Hi all, love this board. Here is something some of you might find interesting:
http://www.timesonline.co.uk/tol/news/environment/article3181944.ece
The rate of annual ice loss in the Antarctic has increased by almost 80 billion tonnes in a decade, a study has found. Measurements using satellite radar readings revealed that in parts of the continent the rate of loss has speeded up by 140 per cent since 1996. Global warming is thought to be among the most likely factors and the data provides one of the most detailed assessments yet of the changes. The findings challenge suggestions from previous research that the overall quantities of ice and snow in Antarctica could increase over the next century because of greater snowfall. The total annual loss was estimated at 196 billion tonnes, almost 50 times as much as the 4 billion tonnes of drinking water supplied to Britain’s taps each year. The most extensive ice loss was found to be taking place in west Antarctica, where an estimated 132 billion tonnes disappeared in 2006. The annual loss increased by about 49 billion tonnes more than in 1996, when about 83 billion tonnes was calculated to have slipped into the water, mainly as icebergs. Related Links
On the Antarctic Peninsula the rate of loss was even greater, though the overall quantities were lower. It was estimated that the amount of ice loss rose from 25 billion to 60 billion tonnes. Quantities of ice and snow disappearing from east Antarctica were thought to be much lower, at 4 billion tonnes each year, and researchers concluded that the rate was unchanged since 1996.
Professor Jonathan Bamber, of the University of Bristol, was part of an international team of scientists that mapped changes in ice cover around 85 per cent of Antarctica’s coast.
“What we have done is make some observations that show a very substantial and dramatic change in the breadth of the ice sheet,” he said. “It suggests changes in the climate system could have a rapid influence on the health of the Antarctic ice sheet.
“This is another observation that confirms the trend in what’s happening around the world. We’ve seen the same thing in mountain glaciers, in Greenland, Patagonia and the same thing in Alaska. We are seeing the same thing everywhere we look.”
He was unable to say for certain that global warming was to blame but the ice loss from Antarctica is thought to be caused by warmer water temperatures, which in turn are caused by climate change and altered ocean currents. The loss is thought to be partly attributable to processes that take place over thousands of years.
“How it reponds to climate takes place over many different time scales,” Professor Bamber said. “There are changes taking place now that are a result of what happened to the climate 12,000 years ago.” Temperature rises caused by climate change are more pronounced at the poles than in other regions of the world but researchers have an incomplete understanding of the mechanisms controlling ice in Antarctica.
Data from the study will help scientists to establish how much ice and snow will be lost over the next century. Loss of ice on Antarctica has the potential to be the biggest cause of rising sea levels in coming decades. If it all melted, which scientists consider highly unlikely by 2100, it is estimated that sea level would rise 61-65 metres, compared with 7 metres if all of Greenland’s glaciers were to melt.