Stacked plants may need to be rotated to make the most of available sunlight, which can be supplemented (or even substituted altogether) with LED grow lights. These can be calibrated to provide blue and red light in optimal doses for each type of plant, and timed to increase plant growth with extended days and growing seasons. (While it’s technically possible to grow any type of crop this way, for now it’s mainly leafy greens and tomatoes that are economically viable.) Cool enough to be strung right in among the plants without burning them, LEDs reduce site electricity consumption (and costs) per square foot of grow area by about a third compared to older technologies, such as high-pressure sodium. “Energy is a game-changer,” says Dickson Despommier, an emeritus professor of microbiology and public health at Colum­bia University, whose seminal 2010 book, The Vertical Farm: Feeding the World in the 21st Century, is widely credited with kick-starting vertical agriculture in North America. Cost-effective LED lighting opens up the possibility of converting urban and urban-adjacent building types such as parking garages, big-box stores, and shopping malls into productive local farms, he says.

With productivity rates that are orders of magnitude greater than conventional farming, high-rise growing is gaining traction worldwide. The world’s first such system began operations in 2012 in Singapore. The land-strapped city-state, which imports about 90 percent of its food, aims to grow a third of its produce locally by 2030. Indoor vertical farms in the country now produce about 80 tons of greens a year, and the Singapore Food Agency is supporting research into and development of the method as its main bet on the future.

In China, great swaths of arable land have been lost to development (more than 30 million acres between 1997 and 2008) and 20 percent of what’s left is contaminated. At the same time, the country has a strong tradition of urban-adjacent farming. When a 247-acre agricultural site, midway between Shanghai’s main international airport and the megacity’s center, recently came up for redevelopment, global design firm Sasaki proposed that, rather than create yet another tech park, the client take its agricultural mission to the next level. As a result, the Sunqiao Urban Agricul­tural District is slated to become one of China’s first comprehensive national agricultural zones. Sasaki’s master plan, which has received approval from the Pudong District and is now proceeding for formal approval from the City of Shanghai, expands the district’s role in Shanghai’s food network, integrating vertical agricultural production, research, and education into a dynamic public domain. In addition to research and development facilities and an agriculture production zone, the plan provides for a civic plaza showcasing productive landscapes, a science museum, an interactive greenhouse, an aquaponics display, and a destination market. “It’s urban agriculture on steroids,” says Michael Grove, chair of landscape architecture, civil engineering, and ecology at Sasaki.

Grove identifies three primary drivers for prioritizing urban agriculture globally: the need to curtail agricultural sprawl and thereby protect ecosystems, to reclaim economic agency by diversifying control of food production, and to build community: “Food brings us together,” he says. Behind Asia’s early adoption of urban agriculture, he sees a historic understanding among the region’s societies that the well-being of the population requires systemic support. That may also be a factor in Europe, where the Netherlands is a global leader in controlled-environment technology, and Denmark is home to the world’s latest and largest vertical farm, a partnership between a Taiwanese CEA tech company and a local start-up: with growing shelves stacked 14 deep, the 75,000-square-foot wind-powered facility has the capacity to produce 1,000 metric tons of greens a year.

PHOTOGRAPHY: COURTESY VERTICAL HARVEST (OPPOSITE); © HANNAH HARDAWAY

VERTICAL HARVEST’S three-story CEA facility (top and bottom) in Jackson Hole, Wyoming, produces as much food on a tenth of an acre as on a 10-acre conventional farm.

North America has been slower to adopt vertical farming, a lag that Ohio State’s Kubota attributes in large part to the year-round, nationwide availability of produce from California, Arizona, and Florida. But now, she says, climate disruptions and shortages of viable farmland in those states, along with the increasing urbanization of the workforce, strengthen the rationale for controlled environment agriculture. To support Ohio State University’s multidisciplinary research into CEA, a one-acre vertical greenhouse is under construction within sight of downtown Columbus. As part of the facility, the recently completed Kunz-Brundige Franklin County Extension Office serves as a hub for teaching, research, and community engagement around food, health, agricultural production, and sustainability. Both buildings are designed by Philadelphia-based Erdy McHenry Architecture.