If you are daunted by the threat of climate change, the latest research from the Arctic could help you cast off your despondency and gain some optimism. That’s because we can avoid wiping out the ice cap and the polar bears that live there, US scientists have shown this week. In particular University of Washington professor Cecilia Bitz and colleagues found no “tipping point” of greenhouse gas-driven warming beyond which summer sea ice loss is unstoppable. “Our research offers a very promising, hopeful message, but it’s also an incentive for mitigating greenhouse emissions,” Bitz said.
Polar bears need sea ice because it lets them get to their primary food sources, ringed and bearded seals. When they can’t access sea ice, they therefore mostly go without food and can lose about 2 pounds in weight a day. The length of these periods without access has increased and will continue increasing with the current level of greenhouse gas emissions. Researchers from the US Geological Survey (USGS) had previously used climate models to predict that sea-ice loss will mean that only about one-third of the world’s 22,000 polar bears might be left by mid-century. That work went on to say that eventually polar bears could disappear completely, leading to their listing as a threatened species in 2008. Read the rest of this entry »