Is local food really miles better?

Many of us now count "food miles." But local fruits and veggies may not be more carbon-friendly than produce at the supermarket.

By Roberta Kwok

Read more: Life, Eat and Drink, Food and Travel

June 24, 2008 | When I arrive at San Francisco's Ferry Plaza Farmers Market on a gray Saturday morning, I do my best to ignore the food. It's not easy. There are mandarin oranges, fresh eggs, piles of perky greens and samples of everything from goat cheese to dried kiwi. But I'm not here to eat; I'm here to hunt for numbers.

A few weeks earlier, I noticed a page on the market's Web site that asks, "How Far Does Food Travel to Get to Your Plate?" Too far, it concludes. According to a 2001 study by the Leopold Center for Sustainable Agriculture, the average apple travels 1,555 miles to a Chicago terminal market where wholesalers sell produce to grocery stores. A San Francisco Farmers Market apple, on the other hand, only travels about 105 miles to the Ferry Plaza market building.

The Web site relies on the concept of "food miles," or the distance that food travels from farm to consumer. A new breed of eaters has embraced the local, low-food-mile diet. The Bay Area-based Locavores group, for instance, vows to eat food produced within 100 miles of San Francisco. In a nod to the movement's growing popularity, the word "locavore" nabbed the title of 2007 Word of the Year from the New Oxford American Dictionary, and Food and Wine magazine offers tips to befuddled cooks on "How to Eat Like a Locavore." Campaigns such as "Local Food Is Miles Better" (run by the trade magazine Farmers Weekly in the United Kingdom) have called on supermarkets to crack down on excessive food miles by labeling and promoting locally produced items. The corporate world has jumped on board as well: Google's Cafe 150 stocks its pantry with ingredients gathered from within a 150-mile radius.

While locavores list numerous reasons for eating local -- including freshness, taste and boosting regional economies -- one primary argument is protection of the environment. Long-distance food transport sucks up more fossil fuels, says the Farmers Market Web site, and unleashes more carbon dioxide onto our planet.

That does sound dire. But what if conventional distributors make up for the long journeys by driving big trucks packed with produce? Let's say a distributor travels 1,000 miles and carries 1,000 apples to market, while 10 local farmers each drive a pickup 100 miles and carry 100 apples each. The local farmers log fewer food miles but cover the same total distance -- and use a comparable amount of fossil fuels -- for the same amount of food.

Vehicle types and packing likely make a difference, says Richard Pirog, associate director of the Leopold Center for Sustainable Agriculture, and lead author of the food miles study. "I bet you dollars to doughnuts that at your San Francisco Farmers Market, the farmers don't pull up in semi-trailers," he says.

He's right. After surveying 19 farmers on my Saturday visit, I found that most of them drove Ford, Isuzu or Chevrolet trucks, packing anywhere between 200 and 2,000 pounds of goods. While some were hanging onto late '90s models, one proudly sported a new fuel-efficient Dodge Sprinter. They'd trucked their wares an average of 117 miles, with farms ranging from nearby Bolinas to the 230-miles-distant town of Exeter in the Central Valley.

Not surprisingly, conventional distributors such as Banner Fruit Co. range farther afield. According to a survey of nine wholesalers at the Golden Gate Produce Terminal in South San Francisco, their produce comes not only from California but Arizona, Washington, Texas and Mexico, with distances from farm region to market averaging 942 miles. These distributors supply produce to small- and medium-size grocery stores in the region, including Whole Foods and Mollie Stone's; large chains such as Safeway and Costco manage their own distribution systems. They use semi-trailer trucks that can pack more than 40,000 pounds of food -- about 20 times the largest load hauled by a farmer.

But how does that translate to carbon dioxide emissions? To find out, I crunched the numbers on five types of produce -- apples, oranges, lettuce, greens and squash -- with fuel efficiency estimates from the Environmental Protection Agency and Bay Area truck dealers. Factor in carbon emission figures from Argonne National Laboratory, and I had rough carbon footprints for each farmer and wholesaler.

Local farmers won one category, proving more carbon-friendly on squash. While farmers came from cities about an hour's drive from San Francisco, wholesalers had imported their squash through Arizona from Mexico. In these cases, the idea that more food miles equals more fossil fuels appeared to be true.

But wholesalers beat local farmers on the four other produce items, boasting fewer average carbon dioxide emissions per pound of apples, oranges, lettuce and greens. Apple distributors got almost all their apples from Washington's Yakima Valley, about 700 miles away. (Safeway's California stores get Granny Smith apples from Stockton during fall and winter, and from Washington the rest of the year.) While the two local apple farmers traveled one-tenth the distance, their loads averaged less than 700 pounds -- and generated six times more carbon dioxide per pound of apples than the semi-trailer trucks.

Local oranges didn't fare much better. Part of the reason is that "conventional" oranges are local, too. Distributors shipped most of their oranges from California's Central Valley, a mere 200 miles from San Francisco and the home of several farmers market vendors. Conventional lettuce and greens came mainly from Arizona and also produced less carbon dioxide during transportation, though by a smaller margin.

Next page: Had I missed some hidden carbon costs?