your other questions have been answered well by others here, but i'll just throw in my own prediction: i think the future will be mostly vegetarian, with rural or suburban chickens producing eggs as a primary meat based protein source, very rarely eaten and well taken care of (basically domestic yard chickens, which tend to be really sweet for birds). you may have a few community dairy cows that graze freely that everyone gets some milk from and cheese may be made for local consumption. and in some parts of the world, local hunting may provide occassional meat (deer, etc). but industrial meat industry is dead whether the climate, the market, or a glorious socialist revolution strikes the killing blow.