Climate justice: low-income households more exposed to heat islands in cities, according to a French study

Cities are warming up and the poorest are on the front line: working-class neighborhoods, generally dense and sparsely vegetated, are on average the most exposed to the heat island phenomenon, the French Institute of Statistics (Insee) revealed in a study on Wednesday, November 13.

Of the nine French metropolises, analyzed in detail using European satellite data, it is in Lyon, the third largest city in France, in the south-east, that the gap in exposure to heat islands according to standard of living is the most marked: in the summer of 2017, without a heatwave, it reached 0,41°C between the tenth of the wealthiest households and the tenth of the least wealthy, ahead of Nice, where this gap rose to 0,37°C.

These differences "are not necessarily significant in terms of public health but serve as an indicator for greater gaps during future heat waves," explains the institute, which mentions more pronounced gaps in cities than in the countryside.

The urban heat island effect, linked to concrete which stores heat during the day and re-radiates it at night, but also to car traffic and the release of hot air by air conditioning systems, can be tempered by green spaces and non-impermeable soils, which retain humidity.

But not everyone is on an equal footing when it comes to this risk.

Poor households "are more vulnerable to high temperatures, and have fewer options to cope with them: in particular, they less often have air conditioning or a second home," the institute assures.

In 2023, 55% of French people said they had suffered from the heat in their homes for at least 24 hours, a quarter suffered from it "frequently" during the summer, while the number of people living in "too hot" homes has increased by 26% since 2013, the Abbé Pierre Foundation revealed in a report in August.

At the end of 2022, the government launched the "Resilient Neighborhoods" program, with a budget of 250 million euros, to help 49 neighborhoods adapt to climate change by, for example, combating heat islands.

The City of Paris, which presented its fourth "climate plan" on Tuesday, plans to create a "cool island" less than seven minutes' walk from each resident.

Illustrative image of the article via Depositphotos.com.