Dietary choice, not the distance it takes for food to go from farm to plate, is more important for lightening the carbon footprint, say researchers at Carnegie Mellon. While recent buzz has maintained that “food miles” impact the environment, Christopher L. Weber and H. Scott Matthews contend that what we eat means more in terms of climate impact. Weber, a research professor, and Matthews, an associate professor, are with the university’s department of civil and environmental engineering and engineering and public policy.

 

"Our analysis shows that despite all the attention given to food miles, the distance that food travels is only around 11% of the average American household's food-related greenhouse gas emissions,'' said Weber publicly of the results, which will appear in an upcoming article in Environmental Science & Technology.

 

Food production, say Weber and Matthews, makes a greater impact through the amount of non-energy based greenhouse gas emissions than do trucks that travel, on average, 4,000 to 5,000 miles to transport food. The meat and dairy industries, the researchers maintain, are responsible for the heaviest carbon footprints, far more than petroleum-based transport miles.

 

While the report applauds eating locally, the authors suggest that eating less red meat and dairy may be a more effective way to reduce the impact. Shifting to a wholly local diet, say the researchers, would reduce the equivalent greenhouse gas emissions as driving 1,000 miles, but the greatest benefit would start with dietary changes.

 

"Where you get your food from is a relevant factor in family food decisions, but what you are eating—and the processes needed to make it—is much more important from a climate change perspective,'' said Matthews publicly.

 

Just switching one day’s worth of meat and dairy-based calories per week to chicken, fish or vegetables, explain Weber and Matthews, would have the same impact as eating locally entirely. If one’s diet includes no meat or dairy, shifting to a vegetable-based diet, the reduced emissions would equal 8,000 food miles per year.

 

Jill Buck, founder of the environmental educational organization Go Green Initiative, based in Pleasanton, CA, commends the researchers for conducting the study. “I thought the study was great on a number of levels. The researchers make an excellent point about the meat issue, and following their advice would be an excellent choice,” Buck said.

 

A particular point on which Buck would like people to focus is the myriad benefits of buying locally-grown goods. “I would have liked for the researchers to mention that buying locally tends to make people more invested in clean soil and clean water,” she adds. “When people buy locally, they want to make sure that their soil and water are clean—buying locally puts people in closer contact with how food grown locally affects them.”

 

Shopping locally creates what Buck describes as a “panoramic benefit,” in which several positive social, economic, and environmental issues improve. “When people buy locally, they are proud to support their local economy and the growers. Sometimes we feel disconnected, and as a result we don’t care about the local environment,” she explains. “If we know the food is being grown locally, we’ll take note of how fresh things are, if they are organically grown, and, for example, we will want to prevent drought conditions to ensure enough water to grow the foods we eat."

 

This creates a direct relationship between the environment and what we eat, Buck explains. “This is a very real effect of consuming locally grown food. There is an increased motivation to protect the local food supply when that is what people are consuming.”

 

“This is why people go to farmer’s markets. It makes people feel good to buy from local farmers, support the local economy, and creates a sense of community. Let’s expand that to grocery stores,” Buck maintains. “People connect, and it goes back to that old-fashioned way of doing things, like we did before the 1950s. It actually becomes a form of civic engagement.”

 

 

For more information on Go Green Initiative, go to www.gogreeninitiative.org.