Global warming may make the Arctic of today a thing of the past

Washington, September 11 (ANI): If a new research is anything to go by, then the Arctic as we know it may soon be a thing of the past, with global warming causing dramatic biological responses in the region.

The research was led by Eric Post, associate professor of biology at Penn State University, along with 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 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," said 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," he added.

The study 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.

The research also reveals that species once confined to more southerly ranges now are moving northward.

Among the most visible invaders are red foxes, which are displacing Arctic foxes from territories once too cold for red foxes.

Some of the less showy invaders that the scientists found also are moving northward include the winter moth, which defoliates mountain birch forests, and species of Low Arctic trees and shrubs, which affect the dynamics of trace-gas exchange.

Post's research team shows that the effects of Arctic warming have been dramatic so far, especially since the warming amounts to only about 1-degree Celsius over the last 150 years.

"The results of our studies so far reveal widespread changes, but also a surprising heterogeneity in biological responses to warming," said Post. (ANI)