In addition to the polar regions, the high mountains are among the places on earth where climate change is most noticeable. Already a few years ago, scientists predicted that of Bavaria's five alpine glaciers in just 30 years, only one will remain - only the northern Höllentalferner on the Zugspitze will still exist despite warming and lack of snow, so their prognosis. An international study came to the conclusion that the Alps will be particularly affected by the glacier loss of all the high mountains and ice caps of the earth. By the year 2100 ice losses threaten up to 75 percent. But for winter sports resorts and ski tourism in the Alps, another question is much more urgent: they need to know how the winter snowpack will develop in the future. "Experience shows that a snow thickness of at least 30 centimeters in the 100 days between December 1 and April 15 is the minimum required to economically run a ski resort, " explain Christoph Marty and his colleagues from the Swiss Federal Research Station for Forest, Snow and Landscape (WSL) in Davos.
Ski season is getting shorter
Whether these requirements will be met in the coming decades and where they have been examined in an extensive model study. For this they fed a model of alpine snow and surface processes with meteorological data and combined this with a simulation of future development based on different climate scenarios. For two different areas in the Swiss Alps - the Aare region in central Switzerland and the Grisons region in eastern Switzerland - they simulated future snow cover at different altitudes. They looked at the situation for the periods from 2020 to 2049, from 2045 to 2074 and from 2070 to 2099.
The result: Regardless of the coming extent of climate change, the snow season in the Alps will definitely be shorter in the future and the snowpack thinner. How strong the snow fall, however, depends on the altitude and the climate scenario, according to the researchers. The most affected are the altitudes between 1000 and 1500 meters - a height in which a large part of the ski areas is located. "At around 1, 000 meters altitude, the snow season currently lasts about four months - from December to the end of March, " say Marty and his colleagues. "At the end of this century, there will be virtually no snow at this altitude with almost unchecked warming." According to their predictions, the ski season will begin two weeks later in 2035 at an altitude of 1500 meters and stop two weeks earlier. By 2085, snow cover time will shrink by 13 weeks.
Shift to higher altitudes
Also, the amount of snow will decrease significantly: If the warming is limited to two degrees, then the snow cover shrinks by up to 30 percent by the end of the century, so the researchers forecast. If there is hardly any effective climate protection, then it will be up to 70 percent less snow. The reason for this: Due to the warming, the winter precipitation falls more frequently than rain instead of snow. The climate in the altitudes of the Alps shifts thereby: Snow conditions like today on 1000 meters will give it in the middle of the century only on 1200 to 1500 meters height, by the end of the century even only on 1700 to 2000 meters height. "At the end of this century, Davos at an altitude of 1560 meters will only have ten days more snow than today's Chur at only 593 meters, " explain the researchers. "In Adelboden at 1350 meters, there will be less snow than today in Bern." Good conditions for winter sports could then be in the worst case, only above 2500 meters altitude. display
For the ski resorts and the inhabitants of the Alpine region this would be fatal. "Many places in the Alps are heavily dependent on winter tourism, the economy and society of these regions will definitely suffer, " explains co-author Sebastian Schlögl of the SLF. If there is little or no snow for several winters, the livelihood of tens of thousands of people in the Alpine region would be threatened. In addition, the increasingly sparse snow cover also influences the amount of melt water that flows off in the spring. In summer, the rivers of the Alpine region could thereby lead significantly less water than before. This would have noticeable consequences for agriculture, the production of electricity through hydropower, but also shipping. After all, there is also a little hope: If it succeeds in limiting global warming still to two degrees, then at least could predict the end of the century predicted consequences, so the prognosis of the scientists. Although the snow cover and duration of the ski season will continue to shrink until 2050, the situation could stabilize thereafter.
- Christoph Marty (Swiss Federal Research Institute for Forests, Snow and Landscape (WSL), Davos) et al., The Cryosphere, doi: 10.5194 / tc-11-1-2017