Choice as the scarcest resource: Urban vegetation, structural trade-offs, and environmental justice in Japan's metropolitan areas

Urban vegetation is critical for well-being, but its equitable distribution remains a global challenge. The issue is particularly severe in high density metropolitan areas, where intense development pressure often conflicts with urban vegetation provision. The study provides a contribution by investigating the social-spatial patterns of green inequity across five major Japanese metropolitan areas: Tokyo, Osaka, Nagoya, Fukuoka, and Sapporo. Using functionally defined urban boundaries and census data, we analyze vegetation provision (NDVI) and accessibility (shortest distance) against a series of socioeconomic indicators through spatial regression models and local indicators of spatial association (LISA). Our results reveal a dominant core-periphery spatial structure in all metropolitan areas, with green scarcity in urban centers and abundance in peripheral zones, intensity is amplified by metropolitan scale. Contrary to many conventional findings, inequity in Japan is less consistently associated with traditional vulnerability metrics and more strongly predicted by occupation and housing tenure. We identify a unique sorting mechanism that a resident’s environmental reality is powerfully shaped by their functional role in the urban economy and market driven logic of the urban development. These findings contribute to global environmental justice theory by demonstrating that in hyper-dense and developed contexts, spatial structure and economic function can be primary drivers of inequity, thus complementing existing models that are often centered on social vulnerability. We conclude that “choice” is the scarcest resource and argue that effective policy must integrate greening with housing and transportation to dismantle the punitive trade-offs that residents face.