The days of acre after acre of crops stretching as far as the eye can see may be numbered. Confronted by the colliding realities of a growing population and a finite amount of land worldwide available for food production, Columbia University environmental health science professor Dickson Despommier developed a new solution: Farm "vertically" -- in tall buildings.

According to Despommier, the need to pursue vertical farming is urgent. "We need to devote the level of attention to vertical farming that we did to going to the moon," he says. "It will free the world from having to worry about where our next meal will come from."

The numbers help make his case: Students in the professor's medical ecology class determined that a vertical farm of about 18 stories, set within a city block could feed 50,000 people. Add more height, feed more people.

Where to build the world's first vertical farm? Why, Las Vegas, of course! With a projected price tag of $200 million the farm will double as tourist attraction, and feature approximately 100 crops spread throughout the building's 30 stories.

Read more at Cleantech.com

Photo by Joelle Maslaton