Extreme heatwaves in Europe 1950-2021: analysis of the links between meteorology, population, and impacts

Heatwaves have become more frequent and more intense under the influence of climate change, resulting in increased impacts on human health, infrastructure and economic activities. However, heatwaves climatic characteristics do not always inform properly on the actual human and material impacts resulting from heatwaves. In other terms, heatwaves with a high intensity in the climatological sense may not be equivalently as intense in terms of impacts. In this study, we empirically investigate, in Europe, the link between the climatic characteristics of heatwaves and their impacts, as listed in the EM-DAT disaster database. We apply indices available in the literature to characterize heatwaves for the 1950-2021 period found in the ERA5 and E-OBS datasets. We also propose new indices, combining meteorological and demographic data, that we compare to the existing ones, and to the heatwave’s impacts. We show that including demographic data in the heatwaves indices is key to ensure that heatwave climatic indices reflect more accurately the impacts of heatwaves. We also investigate the top 10 heatwaves that are considered extreme based on our best performing index but are not in the impact data-base and find references of their impacts for 8 of them, meaning that this type of methodology could be used to enrich existing impact databases by flagging events of interest.