Climate Change Linked to Majority of Heatwave Deaths in Europe, Study Finds

A study conducted by scientists from Imperial College London and the London School of Hygiene & Tropical Medicine estimates that around 24,400 people died due to heat across 854 European cities this summer. Of these, approximately 16,500 deaths—around 68%—are attributed to climate change, which intensified temperatures by up to 3.6°C.

A Deadly Impact Amplified by Warming

Researchers emphasize that even small increases in temperature can have dramatic consequences. A few degrees of additional heat can push vulnerable populations beyond their physiological limits, turning heatwaves into large-scale public health crises.

Earlier analysis from the same research teams suggested that climate change may have tripled the death toll during a major July heatwave, highlighting the growing severity of extreme weather events.

Hardest-Hit Regions and Cities

The most severe impacts from a single heatwave were recorded in Romania, Bulgaria, Greece, and Cyprus, where nearly 950 deaths occurred over just one week in late July. During this period, temperatures rose as much as 6°C above seasonal averages.

Among European capitals, Rome, Athens, and Bucharest reported the highest mortality rates relative to population. Across countries, Italy recorded the largest number of climate-related heat deaths, followed by Spain, Germany, and France.

Heatwaves: The ‘Invisible’ Disaster

Experts describe extreme heat as a “silent killer,” as many deaths occur indirectly. Rather than being recorded as heat-related, fatalities are often attributed to underlying conditions such as heart, respiratory, or kidney diseases that are worsened by high temperatures.

As a result, the true human cost of heatwaves is likely underestimated, with many cases going unreported or misclassified.

Unequal Impacts on Vulnerable Populations

The burden of extreme heat is not evenly distributed. Older individuals are particularly at risk, with more than 80% of heat-related deaths occurring among people over the age of 65. Those aged 85 and above account for a significant share of fatalities.

With Europe’s population ageing rapidly—and the continent warming faster than most regions globally—the risks associated with heatwaves are expected to grow in the coming decades.

Urban Heat and Rising Risks

Cities are especially vulnerable due to the “urban heat island” effect, where built environments trap heat and raise temperatures significantly above surrounding rural areas. With around 70% of Europeans living in urban areas—a figure projected to rise further—this effect is becoming an increasingly critical factor in heat-related mortality.

While many European countries have implemented heat-health warning systems and adaptation strategies, experts warn that these measures alone are insufficient to counter the scale of the threat.

A Call for Urgent Action

The findings underline a stark reality: adaptation efforts can reduce risks, but they cannot fully offset the impacts of continued global warming.

Researchers stress that without rapid reductions in greenhouse gas emissions, heat-related deaths will continue to rise. The study serves as a clear warning that climate change is not a distant problem—it is already having measurable and deadly consequences across Europe today.