Can we pull of Urban Farming

Fast Company recently featured this write up and video. The more I study food and where it comes from I'd love to be able to know exactly where My food comes from and if possible supply inner city kids with some new food options.  The post and video ( no audio) break down the requisite land needed to sustain an individual. whileThis may not present an easy option but what things that are really value are?

As city-dwellers around the world discover the importance of locally-grown food, visions of self-sustaining cities continue to grow. But how feasible is urban farming on a large scale? According to this video based on research from MVRDV, The Why Factory, and Stroom Den Haag, not very. In the end, the video concludes that "To strive for complete self-reliance with food in cities is currently not sensible", but still worth pursuing. Decide for yourself after watching the clip below.