The polar bear, an almost mythic animal in the minds of most Americans, has been thrust into a new role: poster child of those advocating action against global warming. The U.S. Department of the Interior earlier this month made the bear even more politically notorious by listing it as a threatened species under the Endangered Species Act. This move was based on data showing that due to global warming, the bear's arctic ice habitat is shrinking, and the species could become extinct in under 50 years.
The listing was not based on population data, a fact immediately noted by those who oppose global warming legislation. In fact, the data we have show that the bear's numbers seem to have increased over the last several decades.
There are a number of problems with concluding that the population is safe now based on the numbers. First, the population estimates from before the 1970s were nothing but guesses based on anecdotes. Second, polar bears were widely hunted and trapped until the International Agreement on the Conservation of Polar Bears was signed in 1973. Population increases due to removal of an introduced predator (humans) naturally followed.
(The graphic at right shows the polar bear's projected range. Habitat losses are in red and habitat gains are in blue.)
The new listing of polar bears as "threatened" is based not on population trends, but on the logical conclusion that if the species' habitat disappears, so will the bears. The belief that the icy habitat is in danger, in turn, came from the UN's Intergovernmental Panel on Climate Change. I leave readers to draw their own conclusions as to the reliability of this source.
At any rate, the new listing appears to be merely symbolic. Unlike a typical threatened species' habitat, which can be actively protected, melting sea ice due to worldwide climate change cannot be addressed by the simple restrictions available to the Endangered Species Act.
What is your opinion -- should polar bears be listed as threatened under the Endangered Species Act? Why or why not?