The wisdom of eating locally, at least as it applies to the supply chain, is contested by Roger A. Cady, Ph.D., senior technical consultant at Elanco, which develops and markets products to improve animal health and protein production.
Cady is co-author of the recent report, "Demystifying the Environmental Sustainability of Food Production," which suggests that buying food from grocery retailers who are part of the modern transportation network is more energy efficient and environmentally beneficial than buying from local sources like farmer's markets.
The report explains that linear travel miles are not indicative of total energy use and therefore not necessarily a valid measure of the environmental impact of moving food over long distances. Instead of total miles traveled, the report states that the energy use per unit of food moved paints a more accurate picture of overall energy use. The report found that a modern refrigerated tractor-trailer uses the least amount of fuel per dozen eggs while en route to a grocery store, even if the eggs travel hundreds more miles than would eggs traveling from a local farm to a farmers market or to the consumer's home. Fuel consumption per dozen eggs purchased from a farmers market is more than eight times the amount used by tractor-trailer. A consumer traveling to a local poultry farm is even less fuel-efficient.
