WASHINGTON — Earth’s glaciers are melting much faster than scientists thought. A new study shows they are losing 369 billion tons of snow and ice each year, more than half of that in North America.
The most comprehensive measurement of glaciers worldwide found that thousands of inland masses of snow compressed into ice are shrinking 18% faster than an international panel of scientists calculated in 2013.
The glaciers are shrinking five times faster now than in the 1960s. Their melt is accelerating due to global warming and adding more water to rising seas, the study found.
“Over 30 years suddenly almost all regions started losing mass at the same time,” said lead author Michael Zemp, director of the World Glacier Monitoring Service at the University of Zurich. “That’s clearly climate change if you look at the global picture.”
The glaciers shrinking fastest are in Central Europe, the Caucasus region, western Canada, the Lower 48 United States and New Zealand. Glaciers in these places on average are losing more than 1% of their mass each year, according to a study in Monday’s journal Nature.
“In these regions, at the current glacier loss rate, the glaciers will not survive the century,” Zemp said.
Zemp’s team used ground and satellite measurements to look at 19,000 glaciers, far more than previous studies. They determined that southwestern Asia is the only region of 19 where glaciers are not shrinking.
Since 1961, the world has lost 10.6 trillion tons of ice and snow, the study found. That’s enough to cover the Lower 48 in about 4 feet of ice.