"By the year 2050, nearly 80% of the earth's population will reside in urban centers. An estimated 109 hectares of new and (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. (and thats not even talking about global warming...) What to do about this impending food crisis? Many think the solution might lie in urban 'skyscraper farms'."
