Vertical farming

A vertical farm is a greenhouse for growing foodstuff in a skyscraper. The idea is intriguing, but according to [this article from The Economist](http://www.economist.com/node/17647627) it's not likely to succed without very cheap, clean energy.

See also [Wikipedia's article](http://en.wikipedia.org/wiki/Vertical_farming).

A leading advocate for the technology is Dickson Despommier. [Here](http://www.verticalfarm.com/) is his site.