Evidence of past and future changes in health-related meteorological variables across Luxembourg

According to projections of climate models, air temperature will increase throughout the twenty-first century. The danger of heat exposure for the population is most severe in highly populated areas. Even relatively moderate levels of heat stress could be associated with adverse health impacts. Luxembourg, due to its high population density, is vulnerable to these effects. Up to now, no analysis of meteorological extreme values related to health impacts for the past and future climate conditions were available for Luxembourg. Climate indicators developed by the World Climate Research Programme's Expert Team on Climate Change Detection and Indices, as well as the physiological equivalent temperature were used to analyse data from (1) a long-term measurements side and (2) different regional climate models to assess potential health effects. In order to quantify the uncertainties related to climate change projections a multi-model ensemble of 16 projections from the ENSEMBLE Project at 25 km was used. In addition, a single model run with a spatial resolution of 1.3 km was conducted to analyse and quantify regional differences. The number of frost days is reduced by more than 40 days between the reference time-span and the last decade of this century. Tropical nights which did not occur in the reference time-span increased up to 11 events for the same time-span. The results for the physiologically equivalent temperature indicate a significant shift towards higher thermal stress levels for Luxembourg.