The consequences of climate change

Temperatures

Probably the most direct consequence of greenhouse gas emissions is that the climate will continue to warm up. In their report ‘Climate Change and Switzerland 2050’, the Swiss Advisory Body on Climate Change (OcCC) and ProClim predict more frequent and hotter heat waves in summer. Higher mean temperatures and higher minimum temperatures may also be expected in Winter. This will result in an upward shift in the snow line.

 

Precipitation

Forecasts should be approached with caution in this area. The most up-to-date report available, ‘Climate Change and Switzerland 2050’, predicts increased volumes and intensities of winter precipitation and describes the resulting consequences:

In mountain regions, more snow may be expected above the snow line and more rain below it. This may cause floods or increased avalanche activity. Less rain is expected in summer; it remains unclear as to whether more frequent bouts of heavy rainfall may also be expected in summer. Due to the shift towards more intense precipitation, flooding may arise more frequently in the Central Plateau, Jura and the Pre-Alps. Because the data have developed differently than expected in recent years, the report is currently being revised.

 

How does it affect natural hazards in Switzerland?

The trends highlighted by the measurement series from the past and their effects on natural hazards prompt the following conclusions on the advent of natural hazards:

Geschlossene Fensterläden als Schutz gegen die Hitze

Heat wave

The trends towards the development of extremes are most clearly observable in the temperatures. As a result of rising summer temperatures, the temperatures during warm periods will also increase in future. Climate models also support the assumption that the variability of the climate will intensify in future and extreme heat waves like that of summer 2003 could arise more frequently (OcCC/ProClim, 2007).

Shrinkage cracks in clay soil

Drought

Because the precipitation is distributed over fewer days and the water reserves available in the mountains (glaciers, snow) and soil (evaporation) will be smaller, longer and more frequent periods of drought may be expected. 

Forest damage Reust

Storms

The OcCC and ProClim forecast fewer but more severe storms in 2050 in their report.

Überschwemmung in Sarnen

Floods

Due to increased precipitation intensity, floods may arise more frequently in the Central Plateau, the Jura and the Pre-Alps. An increase in floods could also arise from the rise in winter precipitation in the form of rain or snow.

Unglückslawine Valzur

Avalanches

As a result of the increase in winter precipitation, more snow may be expected to fall above the snow line in winter. Increased avalanche activity must be expected in mountain regions as a result. 

Landslide at Lutzenberg

Landslides and rockfall

The rise in precipitation intensity not only means that flooding will become more likely but also that other processes strongly affected by water, such as landslides and debris flows, will also increase. Due to the thawing of the permafrost in the soil and the heat-related shrinkage of the glaciers, the destabilisation of slopes and risk of geological mass movements, such as rockfalllandslides and debris flows, are expected to increase. Geologically unfavourable regions dominated by flysch, molasse, Alpine slate and fine-grained slope debris are particularly vulnerable to such events.