Vertical Farming is a concept designed by Dickson Despommier that argues for a conversion to large-scale urban farming by claiming that one 30-story structure with an area the size of a typical city block could produce as much food as 9.7 square kilometers of typical outdoor farmland.
The US harvests from 1.2 million square kilometers of agricultural land each year. That is roughly 3,800 square meters (about 1 acre) per US American. The average American meal travels over 2,400 kilometers from farm to plate. The distance food travels is responsible for the spoilage of nearly 30% of American produce.
About 82% of Americans live in urban areas. It is estimated that one, 30-story vertical farm could sustain 50,000 people per year. To feed all urban Americans, the US would have to build 5,084 of Despommier’s vertical farms. At an estimated cost of over $100 million per farm, feeding US America’s urban population purely off of vertical farms would require an initial investment of over $500 billion, $1,613 per urban US American.
The American agriculture industry consumes over 100 billion liters, roughly 20%, of all diesel and gasoline consumed in the US. At about $1 per liter, agriculture spends nearly $100 billion per year on fuel for transportation, fertilization and pest control. By theoretically eliminating the need for petroleum-based pesticides, herbicides and fertilizers, and by significantly lowering transportation distances, saved petroleum costs could pay for the construction of all 5,084 vertical farms over 5 years.
Agriculture consumes 70% of our planet’s available freshwater. Municipally-owned water treatment plants in the US treat roughly 132 billion liters of wastewater per day. Whereas most farms lose the majority of water through imperfect irrigation, a self-contained vertical farm could recycle close to 100% of water used in aeroponic and hydroponic agriculture.
New York City’s people produce nearly 4 billion liters of wastewater every day. It is theoretically possible to derive 100 million kilowatt-hours of electricity from New York’s solid waste alone – enough to power 4 of Despommier’s vertical farms.
Sources:
Despommier, Dickson. “The Rise of Vertical Farms.” Scientific American. November, 2009. (60-67).
http://www.scientificamerican.com/article.cfm?id=the-rise-of-vertical-farms
“Dickson Despommier’s Vertical Farms Feed Cities From Skyscrapers.” EarthSky. February 6th, 2009.
http://earthsky.org/food/feeding-future-cities-with-vertical-farms
“US Wastewater Treatment.” Center for Sustainable Systems. 2009.
http://css.snre.umich.edu/css_doc/CSS04-14.pdf