RSOE EDIS - Climate Change Monitor | Arctic sea ice at second lowest level

03.07.2009 12:57:22
Source: The Globe and Mail

Arctic Ocean sea ice has melted to the second lowest minimum since satellite observations began, according to scientists at the U.S. National Snow and Ice Data Center. Sea ice melt recorded on Monday exceeded the low recorded in 2005, which had held second place. With several weeks left in the melting season, ice in summer 2008 has a chance to go below last year's record low, the scientists at the University of Colorado said.

Environmental groups said the ice melt is another alarm bell warning of global warming. “It's an unfortunate sign that climate change is coming rapidly to the Arctic and that we really need to address the issue of global warming on a national level,” said Christopher Krenz, Arctic project manager for Oceana. “This is not surprising, but it is alarming,” said Deborah Williams, a former Interior Department special assistant for Alaska. “This was a relatively cool summer, and to have ice decrease to the second lowest minimum on record demonstrates that global warming's ongoing impact is profound.” The centre, based at the University of Colorado, reported that the ice melted below the 2005 minimum of 5.3 million square kilometres set on Sept. 21 that year. Exact figures were to be released later Wednesday. Through the beginning of the melt season in May until early August, daily ice extent for 2008 closely tracked the values for 2005, the centre said. In early August 2005, the decline began to slow. In August 2008, however, the decline has remained steady at a brisk pace. The most recent retreat primarily reflects melting in the Chukchi Sea off Alaska's northwest coast and the East Siberian Seas off the coast of eastern Russia, the center said. The Chukchi Sea is home to one of two populations of Alaska polar bears.

Federal observers flying for a whale survey on Aug. 16 spotted nine polar bears swimming in open ocean in the Chukchi Sea. The bears were 25 to 105 kilometres off the Alaska shore. Some were swimming north, apparently trying to reach the polar ice edge, which on that day was 645 kilometres away. Polar bears are powerful swimmers and have been recorded on swims of 160 miles, but the ordeal can leave them exhausted and susceptible to drowning in high seas. Sea ice is their primary habitat, where they hunt their favourite prey – ringed seals – which create lairs on ice for breeding and which maintain breathing holes through the ice. Summer sea ice last year shrank to about 4.27 million square kilometres, nearly 40 per cent less than the long-term average between 1979 and 2000. Most climate modelers predict a continued downward spiral, possibly leading to an Arctic Ocean that is ice free during the summer months by 2030 or sooner. Mr. Krenz said the announcement Tuesday showed that last year's record-low sea ice was not an anomaly. As ice covers fewer square kilometres of ocean, he said, warming will accelerate.

“It's going to accelerate climate change through changes in the reflectance of the Arctic,” he said. “It's going from bright ice to a much darker ocean.” More square kilometres of dark ocean will absorb more heat. More warmth will accelerate melting of Arctic permafrost, allowing organic matter now frozen to melt and add to the greenhouse gas problem, he said. “That allows for the breakdown of that by bacteria and other organisms that release CO2 or methane, depending on how the breakdown occurs,” he said. The effects faced by people in the Arctic eventually will reach the rest of the nation and the world, he warned.