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| World Home » Science & Technology » | Thu. Nov 20, 2008 |
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Arctic ice vanishing at a much faster rate MIL/Agencies/NDTV, Dec 13, 2006. San Francisco, December 13, 2006 - Scientists has warned on Monday that the Arctic ice is vanishing at a higher rate than previously thought, thereby adding to the global warming. The ice has been shrinking steadily over the past 30 years, but now scientists say there's a possibility of an ice-free Arctic in the next few decades. "We have a decline in the surface area covered by sea ice of 8 percent per decade for the last 30 years," said Assistant Professor Bruno Tremblay, of McGill University in Montreal. "So what we've been doing is running a couple climate global models like these are models which includes the ocean the atmosphere the sea ice and we're running those models into the future and we're trying to see what the reaction of sea ice cover is to the increase of CO2 (carbon dioxide) in the atmosphere which is a greenhouse gas." Scientists also warned that carbon dioxide emissions linked to global warming were cooling and shrinking the outermost atmosphere where the International Space Station and other satellites orbit. The findings were presented at a meeting of the American Geophysical Union in San Francisco. In November, Arctic ice coverage was about 800-thousand square miles (2 million square kilometres) below average - the least amount of sea ice ever recorded by satellites. It would, he said, mean a warmer climate and a loss of permafrost beach erosion on the Arctic Ocean. Arctic wildlife, such as polar bears and walruses, would be under threat because they needed the ice as a fishing and hunting ground. "If you're losing your ice you're also going to have a global effect," he said. "It could influence the storm tracks, the precipitation pattern even at high altitudes, so there's a huge local effect and there's also a global effect of the loss of the sea ice cover in the Arctic Ocean." He said the loss of the Arctic ice could come sooner rather than later. "What we've been finding really is that it's not going to be a steady decline like what we've been observing in the last three decades, but rather you reach a point sometime when there's like a tipping point," Tremblay said. "You reach a point where it's no longer a steady decline but it's a rapid decline and you lose all your ice within a decade or so and that could be happening much earlier than it would happen if we just extrapolated this linear decrease that we've been observing in the last three decades." Carbon dioxide emissions The thinning of the thermosphere, which begins about 60 miles (100 kilometres) above Earth and extends up to 400 miles (650 kilometres), reduces the drag on orbiting spacecraft, keeping them airborne longer. But the downside is that the lifetime of space junk is also extended, posing a threat to satellites. Full Story:
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