"We are concerned," said Mr. Kempthorne, that "the polar bears' habitat may literally be melting" due to warmer Arctic temperatures. However, when we called Interior spokesman Hugh Vickery for some elaboration, he was a lot less categorical, even a tad defensive. The "endangered" designation is based less on the actual number of bears in Alaska than on "projections into the future," Mr. Vickery said, adding that these "projection models" are "tricky business." 

Apparently so, because there are in fact more polar bears in the world now than there were 40 years ago, as the nearby chart shows. The main threat to polar bears in recent decades has been from hunting, with estimates as low as 5,000 to 10,000 bears in the 1950s and 1960s. But thanks to conservation efforts, and some cross-border cooperation among the U.S., Canada and Russia , the best estimate today is that the polar bear population is 20,000 to 25,000. 

It also turns out that most of the alarm over the polar bear's future stems from a single, peer-reviewed study, which found that the bear population had declined by some 250, or 25%, in Western Hudson Bay in the last decade. But the polar bear's range is far more extensive than Hudson Bay . A 2002 U.S. Geological Survey of wildlife in the Arctic Refuge Coastal Plain concluded that the ice bear populations "may now be near historic highs." One of the leading experts on the polar bear, Mitchell Taylor, the manager of wildlife resources for the Nunavut territory in Canada , has found that the Canadian polar bear population has actually increased by 25% -- to 15,000 from 12,000 over the past decade.

Mr. Taylor tells us that in many parts of Canada , "polar bears are very abundant and productive. In some areas, they are overly abundant. I understand that people not living in the North generally have difficulty grasping the concept of too many polar bears, but those who live here have a pretty good grasp of what that is like." Those cuddly white bears are the Earth's largest land carnivores. 

There is no doubt that higher temperatures threaten polar bear habitat by melting sea ice. Mr. Kempthorne also says he had little choice because the threshold for triggering a study under the Endangered Species Act is low. The Bush Administration was sued by the usual environmental suspects to make this decision, which means that Interior will now conduct a year-long review before any formal listing decision is made. 

Nonetheless, the bears seem to have survived despite many other severe warming and cooling periods over the last few thousands of years. Polar bears are also protected from poaching and environmental damage by the Marine Mammal Protection Act, so there is little extra advantage to the bears themselves from an "endangered" classification. 

All of which suggests that the real story here is a human one, namely about the politics of global warming. Once a plant or animal is listed under the Endangered Species Act, the government must also come up with an elaborate plan to protect its habitat. If the polar bear is endangered by warmer temperatures, then the environmentalist demand will be that the government do something to address that climate change. Faster than you can say Al Gore, this would lead to lawsuits and cries in Congress demanding federal mandates to reduce greenhouse gas emissions. 

Think we're exaggerating? No sooner had Mr. Kempthorne announced his study than Kassie Siegel of something called the Center for Biological Diversity told the New York Times that "even this Administration" would not be able to "write this proposal without acknowledging that the primary threat to polar bears is global warming and without acknowledging the science of global warming." Her outfit was one of those who had sued the feds in the first place over the polar bears, notwithstanding its location in the frozen tundra of Arizona . But no matter. For want of a few hundred polar bears, the entire U.S. economy could be vulnerable to judicial dictation. 

With that much at stake, Mr. Kempthorne could have shown a stiffer backbone in resisting this political pressure. At the very least he now has an obligation to ensure that Interior's year-long study be based on real science and the actual polar bear population, rather than rely on computer projections. Any government decision to limit greenhouse gases deserves to be debated in the open, where the public can understand the consequences, not legislated by the back door via the Endangered Species Act. 

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