The pace of climate change is increasing: Due to global warming, global glacier melt has increased significantly in the last 20 years. in one “Nature” magazine According to a published international study, glaciers lost an average of 267 billion tonnes (gigatons) of ice per year between 2000 and 2019, but most of them in the last five years. Melting ice is now contributing more than 20 percent to sea level rise.
With lost gigatons of snow, Switzerland could sink up to six meters underwater each year, ETH Zurich, whose researchers were involved in the study, explained for clarity.
According to the study, with some exceptions, around 220,000 of the world’s glaciers are affected by the melt. Typically, apart from the polar ice cap, only a few hundred of them are under continuous observation. “There are many areas we didn’t know how they would develop,” says lead author Romain Hugonet.
“The situation in the Himalayas is particularly worrisome. The great rivers like the Ganges, Brahmaputra and the Indus receive a considerable amount of water by melting glaciers in the dry season. An ETT statement said the increase in meltwater is currently acting as a buffer for the people of the region. However, if the glaciers of the Himalayas continue to shrink at an increasing rate, such as populated states in the event that or Bangladesh There is a danger of lack of water or food in a few decades.
Billions of tons of snow is disappearing
For their study, Hughnet and his colleagues analyzed half a million previously unused satellite images. In this way, according to their own statement, they were successful in “the first complete list of melting glaciers in the world”.
According to Hugonnet, who researches at Eug Zurich and the University of Toulouse, it has grown significantly: while it averaged 227 billion tonnes per year between 2000 and 2004, the decline from 2015 to 2019 averaged 298 billion tonnes. Per year.
The findings of the study coincide with the assessment Intergovernmental Panel on Climate Change (IPCC), But are much more accurate, Hagonnet said. This particularly applies to the effects of glacier melting on sea level rise.
Hugonnet said that new, more geographically accurate figures could also help to create an adaptation strategy in densely populated areas, where glaciers play an important role in agriculture and water supply.
In the short term, melting glaciers can compensate for water scarcity in some areas, such as India or the Andes. But once the peak is exceeded, the amount of water will decrease rapidly until nothing is left, warns the researcher.
In some areas, the melting rate slowed down between 2000 and 2019, to surprise researchers. This was the case, for example, on the east coast of Greenland, Iceland and Scandinavia. Studies have attributed this to a weather anomaly in the North Atlantic. From 2010 to 2019, it caused high local rainfall and low temperatures, which slowed snow shrinkage.
According to ETH, the study results will now be included in the next IPCC status report.