More than 5 million inhabitants potentially exposed to urban heat islands in France

This phenomenon is characterized by higher temperatures in the city than in the surrounding countryside, particularly at night and during heatwaves, with consequences for health.

According to Cerema, more than five million residents live in neighborhoods "highly sensitive to extreme heat" and more than 200 km2 of built-up areas, twice the surface area of ​​the City of Paris, are "highly or very sensitive to the heat island effect" and would require "significant adaptation actions."

In cities with more than 400.000 inhabitants, these areas represent "nearly 20% of the urbanized fabric" and two million people live in areas of "high or very high sensitivity", or 50% of the population.

The smaller the city, the smaller the number of people affected.

In towns with 20.000 to 50.000 inhabitants, only 7% of residents are exposed.

Cerema used very high spatial resolution satellite images and open databases to map local climate zones (LCZs) and identify neighborhoods particularly exposed to urban overheating.

In total, the 88 largest urban areas in France are covered, representing 44 million inhabitants in 12.000 municipalities.

Cerema offers local authorities a free pre-diagnosis service for assessing neighborhood sensitivity to the heat island phenomenon, as provided for in the National Climate Change Adaptation Plan. This tool allows urban areas to be classified according to their potential exposure, particularly in the context of urban renewal projects, the revision of an inter-municipal local urban plan, or the development of climate change adaptation plans.

According to Météo France, the five cities most exposed to this phenomenon are Paris, Grenoble, Lille, Clermont-Ferrand and Lyon.

Illustrative image of the article via Depositphotos.com.