Climate change impacts in Switzerland

Climate change impacts in Switzerland - what the IPCC 4th Assessment Report has found:

• The duration of snow cover is expected to decrease by several weeks for each degree C of temperature increase in the Alps region at middle elevations. An upward shift of the glacier equilibrium line is expected from 60 to 140 m/ degree C. Small glaciers will disappear, while larger glaciers will suffer a volume reduction between 30% and 70% by 2050 [12.4.3].
• Observed effects due to changes in the cryosphere produced by warming include a 50% (15%) decrease in snow depth at an elevation of 440 m (2220 m) in the Swiss Alps (1975-1999) [1.3.1.1].
• Increased rockfall after the 2003 summer heat wave. Active layer deepening from 30% to 100% of the depth measured before the heat wave June-August 2003 Swiss Alps [1.3.1.2]
  
• Alps Formation of large lakes is occurring as glaciers retreat. These lakes have a high potential for Glacier Lake Outburst Floods (GLOFs) [1.3.1.1].
• In the Rhone River, there have been significant changes in species composition, as southern, thermophilic fish and invertebrate species have progressively replaced cold-water species [1.3.4.5] Changes in length of growing season, based on observations:
• 9 spring and 6 autumn phases have shown an established significant trend of lengthening 2.7 days per decade between 1951-1998 [1.3.5.1].
• Evidence of significant recent range shifts to higher elevation:
• A climate warming-induced upward migration of alpine plants in the high Alps was observed to have accelerated towards the beginning of the 21st century [1.3.5.2].
• Alpine summit vegetation elevational shift, increased species richness on mountain tops (due to increased temperature) [1.3.5.2].
• Climate-linked invasion of exotic thermophilous plants spreading into the native flora [1.3.5.3].
• Invasion of evergreen broad-leaved species in Alp forests and upward shift of Viscum album (Mistletoe) [Table 12.1].
• The Alps could be one of the regions most affected by increase in year-to-year variability in summer climates and thus a higher incidence of heat waves and droughts [12.3.1.2.].
• A 2 degrees C warming with no precipitation change would reduce the seasonal snow cover at a Swiss Alpine site by 50 days per year, and with a 50% increase in precipitation by 30 days [12.4.9].