Keep in mind that the decline isn't actually occurring right now. The movement to get the polar bear listed as threatened is based on what-if computer scenarios.

But what if the assumptions are wrong, and the projected warming does not occur? No matter. Once the polar bear is listed, environmental law can more easily be used as a bludgeon for The Cause. Just about any human activity can -- with appropriate logical gymnastics -- be tied to climate change, so pretty much no human activity in America would remain beyond the reach of the environmental regulators.