France and Spain wildfires burn nearly 300,000 acres as heat wave nears

The France and Spain wildfires have burned almost 294,000 acres across the two countries and forced nearly 300,000 people to leave affected areas, as officials and fire specialists warn that a new heat wave could intensify the emergency. The fires have destroyed nearly 104,000 acres in France and around 190,000 acres in Spain, according to figures reported by CNBC.

In southwestern France, the fires began last Wednesday in Gironde, a department on the Atlantic coast. Gironde’s prefecture said conditions were stable overnight, according to regional broadcaster France 3 Aquitaine, which also reported that 93 firefighters had been injured.

“The night was calm,” the prefecture said, according to France 3 Aquitaine. “The fire is still under control this morning.”

Even with that stabilization, crews remain under pressure as hotter weather approaches. Météo-France forecast temperatures of 33 to 35 degrees Celsius in France, with the heat wave expected to affect both France and Spain for the rest of the week.

How could the heat wave affect the France and Spain wildfires?

Higher temperatures can dry vegetation and make burning areas harder to contain, raising concern that fires already stretching emergency services could become more volatile. Nicolas Braz, a firefighter captain, told AFP that the fires are a rare and dangerous “pyrocumulonimbus” event, a fire cloud that can create its own thunderstorms, winds and whirlwinds.

That weather system can alter fire behavior quickly, making suppression more difficult for crews on the ground. Braz described the resulting behavior as “erratic and unmanageable,” according to AFP.

Stefan Doerr, a professor of wildland fire science at Swansea University, told CNBC’s “Squawk Box Europe” that wildfires are not unusual in the region, but said the three heat waves seen across the area this summer were unprecedented. “The overall scale of the events now is beyond the capability of dealing with it effectively,” he said.

The fires are also creating an economic shock for affected communities. French Finance Minister Roland Lescure told reporters the crisis was a blow to the local economy, saying: “It’s like a clap of thunder for an area which could have done without this.”

Georg Zachmann, a senior fellow at Bruegel who specializes in energy and climate policy, told CNBC’s “Squawk Box Europe” that the costs can be severe for regions paying for evacuations, firefighting and later infrastructure repairs.

“And even at the country level, we will see it in the fiscal budget of the countries,” Zachmann said. He pointed to the 2025 fires in California as an example of the fiscal scale, saying direct costs may have reached $40 billion to $60 billion, with indirect costs estimated at about $300 billion.

For France and Spain, the near-term test is whether containment efforts can hold as temperatures rise. Officials in Gironde have reported calmer conditions, but firefighters and climate specialists cited by AFP and CNBC say the combination of dry terrain, heat and fire-generated weather remains a serious risk.

This story draws on original reporting from CNBC.