Tokyo residents campaign for citywide tree-cover targets amid shrinking canopy

In response to a rapid decline in urban shade, Kaoru Morimoto and fellow resident Susumu Nirasawa have organized a community campaign in Nakano, measuring temperatures and urging officials to adopt a canopy-cover target. Their group, now about 30 strong, holds expert briefings and posts data on social media while petitioning ward meetings. A University of Tokyo analysis released in 2024 reported that central Tokyo's tree cover dropped from 9.2% in 2013 to 7.3% in 2022, a loss of 12 square kilometres, and highlighted that mature trees in private gardens are being removed as land is subdivided.

Experts note that shaded areas can be up to three degrees cooler and that trees also mitigate flooding and improve urban wellbeing. Tokyo's metropolitan government claims it is carefully pruning trees on streets with wide sidewalks to grow canopies, yet it has not set a citywide target. The campaign comes as Japan recorded almost 120 heat-related deaths and more than 73,000 emergency-care cases in the recent hot season, underscoring the public-health stakes of the canopy loss.