Executive Summary

Most consumers do not understand today's highly complex global food system. Much of the food production and processing occurs far away from where they live and buy groceries. External environmental and community costs related to the production, processing, storage, and transportation of the food are seldom accounted for in the food's price, nor are consumers made aware of these external costs. Examples of external environmental costs are the increased amount of fossil fuel used to transport food long distances, and the increase in greenhouse gas emissions resulting from the burning of these fuels.

Local and regional food systems, where farmers and processors sell and distribute their food to consumers within a given area, may use less fossil fuel for transportation because the distance from farm to consumer is shorter. This paper discusses transportation from farm to point of sale within local, regional, and conventional food systems. Using fresh produce and other foods as examples, we considered miles traveled, fossil fuels used, and carbon dioxide emissions, and assessed potential environmental costs.

A food mile is the distance food travels from where it is grown or raised to where it is ultimately purchased by the consumer or end-user. A Weighted Average Source Distance (WASD) can be used to calculate a single distance figure that combines information on the distances from producers to consumers and amount of food product transported. U.S. Department of Agriculture Agricultural Marketing Service produce arrival data from the Chicago, Illinois terminal market were examined for 1981, 1989, and 1998, and a WASD was calculated for arrivals by truck within the continental United States for each year. Produce arriving by truck traveled an average distance of 1,518 miles to reach Chicago in 1998, a 22 percent increase over the 1,245 miles traveled in 1981.

A WASD was calculated for a sampling of data from three Iowa local food projects where farmers sold to institutional markets such as hospitals, restaurants, and conference centers. The food traveled an average of 44.6 miles to reach its destination, compared with an estimated 1,546 miles if these food items had arrived from conventional national sources.

Would there be transportation fuel savings and reduction in carbon dioxide (CO2) emissions if more food were produced and distributed in local and regional food systems? To answer this question, we calculated fuel use and CO2 emissions to transport 10 percent of the estimated total Iowa per capita consumption of 28 fresh produce items for three different food systems. A number of assumptions were used regarding production origin, distance traveled, load capacity, and fuel economy to make the calculations. The goal was for each of the three systems to transport 10 percent by weight of the estimated Iowa per capita consumption of these produce items from farm to point of sale.

The conventional system represented an integrated retail/wholesale buying system where national sources supply Iowa with produce using large semitrailer trucks. The Iowa-based regional system involved a scenario modeled after an existing Iowa-based distribution infrastructure. In this scenario a cooperating network of Iowa farmers would supply produce to Iowa retailers and wholesalers using large semitrailer and midsize trucks. The local system represented farmers who market directly to consumers through community supported agriculture (CSA) enterprises and farmers markets, or through institutional markets such as restaurants, hospitals, and conference centers. This system used small light trucks.

The conventional system used 4 to 17 times more fuel than the Iowa-based regional and local systems, depending on the system and truck type. The same conventional system released from 5 to 17 times more CO2 from the burning of this fuel than the Iowa-based regional and local systems.

Growing and transporting 10 percent more of the produce for Iowa consumption in an Iowa-based regional or local food system would result in an annual savings ranging from 280 to 346 thousand gallons of fuel, depending on the system and truck type. The high end of this fuel reduction would be equivalent to the average annual diesel fuel use of 108 Iowa farms. Growing and transporting 10 percent more of the produce for Iowa consumption in an Iowa-based regional or local food system would result in an annual reduction in CO2 emissions ranging from 6.7 to 7.9 million pounds, depending on the system and truck type.

These fuel savings and CO2 reductions may seem small when considering total fuel use and CO2 emissions in Iowa, but our estimates represent less than 1 percent of total Iowa food and beverage consumption by weight (not including water). If a higher percentage of other foods and beverages were grown and/or processed in Iowa, the reduction in fuel use and CO2 emissions from food transport would undoubtedly be much greater.

This paper shows that fresh produce transported to Iowa consumers under the current conventional food system travels longer distances, uses more fuel, and releases more CO2 than the same quantity of produce transported in a local or Iowa-based regional food system. Given that fuel expenses are only a small percentage of total transportation and distribution costs, however, fuel energy costs will need to rise significantly if they are the only factor considered in determining whether local and regional systems are economically competitive with the conventional system. Economic value must be assigned to the external environmental cost of burning more fossil fuels and releasing more CO2. The authors strongly urge that more baseline research be conducted comparing the energy efficiency and external environmental costs of production, processing, packaging, and transportation sectors of conventional, regional, and local food systems.