Europe's death toll from weather disasters could rise 50-fold by the end of this century, with extreme heat alone killing more than 150,000 people a year by 2100 if nothing is done to curb the effects of climate change, scientists said.
In a study in The Lancet Planetary Health journal, the scientists said their findings showed climate change placing a rapidly increasing burden on society, with two in three people in Europe likely to be affected if greenhouse gas emissions and extreme weather events are not controlled.
The predictions, based on an assumption of no reduction in greenhouse gas emissions and no improvement in policies to reduce the impact of extreme climatic events, show European weather-related deaths rising from 3,000 a year between 1981 and 2010 to 152,000 a year between 2071 and 2100.
Swathes of southern and eastern Europe sweltered in temperatures above 40C yesterday in a heat wave nicknamed "Lucifer" that has fanned forest fires, triggered weather warning alerts and damaged crops.
Italy and the Balkans have been worst affected, though areas as far north as southern Poland also basked in abnormally hot temperatures, and European weather hub Meteo-alarm issued its highest grade 'red' warnings for 10 countries.
Firefighters busy in Serbia, Bosnia, Macedonia and Croatia, and authorities advised people to stay indoors and increase their water intake.
Temperatures are expected to stay around 40C for much of Europe into next week.
"Climate change is one of the biggest global threats to human health of the 21st century, and its peril to society will be increasingly connected to weather-driven hazards," said Giovanni Forzieri of the European Commission Joint Research Centre in Italy, who co-led the study.
He said that "unless global warming is curbed as a matter of urgency", some 350 million Europeans could be exposed to harmful climate extremes on an annual basis by the end of the century.
The study analysed the effects of the seven most harmful types of weather-related disaster: heat waves, cold waves, wildfires, droughts, river and coastal floods and windstorms in the 28 countries of the European Union, plus Switzerland, Norway and Iceland.
The team looked at disaster records from 1981 to 2010 to estimate population vulnerability, then combined this with modelling of how climate change might progress and how populations might increase and migrate.
Their findings suggested heat waves would be the most lethal weather-related disaster and could cause 99% of all future weather-related deaths in Europe rising from 2,700 deaths a year between 1981 and 2010 to 151,500 deaths a year in 2071 to 2100.
The results also predicted a substantial rise in deaths from coastal flooding, from six deaths a year at the start of the century to 233 a year by the end of it.
The researchers said climate change would be the main driver, accounting for 90% of the risk, while population growth, migration and urbanisation would account for 10%.
Paul Wilkinson, a professor at the London School of Hygiene and Tropical Medicine who was not involved in the research, said its findings were worrying.
"Global warming could result in rapidly rising human impacts unless adequate adaptation measures are taken, with an especially steep rise in the mortality risks of extreme heat," he said.
The findings add "further weight to the powerful argument for accelerating mitigation actions" to limit emissions, slow climate change and protect population health, Professor Wilkinson said.