Bleeding green: California's schools are rapidly losing tree canopy cover

For many students in California, schoolyards are often the only accessible green space in their daily lives. Maintaining and expanding schoolyard canopies is critical infrastructure for children’s health and resilience. As such, they represent a strategic site for both climate adaptation and environmental justice. We assessed changes in tree canopy cover between 2018 and 2022 across 7262 public urban schools using data from the CALFIRE Urban Tree Canopy Map. Our findings reveal that, at the state level, the mean net canopy change was –1.8 %, with 85 % of schools experiencing canopy loss during this period. However, the canopy decline was particularly acute in some districts, exceeding 25 %. Central Valley emerged as the most dynamic region, exhibiting both pronounced losses and gains. These trends reflect the combined effects of redevelopment, environmental pressures, and uneven greening efforts. Overall, the decline in canopy cover is particularly troubling as climate change intensifies extreme heat and drought conditions. Our findings underscore the urgency of targeted investments to protect California’s students and improve tree canopy in their school environments.