Study finds that it’s what you eat, not how far it traveled

I attended a couple sessions at the Brooklyn Food Conference on Saturday; there was, of course, a lot of talk of one’s “foodprint” (GHG emissions generated by diet). I learned that one person eating local for one year saves the equivalent GHG emissions as a 1,000-mile car drive — honestly, that isn’t much. It’s the same as taking a few dozen less trips to the store, or skipping a road trip. And given that local doesn’t always mean sustainable and efficient (for example, apples produced in New Zealand may have a lower footprint than those produced in New York, even for New Yorkers), it may be more critical to reduce emission-heavy foods, wherever they’re from.

Researchers at Carnegie Mellon have found that producing food in the average American diet generates more GHG emissions than transporting it to the supermarket. Their conclusion is that eating less meat, particularly red meat, and dairy products is the most effective way to reduce your “foodprint.” They write:

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 8.1 t CO₂e/yr 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.