10年后 北极夏天或成"无冰世界"

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The results of a new Arctic survey shows that North Pole ice is melting faster than previously projected and scientists at Cambridge University predict the Arctic ocean will be largely ice-free during the summer within the next ten years. The findings are expected to add to the debate at the Copenhagen climate conference in December.

Earlier this year, British explorer Pen Hadow and his team trekked for three months across the frozen Arctic Ocean, taking measurements and recording observations about the ice.

"We'd been led to believe that we would encounter a good proportion, of this older, thicker, technically multi-year ice that's been around for a few years and just gets thicker and thicker," he said. "We actually found there wasn't any multi-year ice at all."

Satellite observation and submarine surveys over the past few years had shown less ice in the polar region, but the recent measurements show the loss is more pronounced than previously thought.

"We're looking at 80 percent roughly loss of ice cover on the Arctic Ocean in 10 years, and 100 percent loss in nearer 20 years," said Hadow.

Cambridge scientist Peter Wadhams, who's been measuring and monitoring the Arctic since 1971 says the decline is irreversible.

"The more you lose, the more open water is created, the more warming goes on in that open water during the summer, the less ice forms in the winter, the more melt there is the following summer," he said. "It becomes a breakdown process where everything ends up accelerating until it's all gone."
 
Martin Sommerkorn runs the Arctic program for the environmental charity the World Wildlife Fund.

"The Arctic sea ice holds a central position in the Earth's climate system and it's deteriorating faster than expected," he said. "Actually directly has to translate into more urgency to deal with the climate change problem and reduce emissions."

Summerkorn says a plan to reduce greenhouse gas emissions blamed for global warming needs to come out of the Copenhagen Climate change summit in December.

"We have to basically achieve there the commitment to deal with the problem now," he said. "That's the minimum. We have to do that equitably and we have to find a commitment that is quick."  

Wadhams echoes the need for urgency.

"The carbon that we've put into the atmosphere keeps having a warming effect for 100 years, so we have to cut back rapidly now, because it will take a long time, there's a flywheel effect, it will take a long time to work its way through into a response by the atmosphere. We can't switch off global warming by being good in the future, we have to start being good now," he said.

Wadhams says there is no easy techno-fix to climate change. He and other scientists say there are basically two options to replacing fossil fuels, generate energy with renewables, or embrace nuclear power.