Vertical farming is a concept that argues that it is economically and environmentally viable to cultivate plant or animal life within skyscrapers, or on vertically inclined surfaces. The idea of a vertical farm has existed at least since the early 1950s and built precedents are well documented by John Hix in his canonical text "The Glass House."
Growing crops in a controlled environment has benefits: no animals to transfer disease through untreated waste; no massive crop failures as a result of weather-related disasters; less likelihood of genetically modified “rogue” strains entering the “natural” plant world. All food could be grown organically, without herbicides, pesticides, or fertilizers, eliminating agricultural runoff. And 80 percent of the world’s population will be living in urban areas by 2050. Cities already have the density and infrastructure needed to support vertical farms, and super-green skyscrapers could supply not just food but energy, creating a truly self-sustaining environment.
Dr. Despommier’s pet project is the “vertical farm,” a concept he created in 1999 with graduate students in his class on medical ecology, the study of how the environment and human health interact.
Critics point out that the cost of land in Manhattan would cancel out savings in food transportation costs, and the shortage of land in the city may make the project prohibitively expensive.
[Despommier] said that year-round crop production, no weather-related crop failures and no agricultural run-off as well as the possibility of freeing up land for ecosystem restoration are worthy reasons to build vertical farms, although he concedes that it will be an expensive and research-intensive effort to get off the ground, a sentiment that’s shared by green roof critics.
Most urban farming efforts have been small-scale experiments run in neighborhood parks. Despommier’s vision is bigger: a $200-million, 30-story tower covering an entire city block, stuffed with enough fruit, vegetables and chickens to feed 50,000 people. “With waste in and food out, a vertical farm would be like a perpetual-motion machine that feeds a lot of people,” he says. Most of the technology already exists, he adds, and with some refining, the project could be up and running quickly if granted 0.25 percent of the subsidies paid to American farmers in the past decade—a piddling $500 million.
Farmers already score per-acre yields using hydroponic tactics that are 30 times as high as those produced by traditional farming. In a vertical farm, nutrient-delivery machinery and 24-hour light exposure would improve on that yield many times over.
Studies have shown that proximity to parks and other greenways has a positive effect on property values. Properties adjoining green areas have market values up to 32 percent higher than similar properties 3,200 feet away, according to a 1979 study by Correll, Lilldalh and Singell of Boulder, Colo.
Despite its potential problems, the idea of bringing food closer to the city is gaining traction among pragmatists and dreamers alike. A smaller-scale design of a vertical farm for downtown Seattle won a regional green building contest in 2007 and has piqued the interest of officials in Portland, Ore. The building, a Center for Urban Agriculture designed by architects at Mithun, would supply about a third of the food needed for the 400 people who would live there.
Dr. Despommier estimates that it would cost $20 million to $30 million to make a prototype of a vertical farm, but hundreds of millions to build one of the 30-story towers that he suggests could feed 50,000 people.
Depending on the crops being grown, a single vertical farm could allow thousands of farmland acres to be permanently reforested. For the moment, these calculations remain highly speculative, but a real-life example offers a clue: After a strawberry farm in Florida was wiped out by Hurricane Andrew, the owners built a hydroponic farm. By growing strawberries indoors and stacking layers on top of each other, they now produce on one acre of land what used to require 30 acres.