Despite its immense popularity, it doesn’t yet have a common name: some call it “locavorism,” others “localism.” In terms of clarity, the compound “eating locally” may be best.

But if opinions differ on nomenclature, everyone pretty much knows what it is: buying food from local producers. Virtually every town that boasts a crossroads and a gas station now has a farmer’s market. Restaurants trumpet their local vegetables, meat, and fungi. Food writers wax ecstatic over the delicacy of lamb raised on local herbage, the sweetness of halibut hauled from local waters, the crispness of a radish plucked from the local loam.

Eating locally is nothing new, of course. What is new—relatively—is the global commoditization of food, the labyrinthine complex of trade policies, modern farming techniques, and transportation infrastructure that allows us to eat raspberries in January, persimmons in August, and oysters year-round. And though developed countries call on the world to fill their dinner plates, many if not most people in Asia and Africa—and large portions of South America—still eat wholly from local sources. They have to; eating locally is a necessity rather than a civic virtue. North American food localism, however, is often a matter of choice: a response to commoditized food widely perceived as lacking in flavor and nutrients.

Localism also has a strong environmental component. Environmentalists reflexively support local eating, claiming it reduces fuel consumption and atmospheric carbon loading. Not always so, says Maisie Greenawalt, vice president of Bon Appétit, a Palo Alto–based food service management company that endeavors to buy at least 20 percent of its food from local producers. “For carbon reduction, local isn’t necessarily the answer,” Greenawalt says, “especially where meat and dairy products are concerned.”

A 2006 report from the Food and Agriculture Organization of the United Nations concluded that livestock accounted for 9 percent of the carbon dioxide, 37 percent of the methane, and 65 percent of the nitrous oxide that come from human-associated activities. All three gases contribute to global warming; methane and nitrous oxide are more potent greenhouse gases than CO 2 . “So whether your steak comes from Argentina or the rancher down the road, it is, relatively speaking, a high-carbon food,” Greenawalt notes. Further, says Greenawalt, the mode of transportation is more germane than distance in determining the carbon impacts of moving food around. “Air freight produces about 11 times the amount of atmospheric carbon as commercial shipping,” Greenawalt says. “So the literal slow boat from China is better environmentally than a jet plane shuttling produce from California to New York.”

Still, says David Zilberman, a professor of agriculture and resource economics at UC Berkeley, the advantages of local food are real—most pertinently, simple sensory pleasure. “Fresh food from nearby sources is, in fact, fresh,” says Zilberman. “It tends to smell and taste better.”

Greenawalt likewise emphasizes the basic good taste of local food. “Food can’t be bred to travel well,” she says. “There is no way industrial food services can transport heirloom tomatoes at their peak of ripeness and flavor, for example. If you want to eat them, you have to buy them from a nearby farmer.”

Greenawalt points out that robust local food systems strengthen communities, bonding people to their fellow citizens and surrounding landscapes. “There’s a multiplier effect,” she says. “Local food production creates jobs. It re-invigorates languishing downtowns through farmer’s markets. It preserves green space around urban cores, and it provides educational opportunities to children, who get a chance to see working farms.”

And though it may be honored more in the breach than the observance—plenty of New Zealand orange roughy, Chilean asparagus, and soda infused with Iowan high-fructose corn syrup are still consumed across the country—Americans now generally acknowledge the wisdom of eating locally. In an article that cited surveys on attitudes toward food, John Ikerd, professor emeritus of agricultural economics at the University of Missouri, noted that 73 percent of Americans want to know if food is produced locally; 75 percent of consumers in Seattle, Boston, and seven Midwestern states prefer food produced by local family farmers; and 70 percent of households in Wisconsin, Missouri, Nebraska, and Iowa consider the consumption of local foods and the support of local farms “extremely important.”

U.S. locavorism has its roots in the organic agriculture movement. But as organic food has evolved from an artisanal rural endeavor to a multi­billion-dollar industry, locavores have detached themselves. Local foods may not all be organic, but they are considered by their advocates to be superior, given that fruits and vegetables conform to the seasons and are picked at peak ripeness, and meat animals can be raised on pasturage rather than vast feed lots. The real prime mover of U.S. local eating is Slow Food, an enterprise begun in Italy in the mid-1980s. Slow Food promotes local production, food that does not harm “the environment, animal welfare or … health,” and a general commitment to “eco-gastronomy.” Progressive chefs, restaurateurs, and foodies in the United States embraced the Slow Food manifesto, and the concept gained some credence among the general public through the 1990s.

But locavorism’s breakthrough moment didn’t come until 2006, with the publication of The Omnivore’s Dilemma by Berkeley Knight Professor of Journalism Michael Pollan. The bestselling book traces the provenance of four meals, including one derived from the agribusiness complex and one from a remarkable farm in Virginia that utilized complex pasture rotations and extensive composting to produce a wide array of foodstuffs—all derived, either directly or indirectly, from grass. Pollan—who declined an interview request for this article—is a compelling writer, and his prose captured both the stench of the feedlot and the sweet smell of lush pasturage. The benefits of eating food produced by local farmers with both an environmental ethic and a commitment to consumers were never made so viscerally explicit.

Pollan also supports the notion that local food—particularly local organic food—can be far more nutritious than commercially produced food. In Defense of Food, his follow-up to The Omnivore’s Dilemma, cites research comparing foods grown organically to those grown conventionally; the organic food, he says, contained “appreciably higher levels of antioxidants, flavonoids, vitamins, and other nutrients…. Of course, after a few days riding cross-country in a truck, the nutritional quality of any kind of produce will deteriorate, so ideally you want to look for food that is both organic and local….”

But while locavorism has achieved media saturation across the developed world, its application remains resolutely—well, local. By its very nature, it must remain a weak confederacy, a loose network of like-minded people who agree in principle, then cultivate their own gardens in their own places. The question is: Can local food feed the world?

Maybe not—at least, not the world as currently configured, in which billions of people live in areas where they cannot readily produce all the food they need. “Food” in the locavore doctrine generally means high-quality fruits and vegetables, specialty meat and seafood, and artisanal comestibles: cheeses, breads, charcuterie, conserves. Staples, such as they are, tend to come in the form of heritage potatoes or exotic legumes.

But “food” for a significant portion of the world consists largely of grains—corn and rice, principally—and soybeans. Much is used for livestock feed or processed products, but some is eaten directly, particularly in Africa, where famine relief is a perennial necessity. These base foodstuffs are loaded by the kiloton into ships and transported across the world where and when they are needed. The system that yields this abundance has its flaws, acknowledges Brian Wright, professor of resource economics at Berkeley, but it fulfills its primary mission admirably: staving off global famine.

The United States remains the keystone of this planetary enterprise: The country’s estimated 2009 harvest for corn and soybeans stands at 12.9 billion bushels and 3.32 billion bushels, respectively, with most of that yield coming from the Midwestern grain belt. “The fact is that certain regions are the best places to grow certain crops,” says Wright. “And for growing corn and soybeans in quantity—the kind of quantity you need to feed billions of people—no place is better than the American Midwest. The soils and the climate are ideal, the infrastructure has been developed to accommodate that kind of economic activity, and people there know what they are doing.”

In econo-speak, this is an example of “comparative advantage,” Wright says: different regions doing what they do best to the exclusion of less-profitable pursuits. “You see the same thing in Alaska, where the food-producing portion of the economy is geared to fisheries, or Sri Lanka, which focuses on spice production.”

Although comparative advantage allows different regions to produce large quantities of different types of food, another element is required to provide the world a reliable and varied diet: modern shipping. “Because ships these days are so large, transporting commodity staples is incredibly cheap. The shipping industry has addressed the historic primary cause of famine—food availability.”

Wright explains that past famines often have occurred in areas where food was nearby; but poor access made it impossible to move it to where it was needed. “In medieval Europe, famines occurred 20 or 30 miles from areas where there was food in abundance,” he said. In the 21st century, “famines only occur in areas where there is difficult port access. There are no famines on island nations, with the exception of famines that are the result of political issues. People only go hungry these days in landlocked areas with poor roads—areas where it is still difficult to move food around. We now have the technology to rapidly ship enough food to literally feed nations.”

Some analysts feel this ability will not be with us much longer. Jeff Rubin, a Canadian economist known for his accurate predictions of petroleum prices, has opined that oil will hit $225 a barrel by 2012. This, says Rubin, will spell the end of globalization. Most people will be forced to eat locally; imported food will be astronomically expensive.

Wright agrees that oil may well hit triple digits in the next few years, but he doesn’t think expensive bunker fuel will becalm the great ships transporting food around the globe. “Food will undoubtedly get more expensive as world petroleum prices rise,” he says, “but it’s not going to get so expensive that global trade in food stops. Even with oil doubled, we won’t see much of an impact. Fuel transportation costs are a relatively small part of the expense involved in producing and moving food.” In other words, the economies of scale offered by the number and size of ships in the global fleet will make it remain practical to transport corn from the American Midwest, coffee from Central and South America, mutton and lamb from Australia.

Modern shipping doesn’t simply assure quantity, says Wright. It also guarantees generally good quality control. With the exception of stone fruits, “refrigerated and climate-controlled containers have made it possible to deliver very large quantities of other fruits and vegetables in good condition. And people will continue to want produce that is out of season, the virtues of local eating notwithstanding.”

One of those people is Anthony Fisher, professor of agricultural and resource economics at Berkeley. “I enjoy eating two navel oranges every morning,” Fisher says. “Whenever possible, I prefer oranges from California—their taste is excellent. But in the summer, when the oranges are out of season in the state, I buy oranges from the southern hemisphere. Without global trade, I wouldn’t derive the enjoyment and nutritional benefit I get from oranges for much of the year.”

Fisher notes his personal proclivity is manifested exponentially around the world. “If you are determined to eat locally in South Dakota or northern Germany, you’re going to be eating a lot of potatoes, parsnips, and kale in the winter, and not much else,” he says. “From the local perspective, our winter eating is greatly restricted even in California—people who participate in subscription programs with local growers know that.”

It would also be difficult for local producers in the United States to meet consumer demand on their own, Fisher says. “Between 70 [and] 80 percent of our fish and shellfish is imported,” he says. “For fruit and vegetables, the figure is between 30 [and] 40 percent. This food contributes significantly to our health and our quality of life. The consumer is not necessarily better off if his or her diet is restricted to local sources only.”

Greenawalt says locavorism can be “scaled” upward, but that such endeavors nevertheless involve hard choices and intractable limits. “We were very interested in the idea of sourcing our restaurants completely from local producers, so we did a study with Columbia University and MIT with one of our cafés at Hamilton College in Clinton, New York,” says Greenawalt. “We didn’t want to focus on a venue that is relatively easy to supply year-round, such as a college in California. Upstate New York is more challenging—the growing season is much shorter.”

The café served 1,500 students, says Greenawalt, and the project determined that they all could indeed be fed year-round solely from local sources—though they admittedly would eat a lot of root vegetables in January and February. But there was a larger problem than dietary monotony.

“While it was clear that it was possible to feed them 100 percent from local producers, it also became clear that we would strip the entire region of local food if we did that,” Greenawalt says. “In other words, nobody else from the area would be able to buy locally if the café became the priority for suppliers. Obviously, that wasn’t something we wanted to support. So can local food be scaled? Yes—but you have to talk about the appropriate level for that scale.”

There’s also, Fisher says, a social justice issue implicit in the promotion of local eating. Many undeveloped countries rely on food exports to developed countries to maintain rural living standards. If markets in the United States or Europe were to close through either mass shifts in consumer preference or legal fiat, it could prove disastrous for millions of poor farmers and agricultural workers in the Southern Hemisphere.

Zilberman says he prefers to characterize the situation as a matter of economic fairness rather than social justice. But he agrees with Fisher that food exports are essential for many developing countries. “They very much need to sell food for foreign exchange, and we should be open to that,” Zilberman says. “Not only does it provide our consumers with greater choice and better nutrition—it’s an issue of reciprocal trade. We export our computers, tractors, and other technological products; we need to be open to the products other countries are able to market.”

But a food production and purveyance system based on a localist model could have problems, he says, beyond reduced seasonal food variety. “We did a study on people who use pesticides most inefficiently—in other words, use them too much, too often, or at times and in places where they’re not recommended,” Zilberman says. “What we found is that the worst offenders aren’t commercial farmers—they’re home gardeners. One of my worries about a broad-based local food system is that too many amateurs would get into it. Yes, a significant portion of the food would be organic—but a significant portion wouldn’t. That could have a major negative environmental impact.”

Nor is it definitive that local food is healthier food, at least in a context that is global and cuts across all income levels. As Pollan noted, organic local food may contain more nutrients than food grown conventionally and transported long distances; but in a hungry, populous world, achieving the optimum isn’t always possible. Generally speaking, quality control probably is more important than provenance in the gauging of “healthy” food, says Fisher. For example, fungi- contaminated grain—which can cause a variety of diseases—remains a big problem in parts of the world where most food is produced and consumed locally.

Localism may be the right thing to do for a number of reasons, but it is problematic for several reasons. And one of them stands out: Just like the heart, the stomach wants what it wants. And what it wants, it appears, is a variety of foods, in quantity, at all times of the year.

“Under Mao, China had a long-standing policy that every region should be self-sufficient in food production,” says Wright. “This was a national security issue, and from that perspective it may have made sense—but it was a tremendous drag on productivity, and it had severe impacts on food availability and human health. When the policy was reversed in 1978, productivity boomed. Food of all varieties became much more available all across China. Localism—at least, enforced localism—didn’t serve the Chinese well.”