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OXFORD, England: A rise of at least two metres in the world's sea levels is now almost unstoppable, experts told a climate conference at Oxford University on Tuesday.
"The crux of the sea level issue is that it starts very slowly but once it gets going it is practically unstoppable," said Stefan Rahmstorf, a scientist at Germany's Potsdam Institute and a widely recognised sea level expert. 乐外网资源，转载请表明来源 乐外网资源，转载请表明来源 An iceberg sculpted by the sea is seen in a bay beside the British Antarctic Survey's Rothera base January 23, 2009. [Agencies] 乐外网leWai.com "There is no way I can see to stop this rise, even if we have gone to zero emissions." 乐外网为您提供最优的考试服务 Rahmstorf said the best outcome was that after temperatures stabilised, sea levels would only rise at a steady rate "for centuries to come", and not accelerate. http://www.lewai.com乐外网 Most scientists expect at least 2 degrees Celsius warming as a result of man-made greenhouse gas emissions, and probably more. The world warmed 0.7-0.8 degrees last century. 本文来源于乐外网www.lewai.com Rahmstorf estimated that if the world limited warming to 1.5 degrees then it would still see two metres sea level rise over centuries, which would see some island nations disappear. CopyRight LeWai.com His best guess was a one metre rise this century, assuming three degrees warming, and up to five metres over the next 300 years. 乐外网资源，转载请表明来源
"There is nothing we can do to stop this unless we manage to cool the planet. That would require extracting the carbon dioxide from the atmosphere. There is no way of doing this on the sufficient scale known today," he said. CopyRight LeWai.com Scientists say that ice melt acquires a momentum of its own - for example warming the air as less ice reflects less heat, warming the local area. 本文来源于乐外网www.lewai.com "Once the ice is on the move, it's like a tipping point which reinforces itself," said Wageningen University's Pier Vellinga, citing various research. 乐外网，学习考试培训网 "Even if you reduce all the emissions in the world once this has started it may be unstoppable. I conclude that beyond 2 degrees global average temperature rise the probability of the Greenland ice sheet disintegrating is 50 percent or more." 乐外网为您提供最优的考试服务 "(That) will result in about 7 metres sea level rise, and the time frame is about 300-1,000 years." http://www.lewai.com乐外网 STORM 乐外网leWai.com Delegates from about 190 nations are meeting in Bangkok to try to speed up UN-led negotiations to replace the Kyoto Protocol with a tougher climate pact. 乐外网leWai.com Speakers in Oxford used history to back up their arguments on rising seas. Three million years ago the planet was 2-3 degrees warmer and the sea 25-35 metres higher, and 122,000 years ago 2 degrees warmer and 10 metres higher, they said. 乐外网，学习考试培训网 "What we now see in Greenland, Antarctica could be a temporary phenomena but it could also be the start of what we saw 122,000 years ago," said Vellinga. 内容来自乐外网 Sea levels have risen about 20 centimetres in the past century and that effect was accelerating, speakers said. 乐外网为您提供最优的考试服务
That rise was adding to storms such as that in the Philippines, although that single event couldn't be attributed to climate change, said Rahmstorf. 乐外网，学习考试培训网 "Of course the flooding from a given storm event would be less severe if we hadn't added those extra centimetres." CopyRight LeWai.com About 40 million people worldwide live in flood plains, said Southampton University's Robert Nicholls. That is 0.6 percent of the global population and 5 percent of global wealth, because of valuable assets such as airports and power plants. http://www.lewai.com乐外网 He was confident that coastal protection could hugely reduce lost land and assets. The cost of that speakers put at anywhere from 50 billion euros ($72.85 billion) a year by 2020 to up to $215 billion a year by 2100. http://www.lewai.com乐外网 乐外网为您提供最优的考试服务 (责任编辑：admin) |
