Burden and projected changes in temperature-related mortality in 1368 European regions: a modelling study. Image credit: Kuki Ladron de Guevara / Shutterstock
The study estimates temperature-related mortality risks across Europe and predicts that climate change and an ageing population will lead to increased heatstroke deaths, especially in southern regions.
In a recent study published in The Lancet Public Health, researchers estimated current and future temperature-related mortality risks under four climate change scenarios for Europe. They examined significant regional disparities in mortality rates in 1,368 regions across 30 European countries, including specific disparities in Eastern, Scandinavia, and Southern Europe.
background
Climate change is likely to have adverse effects on physical, mental and community health through extreme weather events, increased infectious diseases, air pollution and poor food and water quality. Particularly in Europe, these changes are expected to exacerbate existing regional health disparities. Low and high temperatures have significant impacts on human health, increasing heatstroke and mortality and posing new challenges to population health systems.
The social and economic impacts of heatstroke mortality in Europe require broad-based interventions but also fine-grained adaptation strategies. Evidence on temperature-related mortality is scarce, especially in Europe, with most studies focusing on Western countries, often ignoring the specific challenges faced by Scandinavia and Eastern Europe.
Assessments of future mortality have focused primarily on heatstroke deaths, and interactions between demographic factors and region-specific characteristics have not been fully explored. Regional assessments are crucial for successful public health interventions and adaptation measures.
About the Research
In the study, the researchers calculated temperature-related deaths in a comprehensive dataset covering 1,368 locations in 30 countries, including all 27 European Union member states, Norway, Switzerland and the UK. They calculated the future mortality burden under different levels of climate mitigation.
The researchers estimated mortality caused by suboptimal temperature in 1,368 European regions using age-specific data and regional-level socio-economic vulnerability, such as regional GDP per capita and age distribution. They used a three-step approach to project temperature-related risk across time and space. They used Eurostat's City Audit database to extract city- and age-specific exposure-response functions (ERFs) for 854 cities.
The research team used 11 climate models developed based on the Coordinated Regional Climate Downscaling Experiment (CORDEX)-CMIP5 simulations and EUROPOP2019 population projections to project mortality rates from 1991 to 2020 under current conditions and four global warming levels (1.50°C to 4.0°C increase). This extensive modeling approach allowed them to identify future geographic locations where temperature and demographic changes would increase mortality risk. The team used temperature-related mortality risk estimates to calculate minimum mortality thresholds, percentiles, and excess mortality rates for both hot and cold climates.
In this study, we used 11 bias-adjusted regional climate models using CORDEX-CMIP5 data. The models were run under two Representative Concentration Pathways (RCPs), RCP 4.5 and RCP 8.5, and bias-adjusted using the transfer function method against the E-OBS daily gridded observational datasets of precipitation, temperature, and sea level pressure over Europe.
The researchers analyzed Eurostat regional account data to explore associations between temperature-related deaths and variables other than climate and individual characteristics. They utilized Eurostat 2019 GDP per capita data at NUTS 3 level, based on the 2016 edition of NUTS. The team looked at mortality rates under a range of climate and population scenarios, including combinations of current climate and population, future climate and population exposure, and future climate and future population exposure at different levels of warming. This multi-scenario analysis provided important insights into how socio-economic and demographic changes interact with climate change to exacerbate or mitigate mortality risks.
result
From 1991 to 2020, Eastern Europe experienced 2.5 times as many cold deaths as Western Europe, and Southern Europe experienced six times as many heat deaths as Northern Europe. The analysis found that socio-economic factors, such as regional GDP per capita, strongly influenced these disparities. There were 363,809 cold deaths and 43,729 heat deaths, with a ratio of cold to heat mortality of 8.3:1, varying considerably between regions from 3.3:1 in Slovenia to 132.5:1 in Ireland. Rising temperatures, ageing populations, and widening regional disparities could lead to an increase in temperature-related deaths of between 41,850 and 96,072 per year under some warming scenarios.
A 3.0°C increase in temperature is projected to result in 54,974 additional deaths by 2100 due to rising heat mortality and an aging population. This increase would result in a 2.6:1 ratio of cold to heat mortality. Regional differences will be particularly pronounced for heat mortality, with the south projected to experience 9.3 times as many deaths as the north. In Europe, heat deaths could increase to more than 234,455 per year by 2100, and some regions may see a shift in peak mortality from the cool to the warm season.
Heat deaths are 20% more variable than cold deaths, and both distributions are positively skewed. The study finds a significant positive correlation between regional GDP and heat deaths, suggesting that economically vulnerable regions may face higher risk. Heat deaths are also influenced by socio-economic variables, with a positive correlation between regional GDP per capita and mortality risk. Temperature-related mortality in Europe will change, with median cold and heat deaths decreasing by the end of the century. Mortality will be highest among people aged 85 years and over, especially in Southern Europe.
Our findings highlight the spatial heterogeneity of temperature-related mortality risk in Europe, mainly due to climate change and population ageing. These disparities are further exacerbated by socio-economic vulnerability, suggesting the need for targeted public health interventions.
The findings could help policymakers address extreme heat and reduce health disparities by prioritizing the protection of vulnerable communities and older adults. In particular, health authorities should develop targeted adaptation and resilience strategies for high-risk areas in Southern Europe, where socio-economic and climatic factors combine to increase the risk of mortality. Combining study data with regional-level susceptibility indicators could help prioritize public health adaptation initiatives in Europe, which is crucial to minimize the expected widening of health disparities.
