Cities may sprout vertical farms
Proposed high-rise greenhouses could help solve a looming food crisis, professor says.
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That’s why the idea of “vertical farms” seems ripe for humor. When its biggest advocate appeared on the faux news show “The Colbert Report” earlier this year, comedian Stephen Colbert prefaced the interview by guessing it would have something to do with corn that grows sideways or perhaps “Chia blimps” that float overhead.
Such teasing hasn’t deterred Dickson Despommier, the Columbia University professor of public health. He sees putting crops into skyscrapers as a better way to feed a hungry world. Professor Despommier’s website, verticalfarm.com, features architectural concepts of high-rise buildings that could grow fresh produce in urban areas while at the same time being much more environmentally sustainable than conventional agriculture. [Editor's note: The original story misspelled Dr. Despommier's first name.]
The trouble is, he concedes, none of the beautiful drawings would work exactly as shown. “They all look pretty,” he says. “[A]t least it means they’re thinking in the right direction.”
What’s needed before millions of dollars are spent to construct or renovate an existing 30-story building into a vertical farm, Despommier says, are prototypes just a few stories high. They should be built at leading agricultural universities and tinkered with until the concept is proved. “Once it does, drive it out of the showroom and take it home,” he says.
While Despommier has won admirers around the world for his innovative thinking, skeptics still wonder how he’s going to handle the problem of solar energy – bringing necessary light to the interior and lower floors of his agri-towers. “As soon as you go vertical, you compound that problem of getting that [solar] energy to the plant,” says Gene Giacomelli, director of the Controlled Environment Agriculture Center at the University of Arizona in Tucson.
Dr. Giacomelli likes the audacity of vertical farms, but says a lot of problems must be solved first. Despommier, he says, “is a forward thinker. He’s challenging all of us to try to make it happen.”
The challenges also include finding and training indoor “farmers” who can operate what is likely to be a complex system. “There’s nobody at the moment,” Giacomelli says. The technical problems aren’t insurmountable – crops are being grown indoors at the South Pole, albeit at great expense, he says. But, he adds, “There are many more ways to fail [at indoor agriculture] than to grow a crop correctly and succeed.”
The world is going to need vertical farms because conventional agriculture can’t handle what’s to come, Despommier says. By midcentury, the world is expected to add another 3 billion people, pushing its population close to 10 billion. Feeding all those extra mouths will require finding an area of agricultural land larger than Brazil – without cutting rain forests needed to stabilize the world’s climate.
Heading skyward, under the controlled conditions of an indoor greenhouse, has many advantages, Despommier says. “You can control nothing outdoors, and you can control everything indoors,” he says. That means no floods, wildfires, hailstorms, tornadoes, or droughts. Plant diseases and pests are more easily controlled, too, meaning less need for herbicides and pesticides.
And indoor agriculture is more efficient. One indoor acre of strawberries can produce as much as 30 outdoor acres can. In general, indoor acreage is four to six times more productive, in part because of the year-round growing season. “Outdoors, you might get one crop [per year]; indoors, you might get four or five crops per year,” Despommier says.