'Unchartered territory': Scientific community unsure if 'change of climate has become irreversible' More than 5,000 people died in France as a result of searing summer heat last year, health authorities said Thursday. "Everyone has been affected," Caroline Semaille, head of France's public health agency, told reporters as she presented a report on heat-related deaths last year. The summer of 2023, marked by four heatwaves including in August and September, was the fourth hottest on record in France. The year 2023 was also the hottest year on record globally. According to France's public health agency, 5,167 deaths -- or three out of every 100 fatalities -- were attributable to heat last summer. Of the deaths, around 3,700 were aged over 75. The extreme heat has been straining healthcare systems, hitting older people, infants and children. As scientists warn that climate change is posing an existential threat to life on Earth, FRANCE 24's Nadia Massih is joined by Vincent-Henri Peuch, Head of the Copernicus Atmosphere Monitoring Service (CAMS) and Deputy Director of the Copernicus Department at ECMWF.