Humanity’s burning of fossil fuels directly led to the deaths of at least 1,500 people in a European heatwave last week, a landmark study said.

A blaze in southern France forced the closure of the Marseille airport, and weather agencies issued warnings for other parts of Europe where temperatures were expected to climb this week.

The first weeks of summer have been cruel for Europe with two heat waves leaving much of the continent under heat warnings. June was the hottest on record for western Europe.