Wildlife biologists and climate scientists overwhelmingly agree that the disappearance of Arctic sea ice will lead to a sharp drop in polar bear populations. But some sceptics remain unconvinced, and they have managed to persuade the Canadian government not to take key steps to protect the animals.
In the spring of 2008, US Interior Secretary Dirk Kempthorne - an appointee of President George W. Bush - held a conference call with a blue-ribbon panel of scientists to discuss whether polar bears should be placed on the endangered species list. Given the Bush administration’s environmental record, many of the 19 scientists were apprehensive about how Kempthorne was going to respond to their report, which warned that projected climatic changes in the Arctic would lead to the probable elimination of two-thirds of the world’s 20,000 to 25,000 polar bears in much of their range within 45 years.
Kempthorne said he had given serious consideration to the studies by US and Canadian experts that led them to support listing polar bears under the Endangered Species Act. He then thanked them for their work and said he could find no flaw in any of the nine studies they had conducted to come to their conclusion.
“My hope is that the projections from these models are wrong, and that sea ice does not recede further,” Kempthorne said a few days later in announcing his decision to list the polar bears as a “threatened” species. “But the best science available to me currently says that this is not likely to happen in the next 45 years.”
If ever a set of facts - and a government action - underscored the impact of global warming, this was it. But in the months since Kempthorne’s decision, global warming sceptics have insisted that the climate change models used by the panel of experts were wrong, that polar bears have survived warming in the past, and that the species can adapt to a life on land by eating goose eggs and berries.
The war of scientific words over the future of the polar bear has not just taken place on fringe web sites, but has spilled into the pages of The New York Times, the UK’s Daily Telegraph, and several scientific journals. And though the arguments of global warming sceptics have been widely discredited, they seem to have created enough of a grey area to provide cover for the Canadian government not to initiate management plans that might help some polar bear populations weather the warming that is destroying their icy habitat.
One reason the polar bear has become such a passionate topic of debate is its power as a symbol of climate change, with one sceptic lamenting that the bears have become the “poster-series for doomsday prophets of global catastrophe from anthropogenic climate change”.
But the polar bear image has power for a reason: Arctic sea ice is rapidly shrinking. Polar bears are being adversely affected as the key element in their habitat - ice - disappears. And unlike models and projections of future climate disruption, these changes are happening now - swiftly and dramatically.
The debate over whether the polar bear is truly in trouble vividly highlights the assault that global warming sceptics often make on mainstream science, with a disparate band of dissenters - many of them weighing in on issues in which they have little expertise - challenging the extensive research of a wide array of scientists. Among those offering dissenting views on polar bears and climate change are a marketing professor from the University of Pennsylvania, a graduate student in ornithology from the City University of New York, and a fisheries scientist. Other entities such as the Safari Club, an organisation representing big-game hunters, and the Alaska state government, under Governor Sarah Palin, have also tried to discredit the science underlying Kempthorne’s decision.
These groups and individuals have taken on members of the blue-ribbon advisory panel, including polar bear biologists and climate experts from the US Geological Survey, the US Fish and Wildlife Service, the Woods Hole Oceanographic Institute, the Canadian Wildlife Service, the Wildlife Conservation Society, and several American universities.
“It has been frustrating,” acknowledges Ian Stirling, a Canadian Wildlife Service scientist who has worked on polar bears for more than 35 years. “But nothing that has been said or written changes anything. The science here is as solid as it can be.”
The science is straightforward. As greenhouse gas concentrations in the atmosphere rapidly increase, the Arctic is warming significantly. Satellite images show that the extent of Arctic summer sea ice has decreased by roughly 30 per cent since 1979, reaching a historic low two years ago. Thicker, multi-year sea ice also is disappearing.
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