in order to bring in a permaculture regime, we'd have to kill 99% of the population, which is what we're trying to avoid. estimates of what permaculture can support are about 200 million people, total. globally.
there's roughly 7.8 billion people right now.
100*7798/7800 = 99.974358974.
that's the percentage of the current world population that would need to die to bring in "sustainable permaculture".
we need a system that is both sustainable and scalable, and the way to do that is to get rid of the soil altogether, using hydroponics: