Dramatic biological responses to global warming in the Arctic

“The Arctic as we know it may soon be a thing of the past,” says Eric Post, associate professor of biology at Penn State University. Post leads a large, international team that carried out ecosystem-wide studies of the biological response to Arctic warming during the fourth International Polar Year, which ended in 2008. The team’s results will be reported on 11 September 2009 in the journal Science.

The team’s research documents a wide range of responses by plants, birds, animals, insects, and humans to the warming trend. The scientists found that the increase in mean annual surface temperature in the Arctic over the last 150 years has had dramatic effects. In the last 20 to 30 years, for example, the seasonal minimal sea ice coverage has declined by a staggering 45,000 square kilometers per year. Similarly, the extent of terrestrial snow cover has declined steadily, with earlier melting and breaking up and an earlier start to the growing season. “Species on land and at sea are suffering adverse consequences of human behavior at latitudes thousands of miles away,” declares Post. “It seems no matter where you look — on the ground, in the air, or in the water — we’re seeing signs of rapid change.”

The study led by Post shows that many iconic Arctic species that are dependent upon the stability and persistence of sea ice are faring especially badly. Loss of polar ice habitat is causing a rapid decline in the numbers of ivory gull, Pacific walrus, ringed seal, hooded seal, narwhal, and polar bear. The researchers found that Polar bears and ringed seals, both of which give birth in lairs or caves under the snow, lose many newborn pups when the lairs collapse in unusually early spring rains. These species may be headed for extinction.

EurekAlert