Polar bears, the poster-species for climate change, have been the subject of reports about new or growing threats in 2010: One story noted that the warming Arctic is pushing grizzlies north into polar bear territory, while another questioned whether polar bears can change their diet as their icy habitat melts. But the journal Nature this week brought an antidote to all that doom and gloom. A study modeling the Arctic climate suggests that it's still not too late to protect the polar bear habitat, and therefore save the polar bear. The world just needs to reduce its greenhouse gas emissions. The question is one of tipping points: Is the total demise of the Arctic summer sea ice already inevitable, or could a slowing of emissions also slow down the ice loss?
The dramatic retreat of Arctic sea ice in the summer of2007 prompted some researchers to warn that the system may have reached a tipping point that would lead to the disappearance of summer sea ice within the next several decades, regardless of actions humans took to reduce greenhouse-gas emissions. That concern, in turn, helped elevate the polar bear to climate-icon status and reportedly fed into then-President George W. Bush's decision in 2008 to list the bear as "threatened" under the Endangered Species Act. The new study, however, finds no "tipping point" now or in this century in Arctic sea-ice decline, but rather a relatively steady fall-off in ice extent as average temperatures increase. [Christian Science Monitor]
