搜尋此網誌

2019年1月16日星期三

南極融冰40年來加速280%,據新研究

南極融冰40年來加速280%,據新研究
Ice Melting in Antarctica Has Accelerated 280% In 40 Years, According to New Study

If glaciers in some parts of Antarctica took the #10YearChallenge, their selfie comparisons would be different but not exactly shocking to anyone who knows that global warming is real. What may surprise people though, according to a recent study, is the accelerated rate at which even the regions that were previously considered "safe" are melting away.

Published in Proceedings of the National Academy of Sciences, the study says that while the southernmost continent lost 40 billion tons of ice between 1979 and 1989, that number rose an incredible 280% in the last four decades, with an estimated 252 billion tons lost each year since 2009. By comparing the gains in annual snowfall to the amount of ice being lost in 65 different parts of Antarctica, the scientists found a clear imbalance. "The places undergoing changes in Antarctica are not limited to just a couple places," said Eric Rignot, lead author and Earth-systems scientist for the University of California at Irvine and NASA. "They seem to be more extensive than what we thought. That, to me, seems to be reason for concern."

It takes an estimated 360 billion tons of ice to raise the sea level a millimeter. That may not sound like a lot, but according to the study the seas have risen 7-8 inches since 1900. Now that the ice is melting 6 times faster than it was just 40 years ago, those extra inches of water are stacking up fast, which puts small islands and low-lying regions at risk of being completely destroyed. Some glaciers included in the study were found to be more vulnerable than others because of a combination of global warming, location, and slope. "It has been known for some time that the West Antarctic and Antarctic Peninsula have been losing mass, but discovering that significant mass loss is also occurring in the East Antarctic is really important because there's such a large volume of sea-level equivalent contained in those basins," said University of Waterloo glacier expert Christine Dow. "It shows that we can't ignore the East Antarctic and need to focus in on the areas that are losing mass most quickly, particularly those with reverse bed slopes that could result in rapid ice disintegration and sea-level rise."

The experts agree that more research is needed to make sense of what is happening and to come up with ways to fix it. We're not underwater yet, so it's not too late to act.







沒有留言: