Antarctica’s sea ice increasing due to ozone hole, but scientists predict global warming will catch-upJeremy Hance
April 23, 2009
"Our results show the complexity of climate change across the Earth. While there is increasing evidence that the loss of sea ice in the Arctic has occurred due to human activity, in the Antarctic human influence through the ozone hole has had the reverse effect and resulted in more ice,” says lead author John Turner from the British Antarctic Survey (BAS). “Although the ozone hole is in many ways holding back the effects of greenhouse gas increases on the Antarctic, this will not last, as we expect ozone levels to recover by the end of the 21st Century. By then there is likely to be around one third less Antarctic sea ice."
Published in Geophysical Research Letter the study by scientists from NASA and BAS found that the hole in the ozone layer strengthened surface winds in Antarctica while deepening storms in the South Pacific, leading to more cold air over West Antarctica which in turn has caused the increase in ice production.
Satellites have revealed that ice loss and production in Antarctica is highly variable, with some regions experiencing warming and loss of ice while other regions the opposite due to the ozone hole. Since the 1970s satellite images have shown that Antarctic ice has increased about 100,000 square kilometers (62,100 square miles) per decade. The researchers say this increase is not very great, about 0.97 percent per decade.
"Understanding how polar sea ice responds to global change – whether human induced or as part of a natural process – is really important if we are to make accurate predictions about the Earth's future climate,” Turner adds. “This new research helps us solve some of the puzzle of why sea-ice is shrinking is some areas and growing in others."
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