This story ran in the June 2016 issue of National Geographic magazine.
Rooftop farms have sprung up so quickly in American cities over the past decade that even the USDA doesn’t know how many exist. Several can be found in New York City, providing local communities access to fresh produce. In some cases (like Brooklyn’s Eagle Street Rooftop Farm), the farms also offer educational and volunteer opportunities for people itching to flex their green thumbs.
The question of how to grow more food efficiently in metropolitan areas has gained urgency as urban populations rise: The UN Food and Agriculture Organization estimates that by 2025, 3.5 billion people will live in cities. But to increase yields in cities (as elsewhere), farmers must contend with climate change’s effects on growing conditions.
One potential solution: more innovative designs. For ecologist Dickson Despommier that means vertical farming, cultivating fruits and vegetables under controlled settings within tall buildings—now particularly popular in Japan. Architect Mitchell Joachim’s solution takes a different shape: The spherical pod he developed has a food-growing system on the outside and habitable space inside. The pod can be sized up to fit a larger site, Joachim says, or down to fit a high-rise balcony.