Evidence of the really top-notch analysis my readers get for free, day in and day out . . .
I've argued before that those who worry about how far their food travels are focusing on the wrong thing. Here's some of what I wrote back in April:
The food-milers make another mistake, perhaps one worse than fixating on the wrong metric. They ignore the fact that lots of energy is used at every step of the soil-to-plate cycle. Fertilizer. Irrigation. Tilling. Harvesting. Storage. Processing. Transportation. Everyone knows that the recent surge in food prices was caused by the sustained surge in fuel prices (aggravated by the government's edict that we fuel our cars with food).
This is an important reason not to worry about fuel miles. It's actually very, very tricky to calculate the amount of energy used to get food from the ground to the market. Growing conditions matter a lot. Florida growers can grow 2 or 3 times or more tomatoes per acre than Texas growers. Local growers thus start at a huge energy disadvantage unless they are using radical farming methods that use no energy (also known as "subsistence farming"). It's quite possible that they cannot close the energy gap despite their advantage in transportation costs.
Here, via Ezra Klein, is confirmation (OK, it's merely evidence) that I am right:
[T]wo Carnegie Mellon researchers recently broke down the carbon footprint of foods, and their findings were a bit surprising. 83 percent of emissions came from the growth and production of the food itself. Only 11 percent came from transportation, and even then, only 4 percent came from the transportation between grower and seller (which is the part that eating local helps cut). Additionally, food shipped from far off may be better for the environment than food shipped within the country -- ocean travel is much more efficient than trucking.
In other words, if you're worried about minimizing the energy used to get food to your table, you're better off asking whether it was grown in the most energy-efficient environment (i.e., the soil quality and growing conditions) rather than how far it traveled.