Altering our diets or dietary production habits to save civilization.

 Humans have altered their diets and resource consumption habits or water usage throughout history based on what was available and sustainably usable. Where we have gotten into trouble is when we disregard these factors and that is how civilizations have often collapsed throughout time. The difference right now is that we know of sustainable practices but don't have the wherewithal to implement it because of the market economy and it doesn't make a buck or a few rich people control the economy instead of us all through a people controlled system.