Swiss Plateau agrometeorological conditions from 1864 to 2050

Climate change will affect the agrometeorological conditions for crop and forage farming also in Switzerland. This can improve conditions for agricultural production but also increase weather-related risks. In this context, agrometeorological indices can help to better understand the interactions between crops and climate and thus serve as a basis for the development of adaptation strategies. This study investigates two important aspects of crop production, namely the length of vegetation period and drought risks. Our investigation relies on homogenized data series for temperature and precipitation spanning the period 1864-2009 and the latest climate scenarios from the European research project ENSEMBLES. Concerning the length of vegetation period, our results are consistent with the findings of earlier studies. For the Plateau, they suggest by 2050 an extension of about 40 days relative to the reference in the 1970s. Regarding drought risks the picture is less dramatic than previously assumed. This can be explained by the fact that for the first half of the 21st century the ENSEMBLES scenarios show on average only a small tendency toward reduced summer precipitation. On this aspect, however, even the new scenarios are fraught with uncertainty.