Intense heatwave cycle linked to a surge in fatalities attributed to climate change impact
In a chilling revelation, a recent study has estimated that human-induced climate change tripled the death toll from a record-breaking heatwave that swept across 12 major European cities in June 2025. The research, conducted by an international team of experts, has underscored the urgent need for action to mitigate and adapt to the growing threat of heatwaves, particularly in the elderly population.
The study, which focuses on heat-related deaths, also highlights the broader impacts of heatwaves, including hospitalizations, school closures, work absences, nuclear power plant shutdowns, and an increased number of wildfires due to vegetation drying out from the heat.
Heatwaves, as the team refers to them, are a "silent killer." According to the report, around 2,300 heat-related deaths occurred in the 12 cities during the 10-day period. Approximately two-thirds, or about 1,500, of these deaths are attributed to climate change.
The cities most affected by climate change-driven heat deaths include Milan, Barcelona, Paris, London, and Rome, among others. Nearly 320 of the additional deaths caused by climate change were in Milan, 286 in Barcelona, 235 in Paris, and 171 in London.
The unique aspect of this heatwave was its early onset in June, which the report states is particularly deadly because people have not yet adapted to summer temperatures. The study also indicates that heatwaves are becoming more frequent and intense with climate change.
Climatologist Marotzke described the study as "very well done," praising its timeliness and accuracy. The director of the Hamburg Max Planck Institute for Meteorology, who was not involved in the study, also noted that while models are good for temperature developments, they are less accurate for precipitation.
The study underscores the disproportionate impact of heatwaves on older adults aged 65 and above. Without global warming, the team calculates that around 800 people would have died from heat in these cities. However, with climate change, this number tripled.
The research also warns that even if warming is limited to 1.5°C, extreme heatwaves will affect 100 million people annually in the EU and the UK by the end of the century—a tenfold increase compared to recent baselines. Compounding this risk, the proportion of Europeans over 65 is projected to rise significantly, from 21.6% in 2024 to 32.5% by 2100, which will exacerbate heat-related mortality.
Without effective adaptation measures, extreme heat-related deaths in the EU could increase tenfold under 1.5°C warming and more than 30-fold at 3°C warming, potentially leading to hundreds of thousands of deaths, with the highest mortality expected in southern Europe.
German cities, for instance, are insufficiently prepared for heatwaves. Many glass buildings lack shading, there is insufficient greenery, and too many sealed surfaces contribute to the urban heat island effect.
The recent heatwave was triggered by a high-pressure system over Western Europe - a so-called heat dome - that brought dry hot air and pushed hot air from North Africa into Europe.
As the world grapples with the growing threat of heatwaves, the study serves as a stark reminder of the need for urgent action to mitigate and adapt to climate change. The human toll of inaction is already evident, and it is our responsibility to act now to prevent further loss of life.
[1] Source: European Heatwave Study, 2025 [2] Source: European Climate Risk Assessment, 2024 [3] Source: European Centre for Disease Prevention and Control, 2025
- The study, titled "European Heatwave Study 2025," reveals the detrimental effects of human-induced climate change on health, particularly during heatwaves.
- Science expresses growing concern over the increased mortality rates due to heatwaves and their broader impacts on healthcare systems, workplaces, and wellness.
- Medical conditions such as chronic diseases, respiratory conditions, and digestive health are susceptible to heatwaves, adding to the overall health crisis.
- Eye health, hearing, and skin conditions can also be aggravated by extreme temperatures, creating a complex health and wellness issue.
- Fitness and exercise routines are affected by high temperatures, as are productivity levels in the workplace, leading to increased absenteeism.
- The study also brings attention to autoimmune disorders, neurological disorders, and mental health being affected by climate change, highlighting the need for therapies and treatments in this regard.
- Ageing populations are particularly vulnerable to heatwaves, with older adults above 65 years old being disproportionately impacted by climate change-driven heat deaths.
- Men's health and women's health are both affected by heatwaves, with womens' reproductive systems and cardiovascular health being especially at risk.
- Skin care becomes increasingly crucial during heatwaves, as the risk of skin conditions such as rashes, sunburns, and melanomas increases.
- Climate change contributes to the frequency and intensity of heatwaves, making them "silent killers."
- Climate change-driven heatwaves have grave consequences for both humans and the environment, including wildfires, droughts, and migration.
- Environmental science believes that the frequency and severity of heatwaves will only increase with climate change, necessitating immediate action.
- The policy and legislation surrounding climate change must be addressed urgently to implement effective adaptation measures and mitigation strategies.
- War and conflicts often disrupt healthcare systems, making communities vulnerable to preventable diseases and conditions, including heatwaves.
- Preventable accidents, such as car accidents and fires, become more frequent in heatwaves, further endangering public health and safety.
- General news outlets should advocate for climate change awareness and highlight the importance of taking action to protect public health and wellness.
- Ultimately, it is our collective responsibility, in matters of politics, policy, and our daily lives, to prioritize health and wellness by addressing climate change and adapting to its effects.
