Don’t miss this piece  (HT: Tamara Kupfer) in the NYT by Stephen Budiansky. An excerpt:
But the local food movement now threatens to devolve into another one of those self-indulgent — and self-defeating — do-gooder dogmas. Arbitrary rules, without any real scientific basis, are repeated as gospel by “locavores,” celebrity chefs and mainstream environmental organizations. Words like “sustainability” and “food-miles” are thrown around without any clear understanding of the larger picture of energy and land use.The result has been all kinds of absurdities. For instance, it is sinful in New York City to buy a tomato grown in a California field because of the energy spent to truck it across the country; it is virtuous to buy one grown in a lavishly heated greenhouse in, say, the Hudson Valley.
His blog post  on the same topic is also excellent. An excerpt:
The larger point is that not only is it not really bad to eat non-local food: eating food from a long way off is often the single best thing you can do for the environment, as counterintuitive as that sounds. The relative pittance of energy we expend on “industrial” agriculture (agricultural production consumes just 2% of total U.S. energy use) pays huge environmental dividends which the organic and local gurus always ignore: intensive farming via chemical fertilizer and machinery have spared literally hundreds of millions of acres for nature that would otherwise have come under the plow. (For a brilliant analysis of this, see the study  by Paul Waggoner of the Connecticut Agricultural Experiment Station, a member of the National Academy of Sciences and one of the clearest thinkers on the subject of agriculture and land use.) So two cheers for that California lettuce.