Urban metabolism as a pathway to advance Nature-based Solutions for climate-resilient cities

Rapid urbanisation has stimulated profound socio-economic transformation while intensifying systemic urban risks such as flooding and urban heat. These climate-induced stresses underscore the imperative of resilience-oriented urban frameworks. Existing research highlights Nature-based Solutions (NbS) as pivotal strategies for climate mitigation and adaptation, yet their widespread implementation remains constrained by persistent barriers. Urban metabolism (UM) provides an analytical foundation to address these challenges by conceptualising cities as dynamic systems of material, energy, water, and waste flows. By reframing NbS through a metabolic lens, this review highlights how UM can (i) generate operationally verifiable performance indicators, (ii) expose hidden material and energy flows underpinning NbS, (iii) quantify trade-offs in cost and energy use, and (iv) support the system-level integration of NbS with grey and hybrid infrastructures. We conclude by identifying research priorities for linking metabolic diagnostics with resilience indicators and governance mechanisms, thereby advancing the construction of adaptive and resource-efficient resilient cities.