"To use vertical or rooftop gardens to take more land out of agriculture is dead wrong,"
It would seem to me that vertical farming has the advantage of longer growing seasons and locally grown food (less fuel), but:
1. Growing dirt has to come from somewhere (farmland?) unless it is a aquatic farm (makes nice looking tomatoes, but less nutrition).
2. In a constrained space, it would need considerable fertilizer - unless they shipped manure+ in, which lowers the supply elsewhere, therefore requiring more fertilizer elsewhere.
3. It might economically viable if they used cheap (condemned for living) existing buildings. However, it would probably have to be organic to bring higher, speciality prices for profit reasons. This would make it a nitche market. Interesting but small (prices).
Market Data 
Markets 
AI
