A third of Ile-de-France residents considered very vulnerable to the heat wave, according to a study

Nearly a third of Ile-de-France residents, or 3.7 million people, are considered very vulnerable to high heat due to the urban areas where they live, other social parameters (age, income), according to a study released on Wednesday 19 July to Agence France-Presse (AFP).

Among these people, who represent 31% of the most populated region of France, the Paris Region Institute (IPR) lists 845,000 “sensitive” because of their age (under 5 or over 65). More than six million Ile-de-France residents, or half of the region, “reside[nt] in a block of houses with a potentially medium to high urban heat island effect (ICU) at night during the summer period”, estimates the IPR which compiled data from 2022, adding weighting elements from the 2003 heat wave.

The further you go towards the center of the Paris metropolitan area, the higher this proportion rises: from 21% in the outer suburbs, to 63% in the inner suburbs and up to… 99% in intramural Paris. But “it’s not 99% of the Parisian population who are vulnerable, you have to look at the other parameters”, explains to AFP Erwan Cordeau, climate specialist at the IPR.

To define the most exposed neighborhoods, the author of the study therefore took into account three vulnerability criteria: the UHI, but also “the exposure and sensitivity of goods and people to urban heat” (age , air pollution) and “difficulty coping” (income, access to health system and green spaces).

Municipalities of Seine-Saint-Denis more exposed

On this last criterion, the capital is almost free of red zones, unlike a vast triangle to the north of Paris between Aubervilliers, Saint-Denis and Le Bourget, the most exposed part of Seine-Saint-Denis.

If the older west of Paris concentrates more critical islands than the more popular and younger northeast of the capital, the study does not take into account “which population, mainly low-income, remains stuck in the summer and don’t go on vacation,” says Cordeau.

“The city doesn’t have the same socio-demographics at these extreme critical times,” Cordeau said.

Ile-de-France is relatively spared from the current heat wave raging in Europe, where the warming is, according to experts, twice as fast as the world average.