Food choice more important than food miles

Get used to hearing more and more about the "carbon footprint" of consumer products in coming years. Much of the focus will be toward elevating locally grown food as a way to reduce environmental impacts, but a recent study indicates that consumer choice of food types- whether plant-based, dairy or meat - has a much greater impact on greenhouse gas emissions than factors such as "food miles." The implications are obviously positive for commercial fruit and vegetable marketers. Here is an abstract for the research called "Food-Miles and the Relative Climate Impacts of Food Choices in the United States", by Christopher Weber and H. Scott Matthews.



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 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.


TK: Check out this thoughtful post at the Ethicurean blog for more analysis and reaction from local food fans.