With 20-25,000 polar bears living in the wild, the species is notcurrently endangered, but its future is far from certain. In 1973,Canada, the United States, Denmark, Norway and the former U.S.S.R.signed the International Agreement on the Conservation of Polar Bearsand their Habitat. This agreement restricts the hunting of polar bearsand directs each nation to protect their habitats, but it does notprotect the bears against the biggest man-made threat to theirsurvival: global warming. If current warming trends continue unabated,scientists believe that polar bears will be vulnerable to extinctionwithin the next century.