Europe Faces Over 2 Million Climate-Linked Deaths by 2099, Study Warns

A major study published in Nature Medicine has issued a stark warning about Europe’s future. Led by the London School of Hygiene & Tropical Medicine (LSHTM), the research projects that rising temperatures driven by climate change could result in more than 2.3 million additional deaths across European cities by 2099.

Analyzing data from 854 urban areas in 30 countries, the study finds that while cold-related deaths may decline, the surge in heat-related fatalities will far outweigh any benefits, underscoring the urgent need for decisive carbon reduction and climate action.

Mediterranean and Central Europe at highest risk
The study identifies southern and central Europe, particularly Mediterranean cities like Barcelona, Rome, Naples, and Athens, as the most vulnerable. These regions already face frequent heatwaves, and factors such as ageing populations, dense urbanisation, and high baseline temperatures amplify their risk. By the end of the century, Barcelona alone could see more than 246,000 climate-linked deaths. The Balkans and Central European cities are also projected to experience significant spikes in heat-related mortality.

Northern Europe: a temporary reprieve
Countries in northern Europe, including Sweden, Finland, and Ireland, may initially see a drop in deaths due to fewer cold-related fatalities. However, this benefit is short-lived. As heat extremes intensify later in the century, traditionally cooler cities such as Helsinki and Stockholm are expected to experience net increases in heat-related mortality, raising concerns about unprecedented health crises.

Adaptation alone is not enough
The researchers note that adaptation measures—such as greening cities, improving insulation, and expanding access to air conditioning—can help mitigate some risks. Yet even under optimistic adaptation scenarios, the projected death toll remains substantial. The study concludes that without aggressive reductions in greenhouse gas emissions, public health measures alone cannot prevent millions of deaths.

A stark reminder of climate urgency
Professor Antonio Gasparrini, senior author and head of the Environment & Health Modelling Lab at LSHTM, emphasized that the findings debunk the idea that global warming might bring “beneficial” reductions in mortality. Instead, the study projects a 50% net increase in climate-related deaths by 2099 under current emission trends. He added that up to 70% of these fatalities could be avoided with immediate and decisive climate action.

This research aligns with previous evidence linking deadly heatwaves in Europe to climate change. In June 2025 alone, extreme heat contributed to over 2,300 deaths. The Nature Medicine findings highlight that unless emissions are drastically curtailed, Europe faces a staggering and preventable public health crisis, making climate change one of the century’s most urgent challenges.