Beeinflusst die globale Erwärmung physiologisch relevante Klimafaktoren an der deutschen Nordseeküste?

Abstract

PURPOSE: Global warming raises the question whether climate changes are detectable on the German North Sea coast that are relevant to human physiology and health. METHODS: The analysis is based on publicly accessible meteorological data provided by the Deutsche Wetterdienst (German National Meteorological Service). Daily maximum temperatures were extracted from the time series of the measuring station List on the North Sea island of Sylt (Germany) for the period from 1937 to 2006. For comparative purposes, data measured in Westerland (Sylt) from 1996 to 2006 and at some inland stations were analysed as well. RESULTS: Annual frequencies of days when the daily maximum temperatures reached or exceeded 25°C (T max ≥25°C) were significantly higher in the second half of the time series than in the first half. The same holds true for the number of days when the maximum temperature reached or exceeded 30°C (T max ≥30°C). Four fifths of these hot days were observed in the second half of the period (1974 to 2006). The 15 year moving average of the annual frequency of days with T max ≥25°C exhibited a clear trend towards increasing frequencies. The annual frequencies of T max ≥25°C-days and hot days T max ≥30°C in List and in Westerland differed only slightly. Despite these increasing tendencies, hot days are still very rare on the North Sea Island of Sylt when compared to the respective frequencies observed at inland stations. CONCLUSIONS: The analysis of the time series of the daily maximum temperature indicates that hot temperatures are becoming more frequent even in maritime climate, while hot days are still very rare compared to inland locations. The results fit the scenario of global warming. With respect to human physiology, the increasing frequency of extreme temperatures is far more important than changes in mean values, since hot environmental conditions mean physical stress. Moreover, warm environments limit the ability to be physically active for instance within the context of exercise therapy.