The National Snow and Ice Data Center in Boulder, Colo., said there was 5.65 million square miles of sea ice this winter, nearly 8 percent less than the average of 6.12 million square miles recorded from 1979 to 2000, the Anchorage Daily News reported Tuesday.
Steven Amstrup of the non-profit Polar Bears International said 2010 was one of the warmest years on record and last autumn's ocean circulation patterns led to late and weak ice formation throughout much of the arctic.
"Because polar bears depend on the surface of the sea ice to catch seals, those things are not favorable for polar bear survival," Amstrup said. "So, if you are a polar bear, this could be a tough year -- with increased starvation especially among the young and very old."
Amstrup said he is less concerned with what happens in 2011 or any individual year than he is with rising average temperatures in the arctic.
"If we are lucky, we will have a series of cold years with circulation patterns that conserve sea ice. Ultimately, however, the greenhouse gases signal will clearly emerge," he said.
"After that, all of the years will be bad for polar bears ... and polar bears ultimately will disappear."