Cities bound, bounded, boundless: urban metabolic entanglements and planetary boundaries

In this paper, I reflect on cities as metabolically entangled with the planet in the context of planetary boundaries. Reviewing a multi-disciplinary literature (urban metabolism, planetary urbanisation, Earth system boundaries), I conceptualise cities as simultaneously ‘bound’, ‘bounded’ and ‘boundless’ vis-à-vis the planet. Inspired by Tim Ingold’s notions of entanglement and ‘bindings against boundaries’, I offer metabolic entanglements as an entry point to explore urban-planet interrelations. I then present conceptual and methodological reflections on how to follow urban metabolic entanglements – incorporating footprints and flows, infrastructures and nexuses, ports and corridors, chains and corporations, political conflicts and geopolitical competition, ecological systems and environmental pressures – all the way to where they reach planetary boundaries, and back to ‘re-bounded’ cities.