Swiss Review 1/2019

Swiss Review / January 2019 / No.1 13 man-speaking region of the Alps and in Scandinavia shows growing inter- est: close to half of those surveyed have a positive opinion of snow pres- ervation. Admittedly, this does not replace snowmaking over a large area, but instead compensates for short periods of snowmaking in the pre-winter season – when it is too warm for snowmaking machines to operate. Level at which snow falls is rising dramatically Owing to global warming, average temperatures continue to rise even in winter – according to the latest CH2018 climate scenarios (see text box) by around 2–3.5 degrees Celsius in the case of Switzerland. Accord- ingly, scientists expect that by 2060 the snow line in winter will rise from today’s 850 metres to 1,500 metres above sea level. Without climate pro- tectionmeasures, the zero degree line inwinter could even climb by the end of the 21 st century to an elevation of 1,900metres – that is, up to the height of the Tschentenalp. In areas lying below 800 metres, winters with little snow are no longer the exception: since 1970 the number of snow days at this sea level has halved. The lack of snow is increas- ingly expanding to higher elevations: around half the snowpack below 1,000 metres might disappear by mid-century – most likely even by more than 80 percent by the end of the century. There, too, precipitationwill fall in the form of rain, which could lead to flooding. Warmer air absorbs more water. If global warming is not checked, heavy precipitation events in winter could be around 10 percent more intense – according to forecasts, even by around 20 percent by the end of the century. Glaciers lack “food” According to climate scenarios, most alpine locations have to reckon on less snowfall, particularly in spring. The low amounts of snow are fatal for the glaciers, which are increasingly de- prived of their “food”. Furthermore, the lack of a protective snowpack is ac- celerating the melting of the ice mass. Since 1850 alpine glaciers have lost around 60 percent of their volume. In the last ten years alone, one-fifth of the glacial mass has been lost. Inmany places the past winter 2017–18 was in- deed the snowiest in 20 years. In the warm and dry months of April and May, however, the thick snowpack quickly melted away. Added to that, the summer of 2018 was extremely dry (see “Review” 6/2018). Ever since measurements began to be taken 81 years ago, there has never been so little fresh snow in summer on the Weissfluhjoch at 2,540metres as there was in the past year. Artificial snow needs lots of water The drought also has an impact on water management in ski resorts. The production of artificial snow re- quires lots of water. In Davos, for ex- ample, around one-fifth of the mu- nicipality’s entirewater consumption is used annually in snowmaking. And the snowmaking machines are running exactly when the water level of rivers and streams is low. In recent years piste operators have conse- quently built more and more reser- voirs for water reserves. However, only two out of every three ski re- sorts that make artificial snow have such a reservoir. Without local water reserves, snowmaking during a drought will become more difficult: if the water is taken fromflowing wa- ters, a certain amount of residual wa- ter has to remain. Given the increas- ing dryness, that would lead to a conflict of interests. SLF Master’s student Pascale Josi surveyed 120 Swiss ski resorts about their use of water. Her conclusionwas that in every fourth ski resort there was a “potential for conflict” between water management and technical snowmaking. The researcher also asked ski resort operators from where they draw the water they use for producing artificial snow: 34 per- cent get their water from rivers and streams, 30 percent from the drink- ing water supply, 21 percent from springs and 15 percent from natural lakes. Especially following dry spells such as in recent years, water could become scarce, noted the researcher – particularly in inner-alpine valleys with little precipitation. Nationwide, though, the production of artificial snow is not immediately threatened: the Alps, as always, are regarded as “Europe’s water reservoir”. THEODORA PETER IS A FREELANCE JOURNALIST IN BERN ( SPRACHKRAFT.CH) A look at Swiss weather in the near future The CH2018 Climate Scenarios published in November show how climate change will affect Switzerland in the decades to come. This is the third report following those in 2007 and 2011 that climatologists from MeteoSchweiz, ETH Zurich and the University of Bern have produced on behalf of the Federal Council. Quantitative data is available for the first time, for example, about the expected amounts of precipitation associated with heavy rainfall. The report is online, linked to a web atlas and extensive databases for each region. https://www.nccs.admin.ch/nccs/en/home/climate-change-and-impacts/ swiss-climate-change-scenarios.html