2.1.1.d Permafrost melting - rockfall

Permafrost is defined as surface material whose temperature is constantly under 0°C. In the Alps, it is generally found over 2300 m. It is estimated that 5 to 6% of the Swiss territory is covered by permafrost[1]. Permafrost also experiences the impacts of climate change. It is expected that the lower limit of permafrost will increase of 200-700 m if the temperature rises 1-2°C (Bader, Kunz et al. 2000). Melting of permafrost destabilizes soil. Engadine, Valais, Bernese Alps and the Tödi region are particularly affected. It is extremely likely that there will be problems related to infrastructures such as ski lifts and protection against avalanches because these are fixed in the permafrost. There will be a higher cost for repairs and restoration, in some cases causing the abandonment of the site. Moreover, hikers will be particularly affected by increased danger of falling rocks.