By 2050, it's estimated that 80 percent of the world's people will live in urban areas (currently, 60 percent do). The population will have increased to about 9.2 billion, much of it in the developing world [Source: New York Magazine]. Many experts contend that unless drastic measures are pursued, the world could face dramatic shortage in both food and arable land. Famine and ecological catastrophe are among the possible dire consequences.
Enter vertical farming -- farming in skyscrapers several dozen stories high. Dr. Dickson Despommier, a professor of public health and microbiology at Columbia University, developed the idea with contributions from his students. Dr. Despommier claims that vertical farms could do more than just solve future food shortages. They could also stave off global warming, raise standards of living in the developing world and change how we get our food and dispose of waste. It may sound far fetched, but vertical farming is actually a very real possibility for the future.
The key to vertical farming is space. The Vertical Farm Project, led by Dr. Despommier, claims that one indoor acre of farming is equal to 4 to 6 outdoor acres [Source: The Vertical Farm Project]. They cite a farm in Florida that was converted into an indoor hydroponic farm where strawberries grow in stacks. That farm now grows the equivalent of 30 acres of strawberries in a one-acre greenhouse.
By converting from "horizontal farming" to vertical farming, humanity would never have to worry about running out of arable land. By operating indoors, crops could be grown all year, free of concerns about bad weather, drought or natural disasters. If the building is sealed and carefully monitored, there would be no need for pesticides to eliminate invasive insects or parasites, a particularly devastating problem in the developing world. All food would be organically grown without fertilizer and free of disease. Vertical farmers wouldn't have to worry about conflicts over land, water and other natural resources or contend with genetically modified foods, unwanted strains of plants or wandering animals.
These farms would also be located in the urban areas where most of the Earth's population will be living. The result is that agriculture becomes more of a closed system -- food is grown, transported, eaten and waste disposed of all in the same metropolitan area. In a major city like New York City, where almost all food must be flown or trucked in from miles away, the difference is tremendous. Vertical farming would largely eliminate the pollution generated as food is trucked, shipped and flown across countries to reach its desired markets.
Because vertical farms would exist in the communities they serve, crop selection could be altered to fit the local community. It's the culmination of an idea that's been gaining a lot of popularity lately and that's been chronicled in a host of books and articles: buying food from local farmers (within 100 miles or so of home) in order to support local growers and reduce one's ecological impact.
Finally, there's what might be the most enticing benefit: land that has been used for horizontal farming could become forests again. The result would be a major counterweight to global warming. Deforested areas could be returned to their natural states, replenishing plant and animal species, reducing CO2 in the atmosphere and providing beautiful park and woodland spaces for recreation and tourism.
The possible benefits of vertical farming are clearly numerous and dramatic, but what would a vertical farm look like, and would it work? Let's take a look on the next page.
Vertical Farm Designs and Challenges
Most vertical farm designs depict them as ultra-modern, stylish skyscrapers, 30 to 40 stories tall. Each floor could potentially feature a variety of crops and small livestock. Tanks would house fish and other seafood. Using technology to minimize waste and energy use, and to facilitate recycling, is essential. To that end, they would contain glass walls, large solar panels, high-tech irrigation systems and incinerators that burn waste for energy. A variety of monitoring systems would ensure that energy and water go where they need to go and that temperature controls are carefully maintained.
Water would be carefully distributed through irrigation while any excess water would be collected and recycled. Dew can be collected through evaporation. Sewage, also known as "black water," can be cleaned by algae and plants and made potable. Or it can be treated by filters and made into "gray water," which is sterile and useable for irrigation. Cities dump billions of gallons of gray water into rivers every day.
Methane gas, instead of being allowed to escape into the atmosphere, would be collected. Any excess energy would be sold back to the local energy grid.
Dr. Despommier believes that 150 30-story farms could feed all of New York City. Elegantly designed, these vertical farms would be carefully placed around a city or clustered together in a nearby development (in the case of New York City, possibly on Governor's Island). They would remain unobtrusive, or even pleasant to the eye.
For vertical farming to be possible, experts from a variety of disciplines have to come together, including agriculture, agronomy, civil planning, architecture, engineering, economics and public health. But we're not starting from scratch. Dr. Despommier and others have published studies describing plans for development and implementation of vertical farms. In fact, all of the technology behind vertical farming already exists, though it could take up to 10 years to figure out how to make these technologies work together. Even so, we already grow plants hydroponically (without soil), in extreme environments and on space ships. Biomass, methane collection and waste-water collection are becoming essential tools of conservation.
Some criticize vertical farming because it would eliminate jobs of conventional farmers and those who transport and package their goods. To those critics, one could point out that 95 percent of Americans were farmers before the Industrial Revolution, and this may simply be the next step in that evolution. But it's also the contention of Dr. Despommier that vertical farming would create jobs. Thousands of people would be required to develop, build and maintain these systems. The socioeconomic impact could be immense, especially for those who struggle as subsistence farmers or in abject poverty. In the developing world, the presence of a dependable food supply and improved nutrition would raise standards of living, allow the development of commerce and shift children away from agricultural work and into schools.
Two hurdles remain for vertical farming to become a reality: money and government support. However, Dr. Despommier is already in touch with investors and philanthropists who want to establish a Center for Urban Sustainable Agriculture. With enough investment, the first vertical farm could be up and running (and even profitable) in 15 years, while government support would surely help in their proliferation.
For more information about vertical farming and other related topics, and to watch a video showing a vertical farm design, please check out the links on the next page.
Related HowStuffWorks Articles
More Great Links
- Chamberlain, Lisa. "Skyfarming." New York Magazine. http://nymag.com/news/features/30020/
- Cooke, Jeremy. "Vertical farming in the big Apple." BBC News. June 19, 2007. http://news.bbc.co.uk/2/hi/americas/6752795.stm
- "Professor sees vertical farms on horizon." Knight Ridder Newspapers. Columbia Daily Tribune. Aug. 30, 2005. http://www.columbiatribune.com/2005/Aug/20050830Busi010.asp
- "The Vertical Farm Project." http://www.verticalfarm.com/
- "Farm of the Future?" U.S. News & World Report. May 28, 2007. http://www.verticalfarm.com/images/news/usnews-article.jpg