Overview

• Rapid attribution analysis of 854 cities estimates 24,400 heat deaths between June and August, with 68%—about 16,500—driven by human-induced warming.
• Cities were on average 2.2C hotter because of climate change, with local increases up to 3.6C, magnifying mortality risk during multiple heatwaves.
• The study covers roughly 30% of Europe’s population and highlights likely undercounting, since heat is rarely listed on death certificates and official data lag.
• Italy and Spain saw the highest climate-linked tolls (4,597 and 2,841 respectively), with major city estimates including Rome 835, Athens 630, Paris 409, Madrid 387, and 1,147 across the UK (315 in London).
• Older people bore the brunt—85% of excess deaths were in those 65+, 41% over 85—while separate Nature research tied many historical heatwaves to emissions from major fossil-fuel and cement producers, informing accountability debates.