In 2007, Wired magazine ran an article about how vertical farms could help feed an exploding world population. The article argues:

“[B]y 2050, Earth’s population will swell to 9 billion people. Feeding them — especially if they demand protein-rich Western diets — will require a doubling, even a tripling of global food supplies. But more than a third of our planet’s surface is already devoted to agriculture; there’s not much arable land left. Droughts, floods and soil depletion will only grow more destructive as climate change intensifies.”

The recent op/ed in the New York Times by vertical farm entrepreneur Dickson D. Despommier echoes and amplifies those concerns:

“Three recent floods (in 1993, 2007 and 2008) cost the United States billions of dollars in lost crops, with even more devastating losses in topsoil. Changes in rain patterns and temperature could diminish India’s agricultural output by 30 percent by the end of the century. What’s more, population increases will soon cause our farmers to run out of land. The amount of arable land per person decreased from about an acre in 1970 to roughly half an acre in 2000 and is projected to decline to about a third of an acre by 2050, according to the United Nations. With billions more people on the way, before we know it the traditional soil-based farming model developed over the last 12,000 years will no longer be a sustainable option.”

Dire warnings indeed. And the solution that Despommier proposes holds out the hope that we can build vertical farms in urban areas using hydroponic and aeroponic soil-free technologies. Despommier paints a pollution-free vision of these future farms where the water is recycled and the carbon footprint is reduced because tractors no longer go over the fields, while compacting the soil.

Despommier makes vertical farms sound appealing, and adding a roof garden wherever possible certainly makes good sense. But unanswered in this vision is how much of a burden the power requirements will put onto our planet, since we can only assume that the plants grown on interior floors will require some kind of grow-lights.

Unaddressed as well is that the bulk of our farmland in the United States is not used to grow fruits and veggies, but commodity crops such as corn and soybeans. How much longer can we justify raising corn for ethanol and high-fructose corn syrup that contributes to obesity when that land might better be put to use raising real food (fruits and veggies) for real people? And what makes us think that a population of 9 billion is sustainable? And what can we do, humanely and effectively, to reduce family size around the world?

Viewed through that prism, perhaps we do not have as much as a land shortage as a shortage of vision.