Hauling Food Long Distances More Efficient than Buying Locally, New Study Claims

This story appears in the Nov. 23 print edition of Transport Topics.

Hauling food products, such as meat, eggs and dairy products, over long distances is more energy-efficient and less polluting than buying food from local growers, according to a new academic study.

“The desire to support locally-produced food is admirable,” said Dr. Jude Capper, assistant professor of dairy science at Washington State University in Pullman, Wash. “However, from an environment standpoint, local food has a considerably larger impact than food produced outside the local area and mass-transported across the country.”

The reason for that, according to a report presented at a feed manufacturers’ conference at Cornell University last month, is that it takes fewer resources and less energy to produce and ship food in large quantities.

The report takes aim at the concept of “food miles,” which is the distance food travels from its place of origin to its place of final consumption.

Many environmental groups and advocates of sustainable farming practices contend that moving food over long distances wastes energy and undermines local farm businesses.

“We are certainly seeing the trend of consumers buying more local products,” said Jim Lemke, senior vice president of C.H. Robinson Worldwide, Eden Prairie, Minn., a freight brokerage firm that also has a large produce sourcing business.

While consumers see value in supporting local communities and local farmers, Lemke said the sustainability issue “is complex” and that “a wide variety of supply chain efficiencies, such as economies of scale, transportation costs and distribution inputs, need to be taken into consideration.”

Rich Pirog, associate director of the Leopold Center for Sustainable Agriculture at Iowa State University, agreed that calculating food miles, by itself, “is not a good way to assess environmental impact.”

In 2001, Pirog published a report that helped to popularize the notion of food miles by analyzing the movement of fresh produce into Chicago.

“From a research perspective, we’ve moved on,” Pirog said. “We’re looking at life-cycle assessment, carbon footprint, water quality impact.”

Food miles, Pirog said, “[are] just a metaphor now for how local food is.”

In the report co-authored by Capper, researchers compared the carbon footprint of a dozen eggs purchased from a chain grocery store, a local farmer’s market and directly from a nearby poultry farm.

While the distance between the source and consumption point was greatest for the grocery store — 1,291 miles versus 138 miles for the farmer’s market and 44 miles to the local farm — the analysis showed that a tractor-trailer with a full load of eggs used far less fuel per unit of eggs than the alternatives.

A tractor-trailer that carries a load of 23,400 dozen eggs and also picks up a backhaul load will use 0.28 liter of fuel per dozen eggs, the report stated. Without a backhaul, fuel use nearly doubles to 0.56 liter per dozen eggs.

By comparison, a private car going to a farmers’ market will consume 2.39 liters of fuel to pick up a dozen eggs and more than 9 liters of fuel to retrieve a dozen eggs from a local farm.

While the eggs in this scenario were transported from California to a location in the Pacific Northwest, “eggs could be transported across the entire North American continent by the tractor-trailer, and the grocery store model would remain the most fuel-efficient, eco-friendly option,” the report said.

“It seems intuitive that if food travels 30 miles rather than 300 miles, it should have a lower environmental impact,” Capper said in an interview with Transport Topics. “This misconception has been picked up by blogs and news media and is accepted by the consumer as fact, but seldom holds up under scientific examination.”

The key to reducing environmental impact, according to Capper, is productivity.

“That is manifested as increased milk yield per cow, growth rate per beef animal or capacity per tractor-trailer,” she said.

Food producers also must consider how they affect the system, Capper said.

“Retailers have a tendency to take a narrow view by altering only those components that they understand,” she said.

A new cheese processing center that is moved to be closer to a grocery distribution center to reduce miles, for example, may cause loads of milk to travel farther, offsetting the savings.

“To avoid these types of negative trade-offs,” Capper said, “the whole system has to be considered, not simply individual components.”

Whole Foods Market, the nation’s largest natural and organic foods retailer, has committed $10 million in low-interest loans to farmers

to expand production of locally grown food.

Among the loan recipients are an organic vegetable farm in North Carolina, a heritage turkey grower in Pennsylvania and a grass-fed cattle ranch in Georgia.

Spokeswoman Liz Burkhart said Whole Foods believes that sourcing locally “meets community needs and environmental goals.”