Status: 06.01.2023 09:10 a.m
At least half of the world’s glaciers will disappear by the end of the century, a new study predicts. But there is room for manoeuvre. However, the authors see no hope for the German glaciers.
As a result of climate change, one in Specialist magazine “Science” According to a published study, around half of the world’s glaciers will disappear by the end of the century. Even with limited global warming to 1.5 degrees Celsius compared to the pre-industrial age, researchers estimate that 49 percent of all 215,000 glaciers will melt by the year 2100.
But the authors also have a positive message: Immediate measures to protect the climate and every tenth of a degree less warming can slow down the process.
Paris climate protection agreement not enough
According to the study, melting glaciers are linearly related to average global temperature rise. With an increase of two degrees – the target for maximum warming agreed in the Paris Agreement – almost 70 percent of glaciers up to a square kilometer in size could disappear. Almost 20 percent of the glaciers between one and ten square kilometers would melt completely.
Based on the climate pledges made at the UN COP26 climate conference in Glasgow in 2021 – on the basis of which a 2.7 degree increase in average global temperature by the end of the century was forecast – glaciers in many regions will almost disappear, as the study continues called. These included those of the European Alps, western Canada, the United States and New Zealand.
floods such as water scarcity
According to the study, with an average global temperature increase of four degrees, 83 percent of all glaciers worldwide would disappear by 2100. That would have dramatic consequences. Because the melting of the glaciers causes the sea level to rise. “Every millimeter of sea-level rise leads to more flooding in coastal areas, and glaciers are one of the main drivers of sea-level rise,” says Fabien Maussion from the University of Innsbruck, who is a co-author of the study.
In addition, the glaciers are natural freshwater reservoirs. “When they’re gone, it doesn’t mean that we don’t have water anymore, but that the water doesn’t come when it’s needed – namely in dry, hot summer months,” says Matthias Huss from ETH Zurich, another co-author of the study. When the ice has disappeared, water shortages are to be expected, especially during periods of drought. “This is a problem for irrigation, drinking water, transport of goods, fauna and flora and so on,” he says.
“Need a complete exchange rate”
Nevertheless, the team emphasizes that it is quite possible to slow down the melt in the medium term through immediate and comprehensive climate protection measures on a global scale. “Even if we can’t save the glaciers as they currently look, every tenth of a degree of warming saved causes a smaller decline and thus also less negative effects,” says Huss. “We need a complete exchange rate in terms of our emissions,” says Maussion.
With their calculations, the international team led by David Rounce from Carnegie Mellon University in Pittsburgh confirms previous findings on the extent of glacier melt. “The study took a very detailed look at various processes that could not previously be considered. But it is not the case that something completely new comes out of the study that was not previously known,” says glaciologist Olaf Eisen from the Alfred Wegener Institute , the Helmholtz Center for Polar and Marine Research. He was not involved in the investigation.
German glaciers can no longer be saved
Glaciers are large masses of snow, firn and ice, which usually flow slowly from mountains towards the valley. According to Eisen, the German glaciers can no longer be saved: “The issue is over.” Last year, the southern Schneeferner melted away, leaving only four glaciers in Germany. “They will meet the same fate,” says Eisen.
How fast the melt in Germany progresses depends only on the temperatures in the coming winters. “If we get winters like 2020 or 2021, when it was cold and wet in the spring, they might last another decade, but the German glaciers probably won’t reach 2050.”