The polar bear has become the poster animal for the devastating changes global warming is bringing to the Arctic. Polar bears are dying because their range is shrinking; the sea ice they use to hunt seals is melting as temperatures rise. With a recognized 19 subpopulations in decline, the International Union for Conservation of Nature (IUCN) estimates that there fewer than 26,000 polar bears worldwide.
A new study paints an even more dire picture. Researchers led by Eric Regehr of the U.S. Fish and Wildlife Service in Anchorage, Alaska, combined 35 years of satellite data on Arctic sea ice with shifts in polar bears groupings across four Arctic zones. They found that there's a 70 percent chance the polar bear population will decline by more than 30 percent by the middle of this century.