France’s battle to contain ferocious wildfires in the southwestern Gironde region entered a second week on Tuesday, with more than 19,000 hectares of pine forest already reduced to ashes. While the ecological and economic damage is immense, some conservationists see the fires as an opportunity to adapt Europe’s largest artificial forest to the challenges of global warming.
French authorities have deployed much of the country’s fire-fighting capacity to curb fierce blazes that have raged since July 12, fuelled by swirling winds and a scorching heatwave.
More than 34,000 people have been forced from their homes and summer vacation spots in the Gironde region, with the flames moving to within a few kilometres of the famed Dune de Pilat, Europe's highest sand dune and a tourism hotspot.
The continent’s largest man-made woodland, the nearby Landes forest is caught in between two wildfires of exceptional intensity. One has consumed more than 6,500 hectares of vegetation near the Arcachon maritime basin famed for its oysters and beaches. The other has raged further inland, around the town of Landiras, torching some 12,000 hectares.
Between them, the two blazes have already consumed “more than half the surface area burned by fires, on average, each year across the country", said Dominique Morvan, an expert in wildfires at the University of Aix-Marseille.
‘Carbon bomb’
While the authorities’ first priority is to evacuate people and protect residential areas, experts are already assessing the ecological and economic cost of the devastating fires, which are set to profoundly impact biodiversity, soil quality and, potentially, weather patterns too.
Indeed, “while global warming explains why forest fires are more becoming more frequent and intense, such fires can in turn accelerate the rise in temperatures”, said Thomas Smith, an assistant professor at the London School of Economics (LSE) who has researched the impact of forest fires on climate.
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By consuming the Landes’ famed pine forests, the fires release vast quantities of CO2 stored in the trees. When thousands of hectares go up in smoke “it’s like a carbon bomb exploding”, said Jonathan Lenoir, a specialist in forest management at the CNRS research centre.
Such effects were widely documented following Australia’s historic wildfire season in 2019-2020, which triggered vast algal blooms in the Pacific Ocean and turned New Zealand’s glaciers brown with ash.
However, experts caution that the boom in emissions will be on a much smaller scale in France’s case.
“The surplus of carbon dioxide in the atmosphere will certainly have an impact, but it will not be quantifiable on the scale of all other greenhouse gas emissions,” said the CNRS’s Jean-Baptiste Filippi, a member of the forest fires research group at the University of Corsica.
A changing landscape
Another likely consequence of the fires raging in Gironde will be a shift in the type of vegetation, said Filippi, noting that the trees and bushes that are most suited to the changing climate also have the best chance of surviving blazes.
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The vegetation that grows back naturally is likely to be of a more Mediterranean type, Filippi added, resulting in a landscape similar to the scrubland of southeastern France, “which provides less cover, evaporates less water and therefore also produces less freshness”.
While the short-term outlook is bleak, the increasing fires present “an opportunity to improve forest management in the longer term”, argued LSE’s Smith.
Inevitably, the loss of thousands of pine trees will carry an economic cost for the many industries that rely on the Landes’ sprawling forest land. Covering one million hectares, the forest is vital to the paper, carpentry and chemical sectors and is also used by energy firms for the development of biomass.
“The economic cost will be calculated both in the number of trees lost and the impact on tourism,” said Morvan, noting that the Landes’ iconic pine trees have become a symbol of the region.
The loss of trees to wildfires will also leave the area exposed to other weather hazards, including flashfloods, he warned.
“When vegetation is abundant, rainwater is rapidly absorbed,” Morvan explained. “But when the earth is dry there is a risk of soil leaching, meaning that the water is not absorbed and washes away the soil.”
Replacing monoculture
While the short-term outlook is bleak, the increasing fires present “an opportunity to improve forest management in the longer term”, argued LSE’s Smith.
According to Lenoir, the fires raging in Gironde have exposed a key weakness of artificial pine forests, “a monoculture that was decided at a time (in the 1970s) when the issue of global warming was absent from debates”.
Forests with only one type of vegetation “are the ones where fire spreads fastest”, he added, describing the Landes forest as “a matchbox that was only waiting for the spark of global warming to catch fire”.
Lenoir is hoping the crisis in Gironde will help raise awareness of the need to introduce greater diversity in forests, mixing pines with more fire-resistant vegetation.
“We are now paying the price for the mistakes of forest management in Southwest France,” he said. “Starting again on a more resilient basis will mean promoting more heterogeneous vegetation, in some cases by letting the forest grow back naturally.”
This article was adapted from the original in French.
