Can New York survive–thrive, even–as a self-sufficient and green city-state, with all its food coming from farming towers and miniature greenhouses? It’s not something that’s ever going to completely happen, but knowing what is possible could lead us to healthier, more-sustainable choices. From an Aeon essay by Michael Sorkin of NYC (Steady) State, an organization that hopes to answer that question:

“New York is a city of foodies with a staggering profusion of cuisines, and it has bred an advanced discourse about nutrition, organisation, justice, technology, and culture. It abounds with community gardens, with increasingly large commercial farming, and other sites of production, from backyards to rooftops to the tofu-producing cellars of Chinatown, but also with a rich distributive infrastructure of food co‑ops, farmers’ markets, meals‑on‑wheels, soup kitchens, school cafeterias and restaurants. The question for us was: how can all of this be elaborated into more supple and comprehensive networks that take account of our transformed habits and desires? And, to what degree could this be scaled up to feed 8.5 million people?

We discovered that it is in fact technically feasible to produce 2,500 nutritious calories a day for everyone in the city. At one level, the required infrastructure is not entirely outlandish. It would depend on the widespread use of vertical farming, building over existing infrastructure – railways, highways, factories, etc – and the densification of some parts of the city currently built at suburban scale. The cost, however, would be prodigious and many of the implications highly vexed. For example, the energy required to light, heat, and build all of this is, we’ve calculated, approximately equivalent to the output of 25 nuclear power plants, an eventuality that is, to put it mildly, somewhat at odds with our larger intentions. Likewise, the necessarily industrialised character of such production would beg the question of resisting the tender mercies of agri-business and the huge variety of its downside effects.

But, by finding a series of ‘sweet spots’, or more nominally ‘practical’ scales for sustainable food production, we’ve sought to balance cost and benefit socially, environmentally, economically, and culturally. We’ve looked at window boxes; at using the subways for freight; at a scheme encompassing the territory with a 100-mile radius around the city; and at reusing the 19th-century Erie Canal for a statewide system. We’ve recaptured street space, designed skyscraper farms for plants and animals, and plotted how to integrate all this into the fabric of the existing city. And, we’ve sought to deepen the idea of the urban neighbourhood as the core unit of sustainable urban organisation.”