Changes

[[Image:Polar_bears.jpg|left|thumb|200px|A mother polar bear and her two cubs]]

[[Image:Polar_bears.jpg|left|thumb|200px|A mother polar bear and her two cubs]]

The polar bear is on the [[Endangered Species List]] in the [[United States]]. The current world population is estimated at around 22-27,000, around twice what it was in the 1960s.<ref>http://www.naturecanada.ca/climate_change_polar.asp</ref>

The current world population is estimated at around 22-27,000, around twice what it was in the 1960s.<ref>http://www.naturecanada.ca/climate_change_polar.asp</ref> Nonetheless, environmentalists got the polar bear placed on the [[Endangered Species List]] "to force the U.S. government to take action on [[global warming]]. <ref>The aim of the environmentalists is to use the Endangered Species Act to force the U.S. government to take action on global warming, said Kassie Siegel, a lawyer for the [[Center for Biological Diversity]]. It would require federal agencies "to look at the cumulative effect of greenhouse gases on polar bears" and limit emissions by cars and power plants, Siegel said. [http://www.usatoday.com/weather/climate/globalwarming/2008-03-09-polar-bears_N.htm] </ref>]

Polar bears have been known to [[interbreed]] with [[grizzly bear]]s in the wild, producing a polar-grizzly hybrid.<ref>http://www.msnbc.msn.com/id/12738644/GT1/8199/</ref>

Polar bears have been known to [[interbreed]] with [[grizzly bear]]s in the wild, producing a polar-grizzly hybrid.<ref>http://www.msnbc.msn.com/id/12738644/GT1/8199/</ref>

{{main|Global warming controversy}}

{{main|Global warming controversy}}

[[Image:Polar bear trends.jpg|right|thumb|Population shows an increasing trend]]Activists from the  [[Center for Biological Diversity]] claim that "... the primary threat to polar bears is global warming",<ref>[http://www.iht.com/articles/2006/12/28/news/bear.php Melting arctic ice pushes polar bear population closer to the edge: Activists see animal as a global symbol], ''International Herald-Tribune''</ref> although scientists assert that the polar bear population is stable<ref>The IUCN Polar Bear Specialist Group ... reported that of the 19 subpopulations of polar bears, five are declining, five are stable, two are increasing, and seven have insufficient data on which to base a decision. [http://www.polarbearsinternational.org/bear-facts/ Bear Facts] </ref> or increasing.<ref>"There aren't just a few more bears. There are a hell of a lot more bears," said Mitch Taylor, a polar bear biologist who has spent 20 years studying the animals. [http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/03/09/wpolar09.xml Polar bears 'thriving as the Arctic warms up'] </ref>

[[Image:Polar bear trends.jpg|right|thumb|Population shows an increasing trend]]Activists from the  [[Center for Biological Diversity]] claim that "... the primary threat to polar bears is global warming",<ref>[http://www.iht.com/articles/2006/12/28/news/bear.php Melting arctic ice pushes polar bear population closer to the edge: Activists see animal as a global symbol], ''International Herald-Tribune''</ref> although scientists assert that the polar bear population is stable<ref>The IUCN Polar Bear Specialist Group ... reported that of the 19 subpopulations of polar bears, five are declining, five are stable, two are increasing, and seven have insufficient data on which to base a decision. [http://www.polarbearsinternational.org/bear-facts/ Bear Facts] </ref> or increasing.<ref>"There aren't just a few more bears. There are a hell of a lot more bears," said Mitch Taylor, a polar bear biologist who has spent 20 years studying the animals. [http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/03/09/wpolar09.xml Polar bears 'thriving as the Arctic warms up' (Polar Bears Caught in a Heated Debate] - ''USA Today''</ref>

==References==  

==References==