I'm more concerned about the potential problems related to food, water and air than I am about those related to petroleum, metals and minerals. I agree that it

I'm more concerned about the potential problems related to food, water and air than I am about those related to petroleum, metals and minerals. I agree that it's important to know "the true cost of things." It's the main point of the article and advice well taken. Much of the sand our present economy seems built upon is directly related to "not knowing the true cost of things" or at least "not being willing to accept the true cost of things."