As a confirmed foody, I am certainly aware of the "Eat Local" movement, and even know a couple of "locavores". The first time I was made aware of this was an article I read in a magazine somewhere about the chefs at Google's campus in California seeking locally-grown food. My inner Texas oilman said "I wonder when the hunting season is on cartoon songbirds that flit around the heads of Google Chefs". My inner hippy cosmonaut said "that's kinda cool". Then the inner oilman tried to stomp the inner hippy in a kind of "Easy Rider" ending. It was ugly.
In reality, although, as a Texan, I am often guilty of applying the "Everything Californian Is Complete BS" filter, the local food movement was something I couldn't throw out whole cloth. The major premise is that the closer the food is to market, the more resource you can save. There is a whole Local Economy thing also tied up with the movement that I don't get, since they don't build cars and TVs anywhere around where I live, and I doubt if I would buy a locally produced TV from the local commune even if I could. In any case, "Local Food" has stuck in the back of my head until I decided to do some "ciphering", as Jethro Bodine, my own personal icon, might put it.
The whole "Local Food" resource saving argument falls apart if you are dealing with a local hippy farmer who drives his pickup to the farmers market, loaded with 500 lbs of produce, for Saturday sales. 18 Wheelers are just much more efficient. The fuel burned per pound of food is the same moving 500 lbs of 50 miles as it is moving a tractor trailer containing 60,000 lbs of food 2000 miles. Of course, this efficiency shows up in cost. In this case, the environmental impact is proportional to the economic impact, since transportation is the only metric being measured. The answer in both cases is around 0.005 gallons per pound of food delivered. In reality, the local comparison looks twice as bad if the pick up truck is driven back to the farm empty, since the big rig will likely pick up a load of something at destination for delivery elsewhere.
The only way to make the Locally Grown case work, at least from a "resource consuption" point of view, is to move it via big rigs the 50 miles to market, which implies a lot more than a local farmers market and a few restaurants. It demands scale, on both the farm and market side. A lot of storage logistics then need to be implemented that require "hidden" resource consumption.
In reality, a lot of our hyper-efficient, just in time delivery world is nearly, by definition, the best steward of environmental resource. Maybe not all, but the majority for sure.