Cooling efficacy of trees across cities is determined by background climate, urban morphology, and tree trait

This study examines how urban trees cool cities by analyzing 182 studies across 110 global cities. It explores how tree traits, urban design, and climate influence cooling, providing guidelines for urban planners to maximize tree benefits against heat stress and climate change.

The study finds trees can lower temperatures by up to 12°C through shading and evapotranspiration. Mixed-species plantings cool better in temperate and tropical climates, while evergreens work best in arid areas. Trees reduce extreme heat in 83% of cities, but dense canopies can trap heat in humid, enclosed spaces.