This project examined the greenhouse gas emissions associated with various types of food. “Food-miles” refers to how far a product has traveled from its source to the consumer, including through processing stages. Their research question can be summarized as: What are the “GHG emissions associated with the production, transportation, and distribution of food consumed by American households”? The results of this study come from a model that is based on economic demands and the kilometers traveled through chains of custody for various types of food. Data on food demand came from the USDA. The second type of data was obtained from public records from the U.S. Commodity Flow Survey, and roughly converted to carbon dioxide emissions per dollar spent, based on fuels and transportation type used (truck versus ship, for example). Their models yielded results for several aspects of production and consumption, such as the amount of a product consumed per household per year, and the emissions of carbon dioxide per dollar spent. To put it simply, grains, fruits and vegetables were consumed in greater quantities overall, so require more transportation per household, but red meat and dairy products show extremely high emissions per unit consumed. Even though their models made some very broad assumptions concerning nationwide consumption, the results show such intense differences for certain food groups that the researchers concluded that choice in types of food has just as much of a climate impact as choice to buy locally produced food.

Weber, C. L., Mathews, S. (2008). Food-Miles and the Relative Climate Impacts of Food Choices in the United States. Environmental science and technology, 10, (42) 3508–3513.             Retrieved at http://mmm.comuv.com/wordpress/wp-content/uploads/2010/06/Food-       Miles-and-the-relative-impacts-of-food-choices-Weber-and-Matthews-2008.pdf