Vertical Farming Concept

"By the year 2050, nearly 80% of the earth's population will reside in urban center's. Applying the most conservative estimates to current demographic trends, the human population will increase by about 3 billion people during the interim. An estimated 109 hectares of new land (about 20% more land than is represented by the country of Brazil) will be needed to grow enough food to feed them, if traditional farming practices continue as they are practiced today. At present, throughout the world, over 80% of the land that is suitable for raising crops is in use (sources: FAO and NASA). Historically, some 15% of that has been laid waste by poor management practices. What can be done to avoid this impending disaster ?" (read on)

Dr Dickson Despommier in this video proposes city based fruit and vegetable farms that are housed in office towers. We have to keep in mind here that the good Doctor, at most is sketching a concept and ought not be held for lacking details and or a hard edge plan !

I'm guessing that city planners in arid countries like Dubai may already be considering vertical farms !