A recent Arctic climate study confirms what scientists have been saying for years - glaciers are melting at an alarming rate and ocean levels are up, writes Dick Ahlstrom.
Santa may have to move his headquarters from the North Pole if global warming continues at its current rapid rate. Researchers have confirmed that climate is changing at an accelerated pace in the Arctic region.
Temperatures have risen at nearly twice the rate of the rest of the world over the past two decades. Sea ice cover is shrinking, with continued lost ice and earlier spring break-up of ice in rivers and estuaries.
How quickly things are changing in the region and the likely consequences were discussed in the Arctic Climate Impact Assessment, a four-year Arctic climate study. It was backed by the Arctic Council, an intergovernmental forum with eight Arctic country members and six indigenous peoples' organisations, and the International Arctic Science Committee, a grouping of 18 national academies of science.
The "overwhelming volume of scientific data in the report presents unmistakable trends" that back up decades of anecdotal evidence coming from those living in the region, the report indicates.
Mean annual surface air temperature over the past 50 years has increased by 3 to 4 degrees in Alaska and Siberia. Sea ice cover in late summer decreased by 15 to 20 per cent over the past 30 years. North American glaciers lost 174 cubic kilometres of ice between 1961 and 1998, enough to cover all of Ireland in a layer of water more than 5.3 metres deep.
Local plants and animals are also affected. White spruce - the most valuable timber species in the North American boreal forest - experienced sharp declines as summer temperatures exceeded the tree's upper limits. Seal pups were non-existent in Canada's Gulf of St Lawrence during the ice-free years of 1967, 1981, 2000, 2001 and 2002.
Projected future trends provide cold comfort but not the kind of cold needed. The average summer sea ice extent is projected to fall by 50 per cent by 2100. The report estimates mean annual surface air temperatures over the region north of 60 degrees latitude will rise by 4 to 7 degrees by the end of this century. This is expected to be enough to initiate long-term melting of the vast Greenland ice sheet, a massive body of ice that will raise ocean levels as it goes.
Arctic glaciers hold a spectacular 3.1 million cubic kilometres of ice, more than the entire volume of sea water that makes up the Gulf of Mexico. The researchers estimate that Arctic ice-melt will raise sea level by about 2.5 centimetres over the next 60 years. The figure will stand at 7.5 centimetres by the end of this century if current trends continue.
If the entire Greenland ice sheet were to melt, maps around the world would have to be rewritten. These sheets contain enough water to lift sea level by seven metres.
The less harsh conditions over land as things warm up will encourage the northwards march of vegetation - forests that will begin to colonise former tundra. "Although forest growth increases carbon dioxide uptake, this beneficial effect will be overwhelmed by the release of large stores of methane and carbon dioxide as tundra regions thaw," the report indicates.
The increased absorption of solar radiation by forests, compared with the more reflective tundra they will replace, will also lead to net warming in these regions.
Cold-loving species will struggle to survive. Polar bears will be pushed to extinction given an end of their life on the ice. Ringed seals are entirely dependent on sea ice for their survival and will be the most vulnerable species if the ice goes.
It will also mean disaster for indigenous cultures in the polar region. Caribou and reindeer depend on tundra vegetation. How will these peoples cope with the loss of traditional food sources? Is it too late to stop these changes from coming to pass or is the meltdown of the Arctic inevitable?