Alps to Become More Dangerous in Warming World

Heat waves, floods, avalanches and other deadly natural disasters could become more common in mountainous regions thanks to climate change, a new study suggests, making the famous peaks more dangerous for mountaineers and skiers.

Extreme weather events are predicted to become more frequent on a warmer Earth. In the Eastern European Alps, two such events — the 2003 heat wave and the 2005 flood — gave researchers a preview of how similar events could pose a threat to alpine regions and local communities in and around the mountains.

Global climate models do not usually specify how climate change will play out in a given town or city. But for villages in the mountains' shadows or ski resorts nestled in the snowy slopes, natural features such as glaciers — if they become unstable — pose a hazard to the people living near them.

In the Alps, where temperatures have increased twice as much as the global average temperature since the late 19th century and are predicted to rise by an average of 0.54 to 0.9 degrees Fahrenheit (0.3 to 0.5 Celsius) per decade in the next century, these threats are a real concern.

The deadly European heat wave of 2003 scorched the Alpine glaciers and melted them to record lows, triggering avalanches and flash floods across the region. Melting permafrost — soil that's at or below freezing temperatures for at least two years — set off more rock falls across the European Alps.

The severe floods that occurred as a result of heavy rainfall in August 2005 were the most damaging for 100 years and led to high volumes of water and sediment being deposited downstream, costing millions in damage to buildings, railways, roads and industrial areas in Austria. In Switzerland, this disaster was estimated to have caused one quarter of all damage by floods, debris flows, landslides and rock falls recorded since 1972.

The biggest threats from events such as these are in high-altitude areas where there is mountaineering and skiing infrastructure. In addition, the impact of climate change is expected to be magnified in any snow or ice-covered regions, because melting snow drives further melting.

''While human activity and land management are important factors, we expect that global warming will cause ongoing and accelerating ice loss in the European Alps over the next decades and centuries," said study team member Jasper Knight of the University of Exeter in England. "This will have a significant impact on hazard type, location and frequency and a potentially negative effect on the region's economic engine – tourism.''

The study was published in the May 28 edition of the journal Philosophical Transactions of the Royal Society A.

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