Fossil Fuel Use - Boats, Trains, Trucks, and Refrigerators

I've been investigating my assumption that buying local foods reduces fossil fuel usage, and the results so far are really interesting.

First, it depends on how the food is transported. Apparently, shipping by sea has been found to be far more polluting than previously thought (http://www.guardian.co.uk/environment/2008/feb/13/climatechange.pollution). The main culprit here appears to be that ships in international waters are poorly regulated, and so they use the cheapest, dirtiest fuel available. Purchasing kiwi shipped from Italy or New Zealand contributes far more to global pollution than purchasing kiwi from California (unless the Californian kiwi is transported by boat as well).

This report is supported by a study in Seattle that actually measured the amount of greenhouse gases released by essentially identical plates of locally- and internationally-produced foods. The locally-produced plate wins, hands down. The report is well summarized by Tim Crosby, who writes a fascinating blog on food systems in the U.S.

The results for transportation of domestic foodstuffs is more murky, perhaps because it's difficult to compare transportation of food in a semi from California to transportation by multiple consumers' cars. In Energy Use in the U.S. Food System: a summary of existing research and analysis, John Hendrickson argues that, while it's very difficult to determine the true cost of transporting foods, there are other good reasons to buy locally:

"Regardless of the actual miles or the relative proportion of energy used in transporting food products, it is important to realize that transportation is an especially vulnerable sector of the food system. In contrast to the other sectors of the food system, transportation is almost exclusively dependent upon liquid fuels derived from oil. International supply disruptions and price fluctuations can have a more marked and immediate impact on this sector (OECD 1982). And this vulnerable sector is, experts agree, the most critical sector of the food system. What the modern food industry hails as the “global supermarket” depends heavily on cheap and efficient transportation. Without cheap and efficient transportation, there can be no “global supermarket.” Subsidies in this sector (highway maintenance for example) are significant and help keep food affordable for the average American. If fuel were priced so as to reflect its true costs (including environmental impacts) food prices would rise accordingly. Already, 6-12 percent of the consumer dollar spent on food eaten at home represents transportation costs (Rhodes 1993). True-cost pricing for gasoline has been estimated at $4.50/gallon by the Worldwatch Institute (1989). Another study has suggested an increase of over two dollars (World Resources Institute 1992). These and other considerations have led many analysts of the food system to suggest at least a partial return to a more decentralized system of distribution, in which individual states and/or regions are more self-reliant in food (Tansey and Worsley 1995; Kloppenburg et al. 1996). See Paxton (1996) for a review of the environmental and social consequences of long distance food transport."

I also discovered, much to my surprise, that transportation is only the second largest source of energy consumption in the U.S. food system (not including the cost of producing the food in the first place, which is far, far more energy-intensive than transporting the food). According to Swivel.com, transportation accounts for 14% of energy consumption, but 35% of energy consumption is caused by home refrigeration! This is making me rethink getting a standing freezer to store more food. Who could have guessed that how we store our food is more important than how we get it in the first place?