Human-induced climate change made the fire weather behind July’s severe wildfires about 20 times more likely in central Spain and twice as likely in south-west France, according to World Weather Attribution.
Wildfires burned around 140,000 hectares in Spain between July 13 and 28, while 115,000 hectares have burned in France since the start of the year.
Three people have died and about 300,000 people have been forced to flee their homes across the two countries, according to the analysis.
Rapid vegetation growth earlier in the year, followed by extreme heat and drought, created highly flammable conditions.
Fire weather conditions behind July’s severe wildfires were made about twice as likely in south-west France and 20 times more likely in central Spain by human-induced warming and consequent climate change, according to a new analysis by World Weather Attribution (WWA).
The affected regions saw rapid vegetation growth at the start of the year, followed by months of extreme heat and drought. This combination created the perfect conditions for wildfires to ignite and spread.
World Weather Attribution, an international group of scientists that studies the role of climate change in extreme weather events, has previously linked the region’s unusually high June temperatures and ongoing drought to human-caused warming.
In Spain, the wildfires mainly affected Ávila, Madrid and Toledo in central Spain, Guadalajara to the north-east of Madrid, and Castellón in eastern Spain. The Ávila fire burned through 44,000 hectares, making it the largest and most destructive wildfire in Spain’s history, according to Spain’s Minister of the Interior, Fernando Grande-Marlaska, cited by WWA.
In France, the wildfires began along the Atlantic coast around July 22 and 23 before spreading inland. They became most severe in the Gironde department around Bordeaux. The Gironde fire burned 40,000 hectares, the second-largest area burned by a single fire in France since the Second World War, according to WWA researchers.
Between July 13 and 28, wildfires in Spain burned around 140,000 hectares. In France, 115,000 hectares have burned since the beginning of the year. Three people have died and about 300,000 people have been forced to flee their homes across the two countries, according to WWA.
The most severe fires are currently affecting central and eastern Spain and south-western France.
The researchers studied historical observations of weather conditions that contribute to wildfire risk and analysed how those conditions have changed over time. They used a metric called the Daily Severity Rating, or DSR, which incorporates hot, dry and windy conditions and reflects how difficult a fire is to suppress once it has started”, according to a press release from WWA. The measure reflects how difficult a fire is to suppress once it has started.
The study looked at the seven-day period when DSR was highest across the fire-affected regions of south-western France and central Spain.
In today’s climate, which is about 1.4 degrees Celsius warmer than the pre-industrial period of 1850-1900, such wildfire conditions are expected to occur about once every 20 years in south-west France and once every six years in central Spain, WWA said.
The analysis found that climate change made the fire weather conditions twice as likely in south-west France and 20 times as likely in central Spain.
“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, research associate in extreme weather and climate change at the Centre for Environmental Policy, Imperial College London, in a press release.
“A wet winter, followed by this intensely dry summer and a succession of heatwaves, has left forests loaded with dry fuel, and relentless heat — fuelled by human-caused climate change — has created the conditions for sparks to take hold and become massive, dangerous wildfires,” she said.
Barnes said climate change was repeatedly increasing hot, dry and flammable conditions that are highly conducive to wildfires. “What’s unique about this case is that it’s still early in the season, and with another heatwave looming, these findings are extremely scary,” she said.
Europe’s climate was changing faster than governments were adapting, Friederike Otto, professor of climate science at the Centre for Environmental Policy, Imperial College London, said. “Last year we documented the Iberian fires; more recently, our research showed how climate change is worsening drought across the continent. Now we’re seeing yet another disaster fuelled by the same driver: the burning of fossil fuels,” she said.
The findings underlined the need to strengthen both wildfire prevention and emergency response. “As the conditions that fuel severe wildfires, such as extreme heat and drought, become more frequent and intense, we must accelerate implementation of fire adaptation and prevention efforts while also deepening investments in fire response capacity,” said Julie Arrighi, director of programmes at the Red Cross Red Crescent Climate Centre.