In a photo provided by Goldberg McDuffie Communication, Dickson Despommier, a professor of public health in environmental health sciences at Columbia University is seen in an undated photo. Despommier's book titled "The Vertical Farm" was published in Oct. 2010, and explores the possibility of farming in skyscrapers as a way to solve food and fresh water shortages. (AP Photo/Goldberg McDuffie Communication, Marlene Bloom, HO)

Photo by: Marlene Bloom

In a photo provided by Goldberg McDuffie Communication, Dickson Despommier, a professor of public health in environmental health sciences at Columbia University is seen in an undated photo. Despommier's book titled "The Vertical Farm" was published in Oct. 2010, and explores the possibility of farming in skyscrapers as a way to solve food and fresh water shortages. (AP Photo/Goldberg McDuffie Communication, Marlene Bloom, HO)