No
Or, perhaps Yes.
Youtube doesn’t like my adblocker, but whatever that video says, you aren’t feeding 9B people by growing lettuce on apartment roofs. I love Joe Salatin, but he’d be the first to tell you that’s bullshit.
Have you ever grown a fruit or vegetable? It sounds like no.
The video goes over the potential yields if cars were mostly replaced with public transport, and most of the now unused roads and parking lots in cities were converted to growing space (with some rooftop gardens as well).
Edit: I forgot to mention, the video mainly suggests that cities can be self sufficient in their food supply, not that they would have an excess to export out of cities. But it suggests that the same techniques could be used for less urban areas as well so that they too could become self sufficient.
So it assumes the entire world is built like American suburbia, which isn’t even financially viable right now when it can just dump its pollution and waste at little to no cost, and which is causing immense mental health crises due to the huge distances between friends and even neighbors?
Good luck getting self-sufficiency in Tokyo or London without vertical farms powered by giant fields of solar panels outside the city that could more easily have been used to grow the same stuff directly.
Hm, from what I recall, it mentions the differences in density between various cities and how that effects the techniques used. Could you link a timestamp of where he says it’s only for US suburbia?
It pisses me off that because cities grew up where agriculture worked best that cities are on the best farmland in their areas. But the amount of land it takes to efficiently grow crops is many, many times what the cities have available even being ridiculously utopian about what can become available with schemes like “get rid of vehicles”.
On top of all that, the energy it takes to use grow lights for millions of acres of hydroponics would make AI datacenters look like power misers, and then you have to find people that would actually want to work in them. Farmers today can’t even charge enough to give people a living wage picking strawberries when there’s no added costs like that, and cry when their undocumented quasi-slave labor gets shipped back to Mexico. How’s all that going to work?
The key is to genetically modify people to have chlorophyll skin; it would be more likely to come true.
The video creator does not assume hydroponics with grow lights, but open-air traditional growing techniques. Only in the case of extremely dense cities with little room, is aquaponics or chinampas considered.
But the amount of land it takes to efficiently grow crops is many, many times what the cities have available
David R. Montegomery’s book, Dirt referenced some interesting studies which seemed to indicate that urban farming can potentially out-produce industrial agriculture by 10 to 100 times, depending on the size (the smaller the farm, the more potential productive capacity).
Screenshot of the book referenced in another video (unfortunately also youtube):
That second video also referenced this interesting experiment by someone trying to sustain themselves off a small garden with limited time and effort put into it:
https://www.unsustainablemagazine.com/home-gardens-vs-farms-efficiency/
