Don't know much about it, but I'm just going to assume this is a bad idea. I mean, a bad idea: the kind that our kids will laugh at, the way we look back at the early, schematic drawings of whimsical flying contraptions.
It seems like a decent idea - after all, it's someone talking about investing heavily in a form of local agriculture, and that is good news. But if we're talking about "hundreds of millions of dollars" to build even one of this guy's dream agri-skyscrapers, I have to think: why can't we generate half that capital to support traditional small farms that have proximity to cities? Let's give it to Liz's farm!
Tangentially, this is remarkable:
"Stephen Colbert jokingly asserted that vertical farming was elitist when Dr. Despommier appeared in June on 'The Colbert Report,' a visit that led to a jump in hits to the project’s Web site from an average of 400 daily to 400,000 the day after the show."