What are the costs of heat spell mortality in Europe's urban areas up to 2050?

The objective of this study is to estimate welfare economic costs of premature cardiopulmonary disease (CPD) mortality in Europe and Asia Minor under a middle-of-the-road scenario (SSP245) for global warming. It projects future heat-related CPD fatalities in urban areas over the next 25 years for 317 regions of 39 countries, by applying regionalized exposure-response functions for heat- and air pollution-related premature mortality. These functions are derived from datasets of daily counts of CPD deaths 1994–2018 for over 30 million people, capturing the different sensitivities to heat across climate gradients. As using simple average summer temperatures can mask important variations, methodologically we operationalize heat spell intensity based on the Eurostat metric of cooling-degree-days. We find that heat-related CPD mortality could triple by mid-century from its pre-1990 level. Based on OECD methodology for the economic valuation of premature mortality, this amounts to an estimated €90 billion in annual welfare economic costs. For ten countries in southeastern Europe, costs may well exceed 1% of their annual GDP, reaching up to 4% in a heatwave year. A further important outcome of the study stems from its exploration of the interactive effects of air pollution and heat spells for premature mortality. We find that deep reductions in air pollution, beyond requirements in EU’s recently revised Ambient Air Quality Directive, could prevent up to 190,000 heat-related deaths over the next 25 years, positioning air quality improvements as a critical adaptation strategy. Our findings underscore the urgency of better integrated climate and public health policies.