PARIS, Aug. 31 (AFP) – The number of glacial lakes has soared by 50 percent over the past 30 years, according to a new study based on satellite data. Excerpts are as follows:
The findings, published Monday local time in the journal Nature Climate Change, will help scientists and governments determine the risks that groups downstream of these often unstable lakes may face, he said.
They will also better understand how – and how quickly – water from glaciers melts into the ocean, improving the accuracy of predicting sea level rise.
Earlier studies showed that between 1994 and 2017, the world’s glaciers, especially in high mountain regions, fell by about 6.5 trillion tons.
“Over the past 100 years, 35 percent of the global sea level rise has come from melting glaciers,” said Anders Levelman, a professor of climatology at the Potsdam Institute for Climate Impact Research. “
Other major causes of sea level rise are the expansion of the ice sheet and sea water as they warm.
Since the pre-industrial era, the Earth’s average surface temperature has risen by 1 degree Celsius, but in alpine regions around the world it has risen twice as fast, accelerating the melting of glaciers.
Unlike normal lakes, glacial lakes are unstable because they are often intercepted by ice or sediments made up of loose rocks and gravel.
Large-scale flooding can occur downstream when accumulated water breaks through these accidental barriers.
The study, published in the journal Nature Climate Change, says the floods, known as glacial lake bursts, have killed thousands of people in the last century and destroyed many villages, infrastructure and livestock.
In January, the United Nations Development Programme estimated that more than 3,000 glacial lakes had formed in the Kundash-Himalayan region, 33 of which posed an immediate threat that could affect 7 million people.
The new study, based on 250,000 scene data collected by NASA’s Landsat mission, estimates that the current glacial lake is more than 150 cubic kilometers, about a third of the size of Lake Erie in the United States and twice the size of Lake Geneva.
‘Ten years ago, it was impossible to process and analyze this data, ‘ Mr. Shuga said.