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With “food miles” becoming a hot catchphrase this past year, it’s only a matter of time before American consumers start talking about a food product’s carbon footprint.

So says Leopold Center Associate Director Rich Pirog. Pirog fields numerous inquiries each week about local food systems, with many citing his 2001 paper, “Food, Fuel and Freeways,” the first of three “food miles” reports published by the Leopold Center.

Life Cycle Assessment

The U.S. food industry has begun to apply Life Cycle Assessment, shown above for an industrial product, to determine environmental impacts in the food supply chain. [Illustration adapted and used with permission, Akzo Nobel]

Rather than tracking food miles – the distance that food travels from where it is grown to where it is sold – Pirog said many researchers have begun to take a more holistic approach to documenting the environmental impact of a food supply chain. A life cycle assessment (LCA) accounts for the environmental impacts of energy, materials and other inputs throughout a product’s lifespan. While cradle-to-grave product analyses are not new in the manufacturing world, only recently have they been applied in U.S. food production scenarios. Measuring the carbon footprint of total greenhouse gas emissions is a type of LCA that is focused solely on climate change impacts.

In his 2001 paper, Pirog employed a statistical methodology to calculate “food miles” and to determine the greenhouse gas emissions required to transport produce and other agricultural products to consumers. He found that the conventional system of transporting food used 4 to 17 times more fuel than Iowa-based regional and local systems, and released from 5 to 17 times more carbon dioxide.

Food miles, only part of story
“Food miles have been used as one of the arguments for eating locally grown foods, because the assumption is that lower food miles mean lower environmental impact,” Pirog said. “But when greenhouse gas emissions are the indicator used to look at environmental impacts, food miles are not a reliable indicator; you need to know the mode of transport, the fuel efficiency of the transport, and the emissions generated across the entire food chain.”

Pirog cited a recent Belgian study published in the Journal of Environmental Policy and Planning (March 2007) that showed greenhouse gas emissions in local food systems may, in fact, be higher than those found in a comparable conventional food system. The study points to the need for more research to compare greenhouse gas emissions and other environmental impacts in local versus conventional food systems.

Pirog recently participated in a three-day international symposium at the University of California-Davis to develop research strategies that would document and reduce greenhouse gases in food production. He was one of 20 researchers, government officials and food industry representatives from Europe and the United States invited to attend. The gathering will produce a white paper outlining U.S. priorities for policy, research, education and outreach regarding energy use and environmental impacts of food supply chains.

“The European Union already has carbon labels on foods and the first such labels likely will be introduced in the United States in the next year,” Pirog said, adding that he is reviewing carbon calculators for use in the public and private sector.

Five questions to answer
Pirog cites these as the most often asked questions about local foods:

• Are local foods better for the environment than food from conventional systems?

• Are local foods safer than conventional foods?

• Are local foods healthier than conventional foods?

• Are local foods better for the state’s economy and farmer profitability than conventional foods?

• Are local foods better for rural and urban communities than conventional foods?

“These are the top questions being asked, by news reporters, policy makers, investors and foundations,” he said. “From a research perspective, there is information to answer the questions about the economic and community benefits, but the questions regarding environment, safety and health benefits need more research.”

A number of players are getting into the local foods market, including worldwide retailer Wal-Mart. Pirog predicted that with headlines about food safety problems, rising fuel costs, global climate change, and consumer queries for information about how and where their food is grown, demand will continue to increase for local and regional food production.

The Symposium on Energy LCA of Food Systems was hosted by the UC-Davis Agricultural Sustainability Institute and the statewide Sustainable Agriculture Research and Education Program (SAREP) in California. Pirog joined representatives from the Bon Appétit Management Company Foundation that helped sponsor the symposium, plus the Department for Environment, Food and Rural Affairs (DEFRA) in the United Kingdom, the Danish Institute of Agricultural Sciences, Ecotrust, and a private energy company in Switzerland.