June 12, 2010
Expect More Cold, Snowy Winters: Expert
North America, Europe and eastern Asia could see more cold, moist and snowy winters much like the one that just passed, according to one top scientist.
James Overland of the US National Oceanic and Atmospheric Administration (NOAA) told the AFP news agency, "Cold and snowy winters will be the rule rather than the exception."
It may seem counter-intuitive, but warmer Arctic climates caused by climate change influence air pressure at the North Pole, which shifts wind patterns in such a way as to increase a cooling effect over adjacent regions of the planet.
Continued loss of ice will be an important driver of major change in the world's climate system in the coming years, said Overland at an Oslo meeting of scientists reviewing research from International Polar Year 2007-08.
The remarkably cold winter of 2009-10 in northern hemisphere temperate zones were connected to unique physical processes in the Arctic.
"The emerging impact of greenhouse gases in an important factor in the changing Arctic," Overland explained in a statement.
"What was not fully recognized until now is that a combination of an unusual warm period due to natural variability, loss of sea ice reflectivity, ocean heat storage, and changing wind patterns all working together to disrupt the memory and stability of the Arctic climate system," he said.
The region is warming more than two times faster than the rest of the planet -- a phenomenon known as Arctic amplification.
Earlier climate models failed to predict the resulting ice loss accurately. The polar ice cap shrank to its smallest surface area since records were first kept in 2007, and early data suggests it could become even smaller this summer.
"It is unlikely that the Arctic can return to its previous condition," Overland added. "The changes are irreversible."
On the Net: