The 2003 heat wave as an example of summers in a greenhouse climate? Observations and climate model simulations for Basel, Switzerland

The heat wave that affected many parts of Europe during the course of summer 2003 may be a harbinger of summers that could occur more regularly in a future climate, under enhanced greenhouse gas concentrations. Switzerland was not exempt from the 2003 heat wave and, indeed, the previous absolute maximum temperature record dating back to the middle of the 20th century was exceeded by over 2 degreesC. Regional climate simulations undertaken for the European region emphasize the fact that summers will become progressively as hot as the 2003 event, such that in the latter pan of the 21 st century, it is likely to become the norm. On the basis of this study, the 2003 event should be considered as a "shape of things to come" and thereby prompt timely decision making in tennis of appropriate adaptation and mitiagation strategies. (C) 2004 Elsevier B.V. All rights reserved.