Dickson Despommier, who has made appearances on GOOD here and here, is one of the world's leading advocates of "vertical farming." The idea is we should grow our food in multi-story, closed-loop urban agriculture facilities as a way of reducing the resources used to produce and transport it.
Despommier has a new book out called, appropriately, The Vertical Farm. Here he is introducing the idea.
Vertical farming has its critics. George Monbiot, for example, is harsh in his assessment of the idea. Monbiot argues that vertical farms could not, as Despommier claims, function without pesticides, and moreover, that the costs to build and operate a vertical farm make it impossible as a business.
And the biggest problem, according to Monbiot, is light:
The light required to grow the 500 grammes of wheat that a loaf of bread contains would cost, at current prices, £9.82. (The current farm-gate price for half a kilo of wheat is 6p). That's just lighting: no inputs, interest, rates, rents or labour. Somehow this minor consideration – that plants need light to grow and that they aren't going to get it except on the top storey – has been overlooked by the scheme's supporters.
If—knock on wood—we do invent some new super-efficient solar power technology, that might lower the costs of the lighting significantly. But then again, it would also lower the energy costs of traditional farming as well.
I haven't read Despommier's book. Perhaps he addresses some of these concerns. But for now count me as a reluctant skeptic.