cityplanet

Cityplanet is a term used in urban planning theory and science fiction to describe a city-scale settlement that occupies an entire planet or functions as a planetary-scale urban ecosystem. It is a speculative concept, proposed to address population density, resource scarcity, and climate risk by integrating architecture, infrastructure, and governance at a planetary magnitude.

Core design ideas include self-sufficiency, closed-loop cycles, and high-density, multi-layer habitats. Buildings and districts are arranged to optimize energy efficiency, with modular sectors that can expand or shrink. Energy relies on renewables—solar, geothermal, and possibly orbital generation. Transportation emphasizes high-capacity transit, automation, and streamlined logistics.

Governance and economy are depicted as integrated and data-driven. Decision-making may be centralized for swift action or distributed across planetary sectors. Economic models emphasize access and shared services, with formal resource accounting and robust maintenance and waste systems.

Infrastructure must manage planetary-scale utilities, climate control, and connectivity. Challenges include feasibility, planetary protection, political legitimacy, social equity, and enormous capital costs. Critics warn of centralization risks and governance complexity.

The concept remains speculative but informs discussions in speculative design and future studies, offering a framework to probe how dense, technologically advanced urban systems might function and the social, ethical, and ecological trade-offs involved.