Switzerland Climate Resilience Policy Indicator

Temperature

Switzerland’s warming is two to three times faster than the global average. Its average temperature increased 2°C between 1864 and 2016, and warming has been especially rapid in the last 50 years. The temperature rise has been uniform, without pronounced geographic or seasonal differences. The number of summer days (with maximum temperature above 25°C) doubled between 1961 and 2016, while the number of snow days decreased by more than three days per decade. Climate change is also affecting the country’s cloud cover, increasing the number of sunny days (days with relative sunshine duration larger than the 80th percentile) and reducing cloudy days (days with relative sunshine duration lower than the 20th percentile). Furthermore, the average water temperature of Switzerland’s rivers and streams increased by up to 1.2 ºC during 1954-2016, and by up to 1.5-3ºC in the summer.

Switzerland’s temperature is expected to continue rising. By the end of the century, its mean average annual temperature is projected to be 0.6-1.9ºC1 to 3.3-5.4ºC2 higher than during 1981-2020. Warming is likely to be more notable in the summer than the winter.

The rise in temperature is projected to increase the intensity, frequency and length of heatwaves and warm spells. There are likely to be 2 to 21 more very hot days3 per year by the end of century, and the increase in extreme heat events is expected to be greater in southern Switzerland than in the north. At the same time, extremes of cold weather are projected to become less intense and less common. For instance, the coldest night of the year during 2070-2099 could be up to 6.2-6.9 ºC warmer4 than in the 1981-2010 period.

Clearly, higher average temperatures are reducing Switzerland’s heating degree days (HDDs) and increasing its cooling degree days (CDDs). Between 1961 and 2016, the number of heating days (days with a daily average temperature below 12ºC) decreased 15‑20%, while the number of summer days doubled, modifying energy demand patterns. 2011 climate projections anticipate a heating demand drop of 8.2% to 20.6% by 2085 compared with 1980-2009, and a 200% to 750% rise in CDDs.5

The decrease in energy demand for heating and the increase for cooling may lead to a drop in oil product consumption and a rise in electricity use. Given the country’s overall energy consumption profile, the decline in heating demand is likely to outweigh the increase in cooling demand, leading to an overall gain in welfare and a decrease in carbon emissions.

Precipitation

No significant long-term trend in annual precipitation has been identified for the last 100 years, despite strong interannual variability. Meanwhile, the frequency of extreme precipitation events has increased by 30% and they are also more intense, with a 12% rise in annual 1-day precipitation maxima in the daily maximum precipitation of 1901-2016.

Climate projections indicate that winter precipitation could be 15% greater in 2070-2099 than in 1981-2010 under a high greenhouse gas emissions scenario.6 Heavy precipitation events are projected to become both more frequent and intense for all seasons and regions, but increases will likely be stronger in northern Switzerland and during the winter months (December to February).

During the winter, the intensification of precipitation patterns, coupled with a progressive shift from snowfall to rainfall (especially in low-altitude regions), is expected to augment the risk of floods by increasing runoff in the winter and early spring.

In the summer, different potential precipitation trends could have varying impacts. For instance, extreme precipitation events are projected to intensify by the end of the century, which could compromise energy system resilience (as happened when heavy rainfall in the Zofingen region in July 2017 caused flooding and power outages). At the same time, the overall number of wet days is expected to shrink and possibly lead to drier summers, as average summer precipitation could be up to 21% lower by the end of the century compared with 1981-2010 under a high greenhouse gas emissions scenario.7 These changes in seasonal precipitation and runoff may lead to higher hydropower generation in the winter and less in the summer.

Tropical cyclones and storms

Due to the high level of uncertainty regarding wind extremes and Switzerland’s complex topography, no significant trends in this area have been detected. Climate models therefore anticipate very little to no change in daily maximum wind speed throughout the century.8

The Federal Council's 2012 strategy consists of two parts: a plan for adaptation to climate change in Switzerland and a corresponding action plan. The first part establishes a framework for federal agencies to take co‑ordinated action towards climate change adaptation, identifying fields of action and setting goals.

Meanwhile, the second part elaborates an action plan. The first Action Plan 2014-2019, adopted in 2014, was subsequently replaced in 2020 by the second Action Plan 2020-2025.

The Action Plan 2020-2025 comprises 75 federal-level adaptation measures based on analysis of the 2018 Swiss Climate Change Scenarios. The action plan contains concrete measures for building energy sector climate resilience, and it outlines the time frame, cross-sector challenges, the scope of the intervention, resource needs and priorities. It identifies rising energy demand for cooling and lower hydropower generation in the summer as key challenges. To address these issues, it recommends gaining greater knowledge in these two areas, under the leadership of the Swiss Federal Office of Energy.

The Federal Office for the Environment (FOEN) published the Strategy and the Action Plans, and federal agencies will report on the plan’s implementation status at the end of 2022 and 2025, and will present an evaluation of its impacts in 2023. The FOEN also published the 2017 report Climate-Related Risks and Opportunities, which identifies and prioritises Switzerland’s climate-related risks and opportunities to 2060. Risks linked with the energy sector include declining energy production and the deterioration of energy infrastructure.

The legislative instruments and policies that form the basis of Switzerland’s sustainable and modern energy policy are: Federal Constitution articles dealing with energy; the Federal Energy Act; the Federal CO₂ Act; the Federal Act on the Utilisation of Hydropower; the Federal Act on Dams; the Federal Act on Pipeline Systems; the Federal Act on Electricity Installations; the Federal Nuclear Energy Act; the Federal Electricity Supply Act; and the Energy Strategy 2050. While these documents rarely address energy sector climate resilience, they do, however, highlight mitigation measures such as energy efficiency and renewables-based power generation.