Buying locally produced foods is the trend for those of us interested in reducing our carbon footprint and our impact on the environment. The theory is that buying local foods reduces energy use compared to buying food shipped across the country. Most produce is shipped, on average, 1500 miles from farm to market. Most people assume that the fewer miles produce travels to market, the less fuel used. However, researchers at Ohio State University's rural sociology program believe the impact on the environment may be less clear cut.
There may be some variables that make buying local less efficient when it comes to energy consumption. One of the factors involves economies of scale. A fully loaded tractor trailer can haul 38,000 pieces of produce. The energy savings of a loaded freight car on rail is even more. Compare the energy consumption per unit with that of dozens of pickup trucks hauling small loads of produce to farmer's markets and individual stores. Although the energy savings advantage is still in the local farmer's favor, is may be less than you'd think.
Another factor is the amount of energy used by the consumers of the produce. While going to a farmer's market offers many social and community building benefits, one stop shopping at a grocery store probably uses less gas than making multiple stops at various markets or going to a farmer's market or local farm to purchase just a few items.
The researchers still were in favor of supporting locally grown produce, but cautioned against assuming huge energy savings.
For more information on this paper, go to: Ohio State Extension.