Arctic thaw threatens people, polar bears

Global warming is heating the Arctic almost twice as fast as the rest of the planet in a thaw that threatens millions of livelihoods and could wipe out polar bears by 2100, an eight-nation report said yesterday.

The biggest survey to date of the Arctic climate, by 250 scientists, said the accelerating melt could be a foretaste of wider disruptions from a build-up of human emissions of heat-trapping gases in the earth's atmosphere.

The "Arctic climate is now warming rapidly and much larger changes are projected," according to the Arctic Climate Impact Assessment (ACIA), funded by the United States, Canada, Russia, Denmark, Iceland, Sweden, Norway and Finland.

Arctic temperatures are rising at almost twice the global average and could leap 4-7 Celsius by 2100, roughly twice the global average projected by UN reports. Siberia and Alaska have already warmed by 2-3 C since the 1950s.

Possible benefits like more productive fisheries, easier access to oil and gas deposits or trans-Arctic shipping routes would be outweighed by threats to indigenous peoples and the habitats of animals and plants.

Sea ice around the North Pole, for instance, could almost disappear in summer by the end of the century. The extent of the ice has already shrunk by 15-20 per cent in the past 30 years.

"Polar bears are unlikely to survive as a species if there is an almost complete loss of summer sea-ice cover," the report said. On land, creatures like lemmings, caribou, reindeer and snowy owls are being squeezed north into a narrower range.

The report mainly blames the melt on gases from fossil fuels burnt in cars, factories and power plants. The Arctic warms faster than the global average because dark ground and water, once exposed, traps more heat than reflective snow and ice.

Klaus Toepfer, head of the UN Environment Programme, said the Arctic changes were an early warning. "What happens there is of concern for everyone because Arctic warming and its consequences have worldwide implications," he said.

And the melting of glaciers is expected to raise world sea levels by about ten centimetres by the end of the century.

Many of the four million people in the Arctic are already suffering. Buildings from Russia to Canada have collapsed because of subsidence linked to thawing permafrost that also destabilises oil pipelines, roads and airports.