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Glaciers across the Himalayas are melting at an extraordinary rate, with new research showing that the vast ice sheets there shrank 10 times faster in the past 40 years than during the previous seven centuries. From a report: Avalanches, flooding and other effects of the accelerating loss of ice imperil residents in India, Nepal and Bhutan and threaten to disrupt agriculture for hundreds of millions of people across South Asia, according to the researchers. And since water from melting glaciers contributes to sea-level rise, glacial ice loss in the Himalayas also adds to the threat of inundation and related problems faced by coastal communities around the world. “This part of the world is changing faster than perhaps anybody realized,” said Jonathan Carrivick, a University of Leeds glaciologist and the co-author of a paper detailing the research published Monday in the journal Scientific Reports. “It’s not just that the Himalayas are changing really fast, it’s that they’re changing ever faster.”

Scientists have long observed ice loss from large glaciers in New Zealand, Greenland, Patagonia and other parts of the world. But ice loss in the Himalayas is especially rapid, the new study found. The researchers didn’t pinpoint a reason but noted that regional climate factors, such as shifts in the South Asian monsoon, may play a role. The new finding comes as there is scientific consensus that ice loss from glaciers and polar ice sheets results from rising global temperatures caused by greenhouse-gas emissions from the burning of fossil fuels. Many peer-reviewed scientific studies have identified human activity as a cause of rising global temperatures. So did a report issued in August by the United Nations Intergovernmental Panel on Climate Change, which said “human influence is very likely the main driver of the global retreat of glaciers since the 1990s.” For the new study, Dr. Carrivick and his colleagues scanned satellite photos of almost 15,000 glaciers in the region for signs of the large ridges of rock and debris that glaciers leave behind as they slowly grind their way through the valleys. Using the locations of these ancient glacial tracks, the scientists estimated the span of ice sheet coverage in previous centuries.

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