The Arctic: 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.
And a separate report sugested that North American wildlife species ranging from butterflies to red fox were scrambling to adapt to rising temperatures and might not survive.
According to the Pew Center on Global Climate Change, North American species like the Edith's Checkerspot butterfly, red fox and Mexican jay were moving to colder northern climates that suit their habits.
With global temperatures expected to rise another 2.5 degrees to 10.4 degrees Fahrenheit (about 1 degree to about 5 degrees Celsius) by 2100, "future global warming is likely to exceed the ability of many species to migrate or adjust," said the Pew Center, citing the evidence of 40 scientific studies.
The Edith's Checkerspot butterfly has disappeared from many southern, low-elevation areas like Mexico, fleeing to colder Canadian climes. The red fox has also moved northward to clash with Arctic fox populations, in a trend spotted in many other birds, mammals, invertebrates and plants, said Pew.
The largest Arctic survey to date, carried out by 250 scientists, said the accelerating polar icecap 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 degrees by 2100, roughly twice the global average projected by UN reports. Siberia and Alaska have already warmed by 2-3 degrees since the 1950s.
Possible benefits such as 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 such as 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.
Mr 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. The melting of glaciers is expected to raise world sea levels by about 10 cm (4 inches) 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. - (Reuters)