There may be many reasons to eat locally: supporting your local economy, ensuring food freshness, curbing sprawl, or reducing unnecessary energy use. One of the most pervasive arguments in favor of the local food movement has been to reduce or eliminate the environmental impacts of long-haul food shipments. But Carnegie-Mellon researchers Christopher L. Weber and H. Scott Matthews suggest that, at least from a greenhouse gas (GHG) perspective, food miles may not be as important as you may think.
In their recent article entitled “Food Miles and the Relative Climate Impacts of Food Choices in the United States,” appearing in Environmental Science and Technology, Weber and Matthews conclude that “the distance that food travels only accounts for around 11 percent of the average American household’s food-related GHG emissions.” According to the authors, the more important factor in food-related GHG emissions is the amount of resources required to produce it.
The authors show that for the average U.S. household, “shifting less than 1 day per week’s consumption of red meat and/or dairy to other protein sources or a vegetable-based diet could have the same climate impact as buying all household food from local providers.” On average, they find, red meat produces more GHGs than any other form of food. So, while there are many reasons to support our local farms, there are also strong greenhouse gas reasons to be sure we eat our veggies, no matter where they came from.