Trees are nature’s air conditioning, lowering city temperatures

New research from Delft University of Technology has found that trees work as nature’s air conditioners in cities, providing not only shade but also absorbing heat and reflecting sunlight.

The i-Tree 2.0 NL research project looked at how much “cooling performance”  urban tree species provide to Dutch cities.

“We now have a clearer picture of how different types of trees contribute to cooling. This helps to design urban environments more carefully with an eye for the changing climate,” head researcher René van de Velde told De Telegraaf.

Van de Velde looked at 69 different types of trees in Amsterdam, Rotterdam and Groningen.

The project found that, on hot days, when the temperature in the full sun can exceed 50°, the temperature under a tree can be up to 30° lower.

Beyond shade, trees provide a myriad of cooling benefits. They evaporate water during photosynthesis, which can cool the ambient air by an average of 2.6°. In addition, they influence the airflow between buildings, which can reduce the heat even further.

The researchers hope their work will help urban designers better able design and shape cities for climate adaptation.

The scientists aren’t the only ones who have been championing trees in the Netherlands.

During the Nato summit in The Hague on Wednesday, US president Donald Trump was also praising Dutch flora. “I saw the most beautiful trees,” Trump said during his address after meeting with world leaders. “In fact, I want to bring some back with me.”