PARIS, Aug 17 — After the heat wave brought by the Lucifer anticyclone in Europe, multiple solutions for countering these extreme phenomena linked to climate change and reduce the temperature in city centres are being highlighted. Here are three.

The city of Syracuse in Sicily recorded a peak temperature of 48.8°C on Thursday, 12 August, a historic heat record caused by the Lucifer anticyclone. This new heatwave represents an umpteenth challenge for the cities most affected by these increases in temperature.

So, how to bring down the mercury in these cities? How can we also create air currents and make life in these urban centres more pleasant? Faced with this overheating, there are several solutions.

Plants

Parks, trees, lawns, vegetated facades... Green zones refresh and absorb carbon emissions. The construction or redevelopment of spaces is the preferred solution to reduce heat islands.

In France, the city of Paris has 909 “cool” green spaces, not including cemetreies (17), which are considered “cool islands”. As the most densely populated city in France, it is all the more concerned by these heat waves.

Plans to create urban forests and plant trees are multiplying. In the United States, 60 billion new trees will be planted by 2040 according to the World Resources Institute.

In India, the various states are conducting tree planting campaigns across the country to cover a third of its surface. In early July 2021, more than 250 million saplings were planted in the state of Uttar Pradesh.

Urban planning

Some urban structures and features help create shaded areas or limit heat gain in buildings. The structures, according to their height and positioning, favour the creation of shade zones. Installed in areas without vegetation, they can be reliable creators of shade zones.

Placed on the roofs of buildings, solar panels absorb light. They provide a significant source of energy but also replace highly absorbant surfaces. Indeed, solar panels cool down more quickly during the night.

In the same logic of cooling surfaces, several cities have adopted reflective thermal paints. In the 20th arrondissement of Paris, the Louis Blanc school served as a test building in 2017 for the “Cool Roof.” The temperature in the classrooms on the top floor originally could reach 38°C.

According to the Climate Change association, one year later, the temperature during high-point hours never exceeded 28°C, dropping by 5°C on average. This technique is also applied on the roads, as has been the case since 2017 in Los Angeles.

During hot weather, cities can also install fountains and ephemeral water points in the streets.

The citizen

Among the solutions, citizens can take action to reduce city temperatures and live as well as possible during these episodes, first by reducing air conditioning as much as possible. Giving up the tickle of cool air on your face and ankles is hard to take, but producing cool air consumes energy and produces hot drafts.

So how do you give up that cool air? With natural air conditioning. In other words, create drafts by opening windows at night and closing shutters during the day to maintain the cooler temperatures reached during the night.

During the day, reduce road traffic by opting for public transportation. Choosing “soft” mobility reduces heat production. 

 - ETX Studio