From a farmer's standpoint, I think the best way to start to understand the true meaning of sustainable is to make sure you are educating yourself about the seasons.  I often find it difficult to understand how people do not innately know what grows when and where, but then I pause to realize that I have been growing in the desert for almost 12 years now, and things that I know are just part of being a farmer.  I look back to  the days when I would go to Baker's Nursery and lock onto every word the patient Bakers daughters would impart to me!  It's a learning experience for everyone else too, as I am reminded every year when we have tomato transplants out in the spring.  The types of questions I hear  find me repeating the same concepts over and over, but I always end by saying, "Go ahead and try it!"  The worst that can happen is that your plant won't grow or die, but the best is that you will gain some insight into the nature of the world and the delicate balance that it requires.  

So as current politics have all eyes turned to high education fees and our right to have an education, I think that much of the education in daily life skills that we can gain in food safety and sustainability is not primarily from a class or an expensive university, but is free in hands on experience, and this is how we remember best what we have learned.  I still remember my many past failures and especially the successes, and always try to apply that to the next year, gettting better at what I do, simply by the try and try again theory.  So go ahead and plant something!  It really doesn't matter what or how well it performs, as you can weigh your success or failure at the end of the season, but once you know how and what grows here in the Valley of the Sun,  you will have an enormous advantage over the person who knows only what is published on the "Eat Seasonally" lists that come out in every Edible Phoenix Mag.  And since knowledge is something that you can build on, you will soon find you too have an innate understanding of what eating seasonally and especially what sustainable can really be in all of its many forms.  You will find that by starting small, and building on it, you can truly make a difference, and maybe someday, you might become part of my perfect version of the future of farming!