"Cold and snowy winters will be the rule, rather than the exception," says Dr James Overland of the NOAA/Pacific Marine Environmental Laboratory in the United States. Dr Overland is at the International Polar Year Oslo Science Conference (IPY-OSC) to chair a session on polar climate feedbacks, amplification and teleconnections, including impacts on mid-latitudes.

Loss of sea ice causes major climate change

Continued rapid loss of sea ice will be an important driver of major change in the world's climate system in the years to come.

"While the emerging impact of greenhouse gases is an important factor in the changing Arctic, what was not fully recognised 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 working together has disrupted the memory and stability of the Arctic climate system, resulting in greater ice loss than earlier climate models predicted," says Dr Overland.

"The exceptional cold and snowy winter of 2009-2010 in Europe, eastern Asia and eastern North America is connected to unique physical processes in the Arctic," he says.

Irreversible change

The Arctic is warming more than twice as fast as the rest of the planet. This is known as Arctic amplification -- a much debated phenomenon at the IPY-OSC, where 2400 polar scientists have gathered to discuss the huge amount of research and new findings which are the direct result of the International Polar Year.

The changes are happening a great deal faster than the scientific community expected. Given the recent reduction of the area of multi-year sea ice and reduced ice thickness, it is unlikely that the Arctic can return to its previous condition.

"The changes are irreversible," says Dr Overland.

A landmark event

"The IPY Oslo Science Conference is a landmark event in our understanding of the Arctic climate," says Dr Overland, who is chairing one of the sessions on climate at the conference. More than 80 scientific papers have been submitted discussing Arctic amplification and its impacts.