Climate change set to dramatically increase heat-related deaths in Europe, with Southern regions most at risk

By Pooja Toshniwal PahariaReviewed by Susha Cheriyedath, M.Sc.Aug 27 2024

Temperature-related mortality burden and projected change in 1368 European regions: a modelling study. Image Credit: Kuki Ladron de Guevara / Shutterstock

Study estimates temperature-related mortality risks across Europe, projecting increased heat-related deaths, especially in Southern regions, due to climate change and an aging population.

In a recent study published in the journal The Lancet Public Health, researchers estimated present and future temperature-related mortality risks for four European climate change scenarios. They examined the pronounced regional inequalities in death across 1,368 areas in 30 European countries, including specific disparities in Eastern Europe, Scandinavia, and Southern Europe.

Background

Climate change can lead to adverse physical, mental, and community health outcomes due to increasing extreme weather events, infectious illnesses, diminishing air quality, and poor food and water quality. Particularly in Europe, these changes are expected to exacerbate existing regional health inequalities. Low and high temperatures significantly influence human health, increasing heat-related morbidities and fatalities and posing new difficulties to population health systems.

The social and economic consequences of heat-related mortality in Europe necessitate not only broad interventions but also finely-tuned adaptation strategies. The evidence on temperature-related deaths is sparse, especially in Europe, with most research focused on Western nations while often ignoring the specific challenges faced by Scandinavia and Eastern Europe.

Assessments of future mortality have primarily concentrated on heat-related fatalities, while the interplay between demographic factors and location-specific characteristics has been underexplored.  Localized evaluations are critical for successful public health interventions and adaptation methods.

About the study

In the present study, researchers calculated temperature-related deaths in a comprehensive dataset encompassing 1,368 areas across 30 nations, including 27 European Union Member States, Norway, Switzerland, and the United Kingdom. They calculated the future death load under various climate mitigation levels.

The researchers used age-specific data and local-level socioeconomic vulnerabilities, such as regional GDP per capita and age distribution,  to estimate mortality caused by suboptimal temperatures in 1,368 European locales. They used a three-phase technique to predict temperature-associated risk over time and space. They extracted city- and age-particular exposure-response functions (ERFs) for 854 cities using Eurostat's Urban Audit database.

The team predicted mortality for current conditions between 1991 and 2020, as well as four global warming levels (1.50°C to 4.0°C increase), using 11 climatic models developed based on Coordinated Regional Climate Downscaling Experiment (CORDEX)-CMIP5 simulations and EUROPOP2019 population projections. This extensive modeling approach allowed them to identify future geographical locations at higher risk of death owing to temperature and population structure changes. They used temperature-related death risk estimations to calculate minimum mortality thresholds, percentiles, and excess death rates for both heat and cold.

The study used 11 bias-adjusted regional climate models using the CORDEX-CMIP5 data. These models were run under two representative concentration pathways (RCPs), RCP 4.5 and RCP 8.5, and bias-adjusted using a transfer function method on the E-OBS daily gridded observational dataset for precipitation, temperature, and sea level pressure in Europe.

Researchers analyzed Eurostat regional account data to investigate the link between temperature-related deaths and variables other than climate and individual characteristics. They utilized Eurostat GDP per capita data for 2019 at the NUTS 3 level, based on the 2016 edition of NUTS. The team examined death rates for various climate and population scenarios, including present climate combined with population, future climate combined with population exposure, and future climate at varying warming levels mixed with future population exposure. This multi-scenario analysis provided crucial insights into how socioeconomic and demographic changes could interact with climate change to exacerbate or mitigate mortality risks.

Results

From 1991 to 2020, cold-related fatalities were 2.5-fold higher in East Europe than in West Europe, while heat-related deaths were six-fold higher in South Europe compared to North Europe. The analysis revealed that socioeconomic factors, such as regional GDP per capita, significantly influence these disparities. There were 363,809 cold-related fatalities and 43,729 heat-related fatalities for an 8.3:1 cold-to-heat mortality ratio, with considerable regional differences ranging from 3.3:1 in Slovenia to 132.5:1 in Ireland. Temperature-related fatalities would increase by 41,850 to 96,072 per year depending on the warming scenario, driven by rising temperatures, an aging population, and widening regional inequities.

A 3.0°C rise in temperature would lead to 54,974 more fatalities by 2100 as heat-related mortality rises and the population ages. This increase would yield a 2.6:1 cold-to-heat-related mortality ratio. Regional differences are likely to become more stark,  notably in heat-related mortality, with 9.3 times as many fatalities forecast in the south as in the north. Heat-related fatalities in Europe might rise to more than 234,455 per year by 2100, potentially moving the mortality peak from cold to warm seasons in some places.

Heat-related fatalities are 20% more variable than cold-related deaths, and both distributions skewed positively. The study found a significant positive correlation between regional GDP and heat-related mortality, suggesting that economically vulnerable regions might face higher risks. Heat-related fatalities are also influenced by socioeconomic variables, with a positive relationship shown between regional GDP per capita and mortality risks. Europe's temperature-associated mortality would shift, with the median ratio of cold-related to heat-related fatalities decreasing by the end of the century. The highest death rate will be among those over 85 years, particularly in southern Europe.

The study findings highlight the spatial heterogeneity in temperature-associated death risk for Europe, primarily due to climatic changes and an aging population. These disparities are further compounded by socioeconomic vulnerabilities, indicating the need for targeted public health interventions.

The findings could help policymakers reduce health disparities by addressing extreme heat and prioritizing safeguarding vulnerable locations and older populations. In particular, health authorities must develop targeted adaptation and resilience strategies for high-risk locations in South Europe, where socioeconomic and climatic factors converge to heighten mortality risks. Combining the study data with local-level susceptibility indicators might assist in prioritizing public health adaptation initiatives in Europe, which is critical for minimizing the expected increase in health inequities.