Lighting is only the most, um, glaring problem with vertical farming. Growing crops in buildings (even abandoned ones) would require far more construction materials, water, artificial nutrients, energy for heating, cooling, pumping, and lifting, and other resources per acre than are consumed even by today’s conventional farms—exceeding the waste of those profligate operations not by just a few percentage points but by several multiples. Vertical enthusiasts also claim that crops grown in buildings chemical-free will somehow be protected from diseases and pests, but as anyone who has worked in a greenhouse can tell you, epidemics and infestations can explode into total losses overnight on plant grown in confinement.
And raising crops in such restricted spaces would, necessarily, mean substituting a lot of human labor for much of the mechanical power now used in farming. That’s fine environmentally, but who will own these enormous high-tech facilities, how much of the hard work—hauling, transplanting, tending, harvesting, more hauling—will be done by idealistic entrepreneurs, and how much will end up being carried out by the same underpaid, overexploited people who do all that grueling stoop work that currently provides us with most of our vegetables and fruits today?
The goals of the vertical-farming concept are generally laudable (Despommier’s Wikipedia-page photo features a slide showing the word “hunger” canceled with a red circle-and-slash) but it has virtually no potential for saving soil or strengthening food security. It’s just another proposal (if probably the most high-input one) for urban agriculture, a practice intended to reduce the distances that food is transported while supporting local economies. There’s no doubt that local fruit and vegetable production is good for consumers. But even if we planted every urban flat roof while deforesting and farming all of America’s front and back yards and open urban spaces, we could supply only a tiny portion of the nation’s food supply. Add in those 105,000 Empire State Buildings full of vegetables, and we’d still have well over 95 percent of food being produced outside of cities.
And ecological impact cannot be estimated simply by counting food miles; food’s ecological footprint lies mostly in production, not transportation. Were vertical-farm planners to add up the enormous quantities of energy and materials required for construction, maintenance, operation, and eventual dismantling, they would be forced to conclude that the structures they’ve envisioned can succeed only in supplying the more affluent city-dwellers with leafy salads.
If we want to protect North America’s soils, the most effective immediate action would be to stop degrading scores of millions of acres every year to raise corn and soybeans for making biofuels and feeding cattle. Those landscapes should be restored as grasslands (and, eventually, mixed stands of perennial grain crops.)
The current corn-and-soybean system serves only to keep animals alive and unwell in confinement, with an extraordinary waste of resources. But if we want to resolve the myriad problems currently created by factory-farming animals in sheds and feedlots, we’ll never do it by factory-farming plants in skyscrapers.
