How many food shortages have occurred in industrialized nations in the past 50 years that were a result of natural conditions? Compare that to the uncertainty that comes with depending on local phenomenon and get back to me.
As with the universe and planet we live on, 50 years is not enough time to judge anything by. Conditions change and the earth changes, so while we may have dodged the bullet to date, that doesn't mean we won't catch it later, and dependency on companies like Monsanto who we all know could care less about the integrity as they do the bottom line, as that's the purely business end that drives it, is not where I would like to see our food industry. It's not where I would like to see my own state and local addicted to. None of that helps Louisiana farms, agriculture, or economics, in as much as shopping at Walmart helps stymie local entrepreneurship and a healthy local market. It drives locals out of business.
This may be true - to an extent. However, the fuel expended by a multitude of small farmers, delivering either to a market or directly to their customers under the CSA model (or customers coming to them) is greater than the fuel expended by an industrial distribution system, in many cases.
If so, then that may very well be attributed to the lengths they have to go to in order to bring their products to market, or those who even have room for their products on their shelves anymore. Truth be known, the real reason for all of this is that the people themselves don't see the value in it, for. If they did, there would be farmers markets all over town, open 7 days a week, and pumping out business right and left, but that's not the case here at least. Elsewhere, much more so, but it's still a foreign concept to most here, which is pretty strange that it is considering we are only a few generations removed from that being the norm rather than a foreign concept.