NEWS

Findings by Christopher Weber and H. Scott Matthews of Carnegie Mellon University in Pittsburgh, Pa., who compared the greenhouse gas emissions caused by producing and transporting various categories of food in the United States indicate "If you're looking across everything that you're eating, the type of food that you're choosing matters a lot more than where it comes from."
The pair found in 2008 that transporting food from the farm or production site to the store contributed only 4 percent of the total greenhouse gas emissions in the U.S. food supply, while producing the food accounted for 83 percent. Since production dominates, choosing categories of food whose growth and processing release less greenhouse gas can make a bigger difference than becoming a strict locovore, they report.

The team found that a majority of food's climate impact is due to non-CO2 greenhouse gases.Dairy products come in second in greenhouse impact in most of the team's analyses, since they also come from cows. Cereals and carbohydrates; chicken, fish and eggs; and fruits and vegetables were similar to each other in their contributions.

Of course, if you are already eating mostly veggies and grains, cutting out the transportation component by choosing local food won't hurt.However, Weber cautioned, other studies have looked at the greenhouse gas impacts of individual foods like tomatoes and apples and found that long-term refrigerated storage or greenhouses may be required for even local supplies, which may create energy demands that balance or exceed that needed to transport the same foods from friendlier climes.