Translating planetary boundaries into city systems: Ecosystem services as metrics for safe and just production-consumption space

Accelerating urbanization has positioned cities as epicenters of water-energy-food (WEF) demand growth, yet their resource consumption patterns persistently exceed planetary boundaries. Resolving this dual challenge requires fundamentally rethinking cities' capacity to operate within ecological supply limits while ensuring basic human needs. We implement a city-scale adaptation of the doughnut framework, constructing a safe and just space (SJS) assessment model that quantifies ecosystem services (ESs) as linkages between WEF demands and ecological boundaries. Our analysis of 336 Chinese cities reveals spatial disparities: 91 % of cities in China can operate within their SJS for water provisioning, while only 25 % maintain current carbon emissions below ecological ceilings. Additionally, 28 % of cities simultaneously fulfill the SJS requirements for phosphorus purification. Regarding land use, 69 % can operate within the SJS, but most cities are approaching or already at verge of the biophysical boundary. In general, only 13 % of cities can adequately meet social demands within the boundaries of all four ESs. Random forest algorithm further identified social variables (e.g., population) and economic variables (e.g., industrial growth and gross regional domestic product) as dominant drivers of SJS performance. These findings underscore the imperative for adaptive governance that coordinates ES management through the SJS-ESs-WEF nexus, offering actionable pathways to align urban development with ecosystem stability and social justice imperatives.