Serious Eats - seriouseats.com

I don't even want to know what mine is. Probably enough to...power...a small country.

I buy local because I like feeling in touch with the seasonal changes around me and in touch with the people who grow my food. The environmental benefits are secondary, and from the Observer article, it sounds like much of the negative environmental impact comes from buying local out-of-season items. Eat seasonally.

Environmental impacts will vary from food item to food item; for people looking for a rubric by which they might shop to minimize impact without researching every ingredient, local's pretty good. (Though I do appreciate that giving up meat & dairy would be better!)

My support of local foods is based on the cost of transport increasing the price we pay, and the loss of family farms keeping the earnings of farmers down with the money paid for food going mostly to multinational corporations rather than those who grow and pick our food.

One of the nice things about the local food movement is that different people can interpret it in different ways--some people can plant their own gardens; others might just favor American apples over New Zealand apples. This makes the term local more powerful because more people can get behind it. And in some ways, it makes the word less susceptible to coopting in the way that organic has been.

The Observer story (and the February 25, 2008, New Yorker story on carbon footprints, "Big Foot," by Michael Specter) make clear that what we eat, like other daily decisions, "is almost never easy." But that doesn't have to send us into a state of gastro-paralysis. And while the variety of international shipping technologies, agroecological conditions, and farming practices around the globe conspire against simple answers, there are some rules of thumb that the carbon-conscious eater can live by.

A meat-rich diet generates more carbon than a diet with moderate amounts of meat. Highly-processed foods--whether canned, frozen, or fried--use more energy than raw items. Organic production of everything from apples to milk to wheat generates less carbon than chemical-based production, largely because the organic farmer's fertilization strategy doesn't depend on petroleum based agrochemicals and can actually add to the soil's store of carbon. And, in general, buying food grown closer to where you live will save fuel used in shipping.

Yes, a diligent research can find exceptions, like the New Zealand lamb raised on year-round pasture that is less fuel intensive than local lamb that might have to be given feed in the winter. But even if an 18-wheeler shuttling California asparagus to New York City is more energy efficient than a battery of beat up farmers market trucks bringing green spears to Union Square, New Yorkers who forsake out-of-season produce entirely render the long-distance advantage moot.