Glaciers are melting faster, losing 31 percent more snow and ice per year than they did 15 years earlier, according to three-dimensional satellite measurements of all the world’s mountain glaciers.
Scientists blame human-caused climate change.
Using 20 years of recently declassified satellite data, scientists calculated that the world’s 220,000 mountain glaciers are losing more than 328 billion tons (298 billion metric tons) of ice and snow per year since 2015, according to a study in Wednesday’s journal Nature. That’s enough melt flowing into the world’s rising oceans to put Switzerland under almost 24 feet (7.2 meters) of water each year.
The annual melt rate from 2015 to 2019 is 78 billion more tons (71 billion metric tons) a year than it was from 2000 to 2004. Global thinning rates, different than volume of water lost, doubled in the last 20 years and “that’s enormous,” said Romain Hugonnet, a glaciologist at ETH Zurich and the University of Toulouse in France who led the study.
Half the world’s glacial loss is coming from the United States and Canada.
Alaska’s melt rates are “among the highest on the planet,” with the Columbia glacier retreating about 115 feet (35 meters) a year, Hugonnet said.