlife officials of scientific information from a broad range of climate, ice, and polar bear experts. This is highly misleading.
The vast majority of climate, ice and polar bear experts agree that the projections, analyses and predictions on which the listing is based are valid. These include the director of Palin's own Fish and Game Department marine mammal program and two state biologists with Arctic and marine mammal experience, who agree that methods and analytical approaches used to examine the currently available information justify a threatened species listing for polar bears.
The Division of Wildlife Conservation in the Alaska Department of Fish and Game stated that information on sea ice loss in the current scientific literature represents the best available science, and if ice loss projections are accurate the polar bear will decline significantly across much of its range.
Along with her non-acceptance of the effects of global warming and climate change on polar bears, Palin believes they should not be listed as threatened because this could slow or block development. As vice-president she would be widely recognized as an Alaskan expert and have considerable influence on how the Endangered Species Act was interpreted and how much protection was extended to polar bears.
Jack Lentfer, an Alaskan wildlife biologist, has worked for the Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service. He has served on the international Polar Bear Specialist Group, U.S. Marine Mammal Commission, and the Alaska Board of Game. He lives in Homer.