Fritz Haeg has been deemed a horticultural revolutionary of late for daring to propose scrapping front lawns for “edible estates.” But his proposal pales compared to Columbia professor Dickson Despommier’s vision of entire skyscrapers devoted to growing crops. Such “vertical farms” could reduce the carbon footprint of city dwellers by conserving energy used for long-distance transport of food to urban markets. Even better, they could free up expanses of farmland to return to forest, radically reducing the amount of carbon dioxide in the atmosphere.

Among the other benefits of skycropping: a year-round supply of organically grown fruits, vegetables, grains, and fish; no weather-related crop failures; no polluting agricultural runoff; lots of green collar jobs in inner cities; and an intensive form of food production capable of feeding the 3 billion additional people predicted by the year 2050, most of whom will live in urban areas.

Several sky farm designs are featured on Despommier’s website. He says roughly 150 30-story towers could feed the entire population of New York City for a year. This article, published in New York magazine last year, explains in detail how they would work.

A reader asks:

“How does the carbon footprint of homegrown fruits and vegetables compare with that of imported produce?”

In the past few years the carbon footprint of food has become one of the hottest issues in the western world. A number of luminaries have weighed in on the subject in the U.S. alone, from best-selling novelist Barbara Kingsolver (in Animal, Vegetable, Miracle) to ethnobotanist Gary Nabhan (in Coming Home to Eat). All this discussion has generated its own jargon, including such terms as “food miles” (the distance any item of produce travels from farm to table) and “locavore” (a person who makes a point of eating food grown within 100 miles, give or take).

At first glance comparing, say, a tomato grown 30 feet from your back door with one cultivated half a continent away would seem to be a no-brainer. (more…)