On the occasion of the COP 25, Europe 1 is looking throughout the week on solutions to be put in place in the future, to meet the challenges of global warming. Wednesday morning, our columnist Jean-Pierre Montanay tells how the UN plans to refresh cities by developing urban forests. A solution that particularly concerns Asia and Africa.
Baptized "A Great Green Wall for Cities", the project aims to create nearly 500,000 wooded hectares by 2030 and maintain 300,000 hectares of existing forests. These megalopolis forests like Kuala Lampur, Jakarta or Yangoon could dramatically reduce temperatures, with nearly eight degrees less. It also helped reduce air-conditioning costs by almost half, and improve water quality.
In Africa, priority will be given to poor neighborhoods often without vegetation: in Ethiopia and South Africa, the temperature differences with the posh areas with trees can reach 10 degrees. In China, 30% of the cities that will exist in 2050 have not yet come out of the ground, so the idea is to start planting trees right now before erecting the skyscrapers.
Ecological skyscraper
The goal is to emulate Singapore, an international model of a green city. Pioneering and innovative, it has become in a few decades the urban garden of Asia. It has the ambition to become the most vegetated city in the world in 2030. With its three million trees for nearly six million inhabitants, biodiversity is richer there than it was 20 years ago. The floor space is limited, vegetation climbs with the towers. For example, Capital Green is the city's first green skyscraper, with trees on every floor and a rooftop garden to capture CO2 and cool offices.
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Around the world, this type of initiative gives ideas. According to a study by the University of Zurich in 2050, Paris will be as hot as Canberra in Australia. In the summer, on average, the mercury will gain four degrees. Hence the decision, as of 2020, to plant 20,000 new trees in the capital, according to the strategy of urban refreshment. After concreting, it is now a question of de-bitumen and re-vegetation, to create islands of freshness.