This study investigates the effectiveness of urban trees in mitigating urban heat in various European climates. Using high-resolution satellite data from 293 European cities, the researchers compared land surface temperatures (LSTs) of urban trees, treeless urban green spaces, and urban fabric. Results show that urban trees exhibit lower LSTs than urban fabric across most of Europe, particularly in Central Europe (8-12 K lower), with a less pronounced effect in Southern Europe (0-4 K lower). Treeless green spaces were significantly less effective. The cooling effect of trees varied regionally and seasonally, decreasing during hot extremes in Southern Europe but remaining consistent or even increasing in Northern Europe. The study highlights the climate-dependent effectiveness of urban heat mitigation strategies.

Jonas Schwaab, Ronny Meier, Gianluca Mussetti, Sonia Seneviratne, Christine Bürgi, Edouard L. Davin