A recent study led by UCLA associate professor of urban planning Kristen Schwarz highlights the lack of shade on California’s K‑12 school campuses, exposing students to extreme heat during outdoor activities. Analyzing over 7,200 urban public schoolyards from 2018 to 2022, the team found that 85% of schools lost tree canopy, with a median coverage of just 6.4%.

L.A. Times reports that many of these schools lack adequate tree cover and children, whose abilities to regulate body temperature are still developing, are particularly vulnerable when exposed to the intense heat outdoors. This presents a pressing concern as global temperatures continue to rise and give way to dangerous heat waves.

“Extreme heat is becoming a major public health concern in California and across the country, and trees can play a really big role in helping us cool down those schools and also build climate resilience,” said Schwarz.

To better understand the cooling effect of trees, Schwarz and her team are examining the trees and microclimates of schools across several districts in California. They hope their findings will inform policymakers and promote school greening to provide a cooler, safer environment for students in the face of global warming.