Vertical Farming

Supposedly, 80% of the land that can be used to grow crops is already in use, and
15% of that land has been damaged by poor agricultural practices. A new concept in farming is supposed to help feed a bumper harvest of 3 billion
new people over the next 50 years. 

Vertical farms, many stories high, will be situated in the heart of the world’s urban centers. If successfully implemented, they offer the promise of urban renewal, sustainable production of a safe and varied food supply (year-round crop production). Treehugger comments:

"Personally, I’m more excited about this concept as a way to help us
stop the use of pesticides, herbicides, oil-based fertilizers, and to
give a break to a lot of land that we have been stressing for decades
than as an extra food source. Another advantage: the food would grow
quite a bit closer to the consumers, something that will become more
important as oil prices keep rising and transportation on long
distances becomes a luxury (no more kiwis from New-Zealand in Canada
during the winter)."

TreeHugger