Summer Heat Waves in Western Europe, Their Past Change and Future Projections

Abstract

Summer heat waves and extremely hot temperatures are a serious threat to society, the environment and the economy of Europe. In this chapter we present an overview of selected recent literature which looks specifically at European heat waves and extreme temperature events, their past change and expected future change from 1880 to 2100. Della-Marta et al. (2007b) show that over the period 1880–2005 the length of summer heat waves over western Europe has doubled and the frequency of hot days has almost tripled. These changes are seen in the probability density function (PDF) of western European daily summer maximum temperature (DSMT) as a significant change in the mean (+1.6 ± 0.4°C) and variance (+6 ± 2%). The relatively small change in variance over the last 126 years can explain approximately 40% of the change in hot days. We see a continuation of the observed trends in the future regional projections. Beniston et al. (2007) show that regional surface warming causes the frequency, intensity and duration of heat waves to increase over Europe. By the end of the 21st century, countries in central Europe will experience the same number of hot days as are currently experienced in southern Europe. The intensity of extreme temperatures increases more rapidly than the intensity of more moderate temperatures over the continental interior due to increases in temperature variability.