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Showing Original Post only (View all)Rate of arctic summer sea ice loss is 50% higher than predicted [View all]
Source: The Guardian
Sea ice in the Arctic is disappearing at a far greater rate than previously expected, according to data from the first purpose-built satellite launched to study the thickness of the Earth's polar caps.
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This rate of loss is 50% higher than most scenarios outlined by polar scientists and suggests that global warming, triggered by rising greenhouse gas emissions, is beginning to have a major impact on the region. In a few years the Arctic ocean could be free of ice in summer, triggering a rush to exploit its fish stocks, oil, minerals and sea routes.
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"Preliminary analysis of our data indicates that the rate of loss of sea ice volume in summer in the Arctic may be far larger than we had previously suspected," said Dr Seymour Laxon, of the Centre for Polar Observation and Modelling at University College London (UCL), where CryoSat-2 data is being analysed. "Very soon we may experience the iconic moment when, one day in the summer, we look at satellite images and see no sea ice coverage in the Arctic, just open water."
The consequences of losing the Arctic's ice coverage, even for only part of the year, could be profound. Without the cap's white brilliance to reflect sunlight back into space, the region will heat up even more than at present. As a result, ocean temperatures will rise and methane deposits on the ocean floor could melt, evaporate and bubble into the atmosphere. Scientists have recently reported evidence that methane plumes are now appearing in many areas. Methane is a particularly powerful greenhouse gas and rising levels of it in the atmosphere are only likely to accelerate global warming. And with the disappearance of sea ice around the shores of Greenland, its glaciers could melt faster and raise sea levels even more rapidly than at present.
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"The Arctic is particularly vulnerable to the impact of global warming," said Rapley. "Temperatures there are rising far faster than they are at the equator. Hence the shrinking of sea-ice coverage we have observed. It is telling us that something highly significant is happening to Earth. The weather systems of the planet are interconnected so what happens in the high latitudes affects us all."
Read more: http://www.guardian.co.uk/environment/2012/aug/11/arctic-sea-ice-vanishing?newsfeed=true
More details can be obtained at Neven's excellent Sea Ice Blog:
http://neven1.typepad.com/blog/2012/08/asi-2012-update-9-stormy-weather.html
Starting to look like the Ice Free moment could come in the next few years.