Global warming could cause polar bears to go extinct by the end of the century by eroding the sea ice that sustains them, according to the most comprehensive international assessment ever done of Arctic climate change.
Current estimates place the global polar bear population at between 20,000 and 25,000, but warming temperatures have been melting Arctic sea ice at an alarming rate, depriving the polar bears of their natural habitat and making it harder for them to find food. In spring 2006, scientists found the bodies of several polar bears that had starved to death. Reduced food availability due to global warming has also resulted in polar bear cannibalism off the north coast of Alaska and Canada.
Some polar bears have drowned while attempting to swim to safety after being trapped on small islands of melting ice. The U.S. Minerals Management Service documented the drowning of at least four polar bears in September 2004, when the sea ice retreated a record 160 miles off the northern coast.
