Polar bears are under threat of starvation from climate change due to melting sea ice, a new study from scientists with the Canadian Wildlife Service concludes. The study, by Canadian polar bear scientists Ian Stirling, Nicholas J. Lunn and John Iacozza, found that the bears' main food source, ringed seals which live on the ice of Hudson Bay, are becoming less accessible because of a shorter ice season.
"We're wrong if we think that climate change is something that will happen far off in the future. Polar bears are starving now and we need to act now to stop climate change," said Kevin Jardine, Greenpeace climate impacts specialist.
Building on a past NASA study which found a 2.9 percent decline per decade in total Arctic sea ice extent over the last 20 years, the new Canadian study further concludes that the sea ice season in western Hudson Bay has been reduced by about three weeks over the same period.
The study says that, as a result of the reduction in sea ice, polar bears have less time to hunt and are returning to land in poorer condition. Weight for both male and female polar bears is declining and female bears are having fewer cubs. Although significant population decline has not yet begun, this is inevitable if the trends continue.
Hudson Bay polar bears are unique in the Arctic because of their tendency to fast for six to eight months each year, depending heavily on hunting during the sea ice season for survival. Since the sea ice season is the shortest in Hudson Bay of all the regions of the Arctic Ocean, these bears are on the edge of survival, and are likely to be among the first to be affected by sea ice decline. The Canadian study also draws attention to an increase in bear-human altercations as hungry polar bears wander into the northern Canadian community of Churchill, Manitoba.
Executive Director of the Churchill Northern Study Center, Harvey Lemelin, said:
"What we consider encounters now are not only bear sightings but bears that have to be moved away from the property using everything from dogs to vehicles to cracker shells. From the last three years we've gone from 20 encounters to 36 and we're not done with the season yet."
"Starving polar bears, Asian floods and dying coral reefs are all major climate danger signals," said Jardine. "World governments must begin urgent negotiations to cut global greenhouse gas emissions by more than 50 percent and begin the phase-out of fossil fuels such as coal, oil and natural gas," he said.