National Public Radio: The Endangered Species Act, which turns 40 on Saturday, helped bring back iconic species such as the wolf, grizzly bear and bald eagle, after hunting, trapping and pesticides almost wiped those animals out.
But a very different kind of threat - global warming - is pushing some species like the polar bear to the brink of extinction.
One government biologist discovered the best way he could help save polar bears was to quit his job.
A New Kind Of Conservation Problem
Several years ago,...