Torrential summer rainstorms are set to become more common—and more severe—in the Alps. A new study by scientists at the University of Lausanne warns that a 2°C rise in regional temperatures could double the frequency of short, extreme rainfall events in alpine areas.
The research, published on nature.com, draws on data from nearly 300 meteorological stations across Switzerland, Germany, Austria, France and Italy. It focuses on intense, short-duration precipitation episodes—lasting from 10 minutes to one hour—recorded between 1991 and 2020. By combining this data with physical principles and climate projections, the researchers developed a statistical model linking temperature increases to rainfall extremes.
One striking case was cited: in June 2018, Lausanne was inundated with 41mm of rain in just ten minutes. The resulting floods caused CHF 32 million in damage. Events like this could become more common.
Warmer air holds more moisture (around 7% more per degree), intensifying storm activity. The Alps, which are warming faster than the global average, are particularly exposed. The study predicts that an extreme storm previously expected once every 50 years could occur as often as every 25 years under a 2°C warming scenario.
Even a 1°C rise, says lead author Nadav Peleg, would pose serious challenges: sudden deluges can overwhelm soil absorption and urban drainage systems, increasing the risk of flash floods, landslides and debris flows. The implications for infrastructure are significant.
Planning for such changes, the researchers argue, is urgent. Measures such as modernised drainage infrastructure and revised spatial planning will be essential.
It seems adaptation is now an inevitable need. Our inability to mitigate climate change globally means we must also focus on resilience—because more destructive storms are coming.
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Study (in English)
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