I started watching this talk because it is about vertical farms, but the speaker, Dickson Despommier, spends a lot of time explaining what the problems we face as a planet are, leaving less for detail on vertical farms, which for him are part of the solution.
This doesn't detract from the talk overall, though if you're more interested in vertical farms in a technical way, you may need to look elsewhere, or follow up the sources used in the talk.
The main thing I took away from the talk is Despommier's bottom line, or sine qua non, or key aim that there should be adequate water and nutrition for every human being as a birthright (ie not something that you have to work for, nor something which is granted to you by a government or other person or institution). Also, he actually quantifies 'adequate' as being 2.3 litres of fresh water and 1500 calories in food per person per day. I have no means to challenge these quantities, nor reason to doubt them, but having even a working estimate enables calculations to be done and gives clarity for planning purposes over and above the more nebulous/subjective "adequate".