Atypical farm burns vast quantities of fossil fuels to plow fields, sow seeds, reap harvests and truck products many miles to population centers. It spreads heaps of petroleum-based fertilizers, which then run off into streams and watersheds. It also consumes rivers of freshwater and casts pesticides across the countryside. Raising chickens and pigs further insults the earth with unhygienic filth.

Why not grow grains, vegetables and fruits right where the expanding crowds of consumers are: in the middle of a city, inside a tall glass building? Poultry and pork could be reared there, too. A vertical farm would drastically reduce the fossil-fuel use and emissions associated with farm machinery and trucking, as well as the spread of fertilizer and its runoff. Crops could grow and be harvested year-round instead of at the end of one season, multiplying annual yield by at least four times. Urban agriculture could also convert municipal wastewater into irrigation water, reducing a city’s refuse problem. And consumers would get the freshest food possible, without pesticides.