Climate Change Scenarios

Switzerland's climate is undergoing a process of change. The Swiss Climate Change Scenarios make it possible to evaluate the climatic evolution of the 21st century. They show expected changes in temperature and precipitation for various different assumptions on future global greenhouse gas emissions. Irrespective of the assumptions, temperatures are set to rise in all regions and seasons up until the end of this century.

The current climate change scenarios have been developed by Swiss researchers for the "Swiss Climate Change Scenarios CH2011" initiative, led by the ETH Zurich and MeteoSwiss. The results, published in 2011, pull together the latest knowledge on climate change in Switzerland, as all relevant studies that were available at the time were fed into the model simulations. The changes that can be expected to occur in temperatures and precipitation were given for three Swiss regions: north eastern, western and southern Switzerland.

A view of the future

The climate of Switzerland over the course of the 21st century can be expected to be significantly different to our historic and present climate. Average temperatures will most probably rise by several degrees in all seasons. According to scenario A1B, by the end of the 21st century, all regions covered by the simulation are set to see a rise in temperature of between 2.7 and -4.1 °C above that of the 1980-2009 comparison period (black horizontal line on the chart), whilst the average summer precipitation is predicted to decrease by 18-24%. In scenario A2, an annual rise in temperature by 3.2-4.8 °C can be expected, with a 21-28 % decrease in precipitation in the summer months.

In the case of the stabilisation scenario of RCP3DP, the climate of Switzerland would experience less significant change over the coming decades. Up to the end of the 21st century, this scenario predicts an average annual rise in temperature by 1.2-1.8 °C, which is similar to the degree of warming which occurred between 1864 and 2010. An 8-10% reduction in summer precipitation can be expected.

Extreme climatic events

It can be assumed that there will be more frequent, more intense and longer-lasting periods of hot weather and heat waves in summer, whilst the number of cold winter days and nights looks set to decrease. Whilst projections of the frequency and intensity of precipitation events are hampered by greater levels of uncertainty, the possibility of substantial changes occurring cannot be ruled out. Moreover, we can expect a shift from snow to a greater amount rain, which would increase the risk of flooding, particularly in low-lying areas. At the moment, it is not possible to make sound predictions about changes in the occurrence of gales and highly complex weather events such as hail or tornadoes.

New projections for Swiss Climate Change Scenarios

New climate change scenarios have been generated for CH2018, based on the most recent simulations for climate across Europe, and drawing on the latest scientific knowledge. The new scenarios will be published in 2018 and replace the scenarios currently in use which were generated in 2011.

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