CNRS Ecologist Warns of Severe Damage from Extreme Heat

Paris – 13 July 2026: Ecologist Philippe Grandcolas is warning of severe damage to natural habitats in view of the ongoing extreme heat in France. The deputy scientific director of CNRS Ecology and Environment sees early signs of an ecological threat that extends beyond the immediate risks to human health. His assessment follows weeks of exceptional heat and drought across the country.

Météo-France classified June 2026 as the warmest June since nationwide records began. According to the agency, the average temperature was 3.8 degrees above the 1991 to 2020 reference level. From 17 to 30 June, France experienced an early, prolonged and particularly intense heatwave. At the beginning of July, very high temperatures continued locally, especially in the southeast.

At the same time, the weather agency recorded a nationwide rainfall deficit of nearly 50 percent in June. By the end of the month, soils across all of France, including Corsica, were affected by drought. This combination intensifies pressure on vegetation and water reserves. It also raises the risk of vegetation and forest fires, as plant cover and soils dry out more quickly.

Grandcolas points to the consequences for the overall interaction of natural systems. High temperatures can shift the development cycles of plants and animals, hinder reproduction and reduce the availability of water and food. Species that require cool or humid refuges and cannot quickly relocate to more suitable areas are particularly vulnerable.

The scientist does not view the effects of heat as an isolated summer problem. Damaged soils more readily lose their ability to retain water and nutrients during prolonged drought. This can place additional strain on agriculture, forests and waterways. When habitats are fragmented or weakened, many species also have fewer opportunities to adapt to changing conditions.

According to Météo-France, the frequency and intensity of heatwaves in France have increased significantly as a result of climate change. While such events occurred on average about once every five summers before 1989, they have been observed annually on average since 2000. The current situation therefore underscores the importance of long-term protection measures for water, soils and biodiversity.

For Grandcolas, the focus is not solely on protecting individual species. Intact ecosystems ensure pollination, soil fertility, water retention and the regulation of local temperatures. Their loss can therefore also have social and economic consequences. The CNRS ecologist’s warning draws attention to damage that develops during a heatwave and may only become visible over the course of years.