We live on an urban planet. In 2008, humanity passed a major milestone, with more than half of the world’s population living in urban areas for the first time in our history. And the planet will continue to urbanize in the decades ahead — by 2050, two out of every three people will live in an urban area, or roughly double the percentage of people who lived in cities in 1960. Nearly 40% of the projected urban growth between now and mid-century will take place in China, India, and Nigeria.
As our global population concentrates itself in cities, urban areas are becoming increasingly vulnerable from a food security standpoint. Some cities are already sitting on a knife’s edge with regard to food security, with comparatively small stockpiles of locally available food reserves in the event food shipments arriving by road, air, or sea are disrupted unexpectedly. For that reason and many more, urban agriculture has received increasing interest and investment in recent years as a means to improve urban food security.
As some cities work to source a greater amount of their food locally, what are the prospects for one especially ambitious form of urban agriculture — vertical farms — to boost food production in some of the developing world’s fastest growing cities? Can recent innovations and anticipated technological breakthroughs in vertical farming make it a practical approach to improving urban food security throughout the world? Or are some cities better positioned to benefit than others?
Let there be light
Vertical farming compares favorably to traditional agriculture because of its highly efficient use of soil and water resources, limited reliance on fertilizers and pesticides, and ability to reduce food waste by significantly decreasing the distance and time needed for food to reach consumers in urban markets. By growing upward and not outward, vertical farms also represent spatially efficient solutions for urban food production — but therein lies one of the technology’s biggest issues to date.
Unlike traditional single-floor greenhouses where sunlight can penetrate through the walls and the roof to stimulate plant growth, most vertical farms are more akin to apartment buildings, with many ‘floors’ of plants stacked on top of one another. As a result, critics say, only plants located near windows or the roof receive sufficient natural sunlight to stimulate vigorous growth, while the majority of plants are blocked from receiving direct light. Attempted solutions for this problem — such as indoor lighting, or conveyer belts that rotate plants into direct sunlight to ensure even growth — have been criticized for using far too much energy, calling into question vertical farms’ future as an environmentally sustainable food-production model.
But many leading experts who recently spoke with the Agriculture and Ecosystems Blog say a game-changing solution is on the way in the form of LED (light emitting diode) lighting. “If we are using something like LEDs, which are really energy efficient…. there is not much difference in energy consumption between growing crops in a field and growing them in a city,” contends Nate Storey, an aquaponics expert with Bright Agrotech in the U.S. state of Wyoming. Practitioners are confident LED lighting will change the face of vertical farming in the coming years, significantly reducing its energy footprint while enabling higher indoor crop yields.
Who will benefit?
Just because a potentially promising energy solution has been identified does not mean vertical farming will soon become a cheap undertaking, however. “Like any business,” says vertical farming specialist Grahame Dunling, “the highest costs are the start-up costs of the infrastructure,” including the “real estate that has to be purchased or leased.”
These high financial barriers to entry — not to mention subsequent costs for personnel training and infrastructure maintenance — have led some experts to question whether vertical farming will take root in cash-poor countries of the developing world anytime soon. “The big question is whether that investment is worth it, and how we are going to reduce the cost of that initial investment,” admits Storey.
But while high costs may mean vertical farming is not a good near-term solution for boosting food production in cities of the developing world, new opportunities for implementation may arise as the technology matures. “As vertical farming evolves,” predicts Columbia University ecologist Dickson Despommier and a leading global expert on vertical farming, “I am confident that cheap, reliable, highly productive versions of vertical farms will be invented to serve everyone who wants one.”
Going forward, what steps might municipal or national governments take to incentivize private investment in vertical farming in the developing world? Or might investments in urban food production in sprawling megacities be more effective if instead targeted toward other forms of urban agriculture with lower start-up costs?
Regardless of the specific path chosen, promoting local food production in the world’s fastest growing urban areas makes intuitive sense. With more city residents in the world than ever before, any steps we can take now to enhance urban food security and make more productive use of our urban spaces deserve serious consideration from policymakers and urban planners alike.