The volume of most glaciers is smaller, according to a new study than previously thought. This has an impact on the fresh water supply, write the authors.
If less meltwater comes from the mountain, even rivers that require agriculture for irrigation, less water. The researchers around Daniel Farinotti from the Swiss Federal Institute of Technology Zurich published the study in the journal Nature Geoscience. The data are important in order to better assess the evolution of glaciers that shrink as a result of climate change.
The researchers estimated the ice volume from 215,000 glaciers to 158,000 cubic kilometers. That’s 18 percent less than the average of previous estimates. They took into account satellite imagery, glacier outlines, digital elevation models, and information about the glacial flow behavior. The sea ice and the contiguous ice sheets of Greenland and the Antarctic left her out of consideration. About half of the remaining glaciers lie in the Arctic regions, such as North America and Russia.
According to the new estimates, the glaciers of the Himalayas and other high mountain ranges together have only 7,000 cubic kilometers of ice, a quarter less than previously estimated. This is to be feared that the glacier area there in the 2060s – and not as previously thought in the 2070s – will be reduced by half. This has consequences for the water supply. The glaciers of Asia Minor feed large rivers such as Indus, Tarim and the tributaries of the Aral Sea. Hundreds of millions of people depend on it.