The scientists had already found that climate change increased the likelihood of the record-breaking Western European heat wave in late June as well as the spring drought — both events that made land more fire-prone.
“These mega-fires show how fast climate-driven extreme heat and dry landscapes can turn wildfires into devastating national disasters,” said United Nations climate chief Simon Stiell in a statement responding to the findings.
“Humanity continuing to burn colossal amounts of coal, oil and gas is baking our planet, making these conditions more dangerous, and these megafires more deadly and destructive,” he added, calling for a faster transition from polluting fossil fuels to clean energy.
The researchers looked at a fire risk metric incorporating hot, dry and windy conditions, as well as landscape conditions during the worst fire week near Madrid and Bordeaux. They then compared this year’s situation to the worst conditions in previous summers and juxtaposed the current climate with a simulation of the planet’s pre-industrial state.
The study also established that in today’s climate, similar fire weather is expected to occur every 20 years in southwestern France and every six years in central Spain.
A key driver of the increased fire risk was weather whiplash earlier this year, with a dry spring following a wet winter, the scientists added. These conditions fueled excessive vegetation growth that then dried up, providing plenty of fuel for fires to spread.
“What we’re seeing in France and Spain isn’t just bad luck, it is a clear sign of the escalating impacts of anthropogenic warming,” said Clair Barnes, a climate scientist at Imperial College London and the lead researcher on the analysis.
“Every fraction of a degree of warming pushes us into unknown territory, and these fires show exactly what that risk looks like,” she added.