We have put a lot of stuff into the water that does not treat out. There is a ton of chemicals, and a lot of those we consume as pharmaceuticals, that are pretty much there to stay. Over time those will only get worse. Our food resources are another example of us meddling. We farm livestock that is quite poorly suited to the terrain and have all but eliminated the animals that once roamed in abundance. Our crops are currently more chemistry experiments than anything else. Those keep getting to be more and more modified and more and more people are having difficulty consuming them. Perhaps that is how we will adapt, only those that are able to live on our chemistry experiments will survive. You are correct in that food is not the problem, distribution is the issue. I think that is true with some of the population as well.