SLF Analysis Shows How Climate Change Will Affect The Avalanche Situation In Switzerland By End Of Century.
An SLF analysis shows how climate change will affect the avalanche situation in Switzerland by the end of the century.
Less snow does not mean fewer avalanches. This is the result of a study by SLF researcher Stephanie Mayer. She has investigated the consequences that climate change will have on avalanche activity in Switzerland above 1800 meters above sea level. "The number of dry avalanches will decrease, but above the tree line the increase in wet snow avalanches will partially offset this decrease," predicts Mayer. She has calculated the consequences for various climate scenarios. Only in the worst-case scenario, which assumes that average winter temperatures will warm by around five degrees Celsius by 2100, will overall activity decrease. "But then it will decrease by twenty to forty percent above the current tree line," says Mayer.
Ski resorts and avalanche warning services are facing new challenges. Over the course of the century, wet snow avalanches will increasingly occur during the peak tourist season. In wet snow avalanches, at least part of the snow cover in the avalanche starting area, the area in which the avalanche is released, has been moistened by meltwater or rainwater. In contrast to their dry counterparts, however, avalanche safety services can hardly trigger wet snow avalanches artificially, explains Mayer: "The only safety measure that helps is to close off endangered areas of a ski resort." Recreational athletes should also be more aware of the issue of wet snow avalanches, she says, as they become more common in mid-winter.
Mayer calculated her scenarios for seven locations in Switzerland, including the Weissfluhjoch above Davos and a station at around 2,700 m near Zermatt. However, she is certain that her results can be transferred to the entire Alpine region. As well as to mountain ranges with similar climatic conditions, such as the Columbia Mountains in Canada.
The good news: Due to rising temperatures, the associated higher snow line and less snow, avalanches may reach valleys less frequently in the future. But this does not apply in general. Extreme snowfall events will continue to occur in the future. This could even lead to larger avalanches, especially at high altitudes. If avalanches start at high altitudes and flow away in a channel, they can still penetrate as far into the valley as they do today. Nevertheless, Mayer expects the responsible authorities to review their hazard maps and, if necessary, adapt them to the changing hazard situation caused by climate change. The new climate scenarios (CH2025) should then also provide more precise analyses of future extreme situations.
