Modelling study estimates 2.3 million additional temperature-related deaths unless urgent action is taken to address changing climate
A modelling study, led by researchers from the Environment & Health Modelling (EHM) Lab at the London School of Hygiene & Tropical Medicine (LSHTM), suggests that climate change will likely result in a significant rise in deaths from heat across Europe, substantially surpassing any decrease in cold-related deaths.
This trend persists across climate change scenarios and even under high adaptation to heat, reinforcing the need for aggressive mitigation policies.
The study, published in Nature Medicine, estimates that changes to the climate could directly result in over 2.3 million additional temperature-related deaths in 854 European cities by 2099 if urgent action is not taken to cut carbon emissions. However, up to 70% of these deaths could be prevented if rapid action is taken.
The study suggests that even if enormous efforts were made to adapt cities to changing temperatures this would not be enough to balance increased health risks due to exposure to heat, especially in the most vulnerable areas such as the Mediterranean region, Central Europe, and the Balkans. Only swift cuts to carbon emissions that keep temperatures down were shown to reduce the number of extreme heat deaths.
Dr Pierre Masselot, lead author at the EHM-Lab at the London School of Hygiene & Tropical Medicine (LSHTM), said: "Our results stress the urgent need to aggressively pursue both climate change mitigation and adaptation to increased heat. This is especially critical in the Mediterranean area where, if nothing is done, consequences could be dire. But, by following a more sustainable pathway, we could avoid millions of deaths before the end of the century."
According to the modelling study, the ten European cities projected to see the highest temperature-related death tolls by the end of the century are as follows. The numbers represent projected cumulative increase in temperature-related deaths by 2099 due to climate change:
Barcelona (Spain) 246,082
Rome (Italy) 147,738
Naples (Italy) 147,248
Madrid (Spain) 129,716
Milan (Italy) 110,131
Athens (Greece) 87,523
Valencia (Spain) 67,519
Marseille (France) 51,306
Bucharest (Romania) 47,468
Genoa (Italy) 36,338
Due to their larger populations the highest numbers of temperature-related deaths are projected in the most populous Mediterranean cities, but many smaller cities in Malta, Spain and Italy are also likely to be badly affected with high temperature-related death rates.
Away from the Mediterranean region, impacts are expected to be less severe, with other European capitals such as Paris (13,515) projected to see a smaller, but still significant, increase in cumulative cold and heat deaths. On the other hand, most cities in the British Isles and Scandinavian countries could see a net decrease in deaths, one being London (-27,455). This lower death toll would however be massively outweighed by the increases in the rest of Europe, resulting in 2.3 million additional deaths across the whole of Europe.
Professor Antonio Gasparrini, senior author of the article and lead of the EHM-Lab at LSHTM, said: "This study provides compelling evidence that the steep rise in heat-related deaths will far exceed any drop related to cold, resulting in a net increase in mortality across Europe. These results debunk proposed theories of 'beneficial' effects of climate change, often proposed in opposition to vital mitigation policies that should be implemented as soon as possible."
This research uses risk functions of temperature in all cities, accounting for local and age-specific adaptation and acclimatisation. These are combined with projections of temperatures, population, and death rates to estimate expected temperature-related death tolls that can be attributed specifically to changing temperatures. The researchers considered a range of climate and epidemiological simulations to assess the uncertainty associated with the estimates, under scenarios defined for the IPCC sixth assessment report. The researchers additionally computed death tolls for scenarios in which the risk of mortality related to heat is reduced.
Adaptation scenarios devised in this research inform on the degree of risk reduction needed but remain abstract and do not inform on specific action to be taken. Additionally, this research focuses on daily mean temperature and does not account for specific weather events that could modify the estimated death toll such as extreme nighttime temperatures and humidity conditions.
Publication
Pierre Masselot et al. Estimating future heat-related and cold-related mortality under climate change, demographic and adaptation scenarios in 854 European cities. Nature Medicine. DOI: 10.1038/s41591-024-03452-2
