The melt let the sea level rise by 27 millimeters since 1961.
Not only the ice sheets in Greenland and the Antarctic are melting. The glaciers worldwide have also lost more than 9000 billion tons of ice since 1961. This glacier melt alone caused the sea level to rise by 27 millimeters, as reported by an international research team with the participation of Innsbruck glaciologists in the journal “Nature”.
The scientists, led by Michael Zemp from the University of Zurich, have combined classic glacier observations with satellite measurements for their study. As a result, the researchers were able to access an unprecedented amount of measurement data right back to the 1960s. They could also rely on the comprehensive database of the “World Glacier Monitoring Service”, in which hundreds of researchers worldwide brought their satellite analyzes. “Our results are thus not based on predictions or numerical modeling,” explained Fabien Maussion from the Institute of Atmospheric and Cryospheric Sciences of the University of Innsbruck in a press release.
The researchers were thus able to reconstruct changes in the ice thickness of more than 19,000 glaciers worldwide. The measurements on the individual glaciers provided information about the annual fluctuations, while the satellite data made it possible to determine the total ice loss over several years or decades.
The biggest contributors to sea-level rise were the glaciers in Alaska, followed by the melting Patagonian ice fields and glaciers in the Arctic regions. The glaciers in the European Alps, the Caucasus, and New Zealand also lost significant amounts of ice, but due to their relatively small area, they only played a minor role in the sea-level rise.
Globally, glacier mass loss has increased significantly over the past 30 years, with global glaciers now losing 335 billion tonnes of ice per year. This melt contributes annually to a rise in sea level of just under a millimeter. Thus, the glacier’s melted ice accounts for 25 to 30 percent of the current rise in global sea level.
“Worldwide, we lose about three times the volume of ice stored in the entire European Alps – every year,” says Zemp. This loss of ice on all glaciers roughly corresponds to the mass loss of the Greenland Ice Sheet and clearly exceeds that of the Antarctic.