Your problem is going to be that you not only need butter but also need a myriad other things and only a few of those can be self sufficient in a small local co

Your problem is going to be that you not only need butter but also need a myriad other things and only a few of those can be self sufficient in a small local community. Yes, we shouldn't truck things from half a country away but that doesn't mean the energy consumption / CO2 footprint at the end of the day will be lower for a sprawl than a dense city. Yes, cutting back to medieval times, wearing homespun, most amenties supplied by the local blacksmith and cobbler and some things supplied by traveling merchants , that'd obviously be more environmentally friendly. I doubt most people are ready to do that. And also -- Malthus would like to have a word with you. No way you can supply this many people with such technology. Yes, the ultimate green solution is to decrease the amount of people living on Earth but check how China did with the one child policy.