France's Hot Summer Could Cost Up to €15 Billion, or 0.5% of GDP, With Risks of Further Increases

Barbut said the preliminary estimate, which she advised treating with great caution, was based on an extrapolation of heat-related costs compiled by France's official statistics agency, Insee, in past years. She added that the figure could rise as temperatures remain well above seasonal averages in many French regions. Eighty-five percent of the country was under drought warnings as of mid-July.

Barbut said recent wildfires and drops in agricultural output were the biggest estimated costs and warned they would continue to grow if governments fail to implement policies to limit the impacts of climate change. France's August 2003 heatwave, which until this summer was the warmest ever recorded in the country, led to a 22 percent drop in cereal production and a 9 percent drop in wine production, according to Insee.