Lets remember that sustainable and self sufficient are two different terms.
A practice is sustainable if it can be continued indefinitely without detriment to the environment or whatever system it is part of.
Original link is dead. You can download it here, but need a scribd membership: https://www.scribd.com/doc/2100251/Jared-Diamond-The-Worst-Mistake-in-the-History-of-the-Human-Race
|And now I present magical permaculture hypno cards. The idea is to give them to people that think all your permaculture babble is crazy talk. And be amazed as they apologize for the past derision, and beg you for your permaculture wisdom. If only there were some sort of consumer based event coming where you could have an excuse to slip them a deck ... richsoil.com/cards|