The volume of most of the mountain's glaciers, a new study found to be significantly lower than has been assumed so far. The data were important to the development of the climate change shrinking glaciers to better assess, write researchers Daniel Nine of the Swiss Federal Institute of technology (ETH) in Zurich in the journal Nature Geoscience. In mountain regions, the glacial impact on the freshwater supply, because if there is less melt drains water from the mountains, run the rivers, less water.
The researchers estimated the Ice volume of the world's total of 215 000 glaciers on 158 000 cubic kilometers. The to be seven percent less than in a comparable earlier study calculated. Take into account for satellite images, outlines of glaciers, digital elevation models, as well as information about glaziales flow behavior. The glaciers of the Arctic and Antarctic make up three-quarters of the total global volume, and are thus the most for the future sea-level rise is very important.
Alone in the Asian region depend on hundreds of millions of people from the melt water
In the glaciers of the Himalayas and other high mountains of Asia, only a fraction of this amount of Ice is stored, but they are for the local water budget is important. According to the new estimates, the high Asian glacier summarize 7000 cubic kilometres of ice, about a quarter less than previously estimated. So that is to be feared that the glacier area will already be contracted in the 2060er - and not, as previously assumed in the 2070er-years - by half. The consequences for water supply in high Asia.
The local glaciers provide large rivers like the Indus, the Tarim and the inflows of the Aral sea with water. Of hundreds of millions of people depend. Around the year 2090, the glacier-related could amounts of these rivers Drain in the summer months by 15 to 24 percent lower than today, the researchers write in the study. "This difference is disturbing. To the full extent more accurately gauge should be measured on the regional glacier volume is better," says Nine in a press release of the ETH.
Angelika Humbert, Alfred-Wegener-Institute for Polar - and marine research believes that in the future studies by the inclusion of even more data, such as the temporal Change of the Eishöhe, as well as the flow velocity and the direction of the glacier, can still deliver accurate results. In addition, the forecasts could be due to a more accurate physical modelling improves. In the current study, the results of up to five different computer models are already included. It was an important step in the right direction, as they give an Overview of the global Situation.