Blue Planet News

By Lisa Raffensperger on Monday, October 22, 2007.

(c) http://earthtrends.wri.org/updates/node/250

If greenhouse gas emissions continue in the “business as usual” trend, two-thirds of the world’s polar bears may become extinct by 2050, according to a study released last month by the U.S. Geological Survey. The series of nine reports prepared by the USGS are intended to aid the U.S. Fish and Wildlife Service’s upcoming decision on whether to designate the polar bear threatened under the Endangered Species Act. The period of public comments on these reports, which ended today, was the final period of public input before the January 9, 2008 final listing determination.
The listing process has been closely watched by many environmental groups since its beginning in February 2005 for its importance not only in determining the fate of the polar bear species, but also its far-reaching potential to force U.S. action to curb greenhouse gas emissions. If the polar bear is listed, all federal agencies will be prohibited from taking any action that will be likely to jeopardize the bear’s continued existence or adversely modify its critical habitat. This could potentially include permits for resource extraction, power-plant operation, and shipping routes through the Arctic.
Without action soon to reduce greenhouse gases, especially ones that disproportionately warm polar regions, polar bears could very possibly become the first mammals to lose 100 percent of their habitat by global warming.
Sea Ice Loss Accelerating

Polar bears depend upon sea ice from which to hunt seals, their primary prey. The extent of Arctic sea ice varies from year to year, but this summer saw the most drastic melting yet on record, according to the National Snow and Ice Data Center. Measurements in September 2007 shattered the previous low, set in September 2005, by 23 percent. Arctic sea ice receded so much, in fact, that the well-known Northwest Passage became completely opened for the first time in human memory. The NSIDC scientists agree that the Arctic Ocean may be completely ice-free in the summer by 2030, a phenomenon that hasn’t happened in the last million years.
Even in the case of only partial melting, the Center for Biological Diversity says, polar bears will experience “shortening of the hunting season caused by delayed ice formation and earlier ice break-up, resulting in reduced fat stores, deteriorated body condition, and subsequent reduced survival and reproduction” (CBD, 2007).

Source: NSIDC, 2007 This image compares the average sea ice extent for September 2007 (on LEFT) to September 2005; the magenta line indicates the long-term median from 1979 to 2000.
What Can Be Done Right Now

While bills now being debated by Congress focus on CO₂ reductions, non-CO₂ greenhouse gases are at the center of a recent appeal by environmental group Center for Biological Diversity to save polar bears and their Arctic habitat. Last week the group introduced their “Rapid Action Plan” at a hearing of the House Committee on Science and Technology, outlining the most pressing steps that must be taken to slow Arctic melting. Though any long-term approach to global climate change must necessarily address CO₂, the plan’s authors emphasized short-term reduction of non-CO₂ pollutants, including methane and black carbon, or soot. These pollutants disproportionately affect the Arctic, accounting for at least half of warming there, compared to their estimated 30 percent contribution worldwide. In addition, both methane and black carbon have a much shorter atmospheric lifetime than CO₂