The Locavore's Dilemma

ExoticsThat's how Andrew Sullivan describes the results of a recent study from Carnegie Mellon on greenhouse gases and food production.

Michael Pollan's book the Omnivore's Dilemma can be credited with fueling much of the interest in local food. In his book he explains that the average item of food on our American dinner tables travels an average of 1500 miles. He concludes, as have many in the local food movement, that the responsible thing to do is eat locally, therefore reducing one's contribution to greenhouse gases.

Foodmiles_3The dilemma is that this intuitive logic may not be as sound as originally thought. This is how Carnegie Melon sums up the results of their study.

Despite significant recent public concern and media attention to the environmental impacts of food, few studies in the United States have systematically compared the life-cycle greenhouse gas (GHG) emissions associated with food production against long-distance distribution, aka “food-miles.” We find that although food is transported long distances in general (1640 km delivery and 6760 km life-cycle supply chain on average) the GHG emissions associated with food are dominated by the production phase, contributing 83% of the average U.S. household’s footprint for food consumption. Transportation as a whole represents only 11% of life-cycle GHG emissions, and final delivery from producer to retail contributes only 4%. Different food groups exhibit a large range in GHG-intensity; on average, red meat is around 150% more GHG-intensive than chicken or fish. Thus, we suggest that dietary shift can be a more effective means of lowering an average household’s food-related climate footprint than “buying local.” Shifting less than one day per week’s worth of calories from red meat and dairy products to chicken, fish, eggs, or a vegetable-based diet achieves more GHG reduction than buying all locally sourced food.

Go here and here for some bloggy reactions. You might think this would take the air out of our year of plenty party balloon, but greenhouse gases have never been the metric that drives our experiment. Here's how I responded to this kind of question in the comments of a previous post.

On the gas mileage issue I think there are legitimate questions around what is best regarding fuel consumption. Some have speculated that it could be more efficient to have one truck traveling a thousand miles to one location than to have dozens of small farmers trecking in for the Farmers' Markets. We certainly have found ourselves making trips to out of the way places. I can only speak for myself on this, but the way I sort through that is to look not just at my consumption of fuel but the total picture of consumption in my life. The key point for me is not carbon footprints, or greenhouse gases, rather it is relationships, and caring for people. I trust, maybe naively, that if I shape my life around that "ethic" that things like carbon footprints and issues of justice, will follow as I am faithful to that bigger picture.