Faced with the plump heat waves, city dwellers are looking for spaces to cool off in urban areas. But allowing greenery to take root in the asphalt oceans that are the heat islands, it is not always obvious. A researcher from Harvard University created a temporary solution to quickly green concrete spaces, such as parking or public places.
When she realized that areas hard hit by the heat islets often hosted more vulnerable populations and low-income households, Belinda Tato, an associate professor of landscape architecture with Graduate School of Design from Harvard University, in the United States, felt that it was urgent that it takes advantage of its design skills to attack the problem. “Wealthy people can flee the heat – they have a swimming pool, a second home. But those who have nothing should be able to count on the city, ”she underlines.
His team therefore designed a prototype vegetated tower that is easily installed in spaces poor in vegetation so that people can come to refresh themselves. Their objective: that the temporary project is easy to adapt in other cities, with accessible, affordable, reusable and recyclable materials.
Thus was born the Polinature project, tested last summer by the researchers on the Harvard campus, near Boston. Disassembled since, the autonomous structure was made of scaffolding, air bubbles creating breezes, solar panels and more than 1,400 plants.
Photo Emilio P. Doiztua, provided by Belinda Tato
The team of a Harvard teacher has designed a prototype green tower that easily settles in spaces poor in vegetation so that people can cool off.
We had inserted climatic sensors into the project, and the data prove that we have managed to lower the temperature significantly in the shade of the structure.
Belinda Tato, associate professor of landscape architecture at the Graduate School of Design from Harvard University
“It is fascinating, because the investment is minimal, especially in comparison with large -scale projects that take years to be carried out – when they come true,” explains Belinda Tato.
The professor is not wrong: permanent projects to counter the heat islets can take time to emerge. In Montreal, for example, between 2013 and 2023, the area occupied by heat islands decreased by only 0.4 %.
Photo Emilio P. Doiztua, provided by Belinda Tato
Climatic sensors installed in the Polinature project
According to the organization to live in the city, at present, the disadvantaged sectors of the island have three times more heat islands than the others.
“Some areas may not have new parks before five or ten years. In addition to major infrastructure projects, it is therefore also necessary to find immediate, intermediary solutions, ”argues Belinda Tato.
A renewed experience
The researcher repeated the experience of a temporary structure this year, this time in the Chinese district of Boston. “This district has suffered from environmental racism and a lack of investment in green infrastructure. There are about 7 % vegetable coverage. It is therefore a very disadvantaged district in terms of climate comfort, probably the hottest of Boston, “she explains.
“Again, the idea is to see how we can alleviate extreme climatic conditions in places essentially covered with asphalt. We build a 15-meter-long table, with integrated benches and 17 trees-which are also beneficial for biodiversity and pollinators, ”she adds.
At the end of the project, plants will be redistributed. “Plants remain in the neighborhood and continue to attract pollinators the following year. It is beautiful to see them overwhelm, “she says, hoping that her project will do little ones all over the world.
Photo Emilio P. Doiztua, provided by Belinda Tato
Plants installed in the Polinature project
Arouse debate
Another objective of Mme Tato: Create a space for discussion in the shade of the plants. “Without climate comfort, people cannot end up in public space,” she said. “It is obvious for many of us, but there are still people who cut trees to put bitumen. »»
For Valérie Ebacher, urban planner and coordinator to live in town, one of the qualities of the Harvard project is precisely to attract eyes.
It is certain that this type of object can be interesting to bring the question of heat islets in public debate, to react, but it is certain that there must be more structuring long -term tools: it remains too partial as a strategy.
Valérie Ebacher, urban planner and coordinator to live in town
Mme Ebacher wants cities to adopt ambitious transformation plans to add greenery in the streets, parks and municipal grounds, but also to better supervise private spaces, where we find a good part of the concrete areas.
In this regard, Montreal wants to straighten the bar. By 2030, it wishes to reach 38 % of vegetation on its territory, by acting particularly in more economically vulnerable areas.
What is a heat island?
Heat islets are warmer urban areas than surrounding areas during similar weather conditions. The presence of waterproof surfaces such as concrete and asphalt, lack of vegetation and industrial activities create environments where heat is struggling to dissipate. During a heat wave, these hot spots pose significant health risks, especially because the surrounding temperature remains high even at night.
See the heat islet map in Montreal
