Part of the thought was to also reduce transport cost. So if you have effectively the harvest and distribution localized one would reduce footprint in other wa

Part of the thought was to also reduce transport cost. So if you have effectively the harvest and distribution localized one would reduce footprint in other ways. That being said I'm not saying "expensive urban rooftops" are where we should be doing this. I was simply suggesting there are other changes afoot that are, for example, increasing yield. Any location will have pros on cons such as locality, cost, infrastructure, space reuse, etc.