After growing for several decades, among others because of the shift from agriculture to woodland, France’s forest carbon sink has been drying up since the 2010s due to increased tree mortality (droughts, fires, diseases, increased harvesting) and a slowdown in tree growth. By way of comparison, in 2020 French forests absorbed half of what they did in 2008. This phenomenon, about which scientists have been sounding the alarm for years, is beginning to worry the public sphere.
Last June, the French Academy of Sciences published a report dealing with the threats to forest carbon sinks, put into perspective with the national low-carbon strategy (SNBC). The report calls for an urgent review of the strategy, as there is a risk that its objectives will not be met. It specifically criticizes the strategy’s « intensification » scenario, which targets a 70% increase in wood harvesting by 2035, which would have the effect of reducing the total carbon sink in the years to come, due to emissions linked to harvesting and processing, even if the substitution effect is taken into account.
The Institut Économique pour le Climat and the Fern and Canopée associations had already raised this risk of intensifying wood harvesting. A poor estimate of the forest carbon sink can lead to errors in political choices. The French Academy of Sciences also highlights the impact of clear-cutting on the carbon sink and recommends continuous cover forestry, stand densities adjusted to water conditions, taking into account the fire resistance of tree species, and advocating long-lasting products.