In “Urban Farming,” Crops Grow in Skyscrapers
Scientist Dickson Despommier has designed a scheme to grow crops inside 30-story skyscrapers. This urban farm concept could help feed a rapidly growing population, leave space for forests, and supply potable water for entire cities.
A look into the near future can be alarming: Currently, 40% of the land world-wide is being used for agriculture, to feed our current population of about 6 billion people. More and more forests are being cleared every year, removing valuable trees that sequester carbon dioxide and help quell global warming. By 2050, the population is expected to jump to 9 billion--how will the land be divided up?
If it were up to Despommier, a microbiologist at Columbia University, the answer lies in urban farming. Despommier envisions 30-story skyscrapers where crops are grown on every floor, each providing enough food and water for 50,000 people.
More than 100 crops can be grown indoors by taking advantage of a technique called "hydroponics," where plants grow using mineral nutrient solutions instead of soil. The plants would travel down conveyer belts past stationary grow lights and automated nutrient-delivery systems. Genetic engineering, where researchers can control the characteristics of an organism, could play an important role in the vertical farm concept by modifying the growth requirements of different crops.
In terms of water production, the skyscraper farm could use a process called "evapotranspiration," which is basically the condensation that comes from plants' leaves. Despommier plans to irrigate the plants with sewage that has been filtered through barrier plants and zebra mussels, which are the best-known filtering organism.
Despommier is also part of New York Sun Works, an eco-friendly engineering firm in Manhattan concerned with global warming and agriculture--the top cause of pollution. By using compact vertical farms instead of clearing more land, forests could be saved and trees grown to help combat global warming.
Although Despommier predicts that the first vertical farm will likely cost billions of dollars, with funding, he thinks a prototype could be constructed in five to 10 years. One day, he envisions an entire skyline dotted with skyscraper farms