This Opinion/Editorial was featured in The Wall Street Journal.

The effort to re-localize agricultural production in the U.S. is becoming a real food fight.

While localvores—people who try to eat and shop locally—rarely cause actual street fights, science suggests the local-foods movement could actually threaten the environmental and human health objectives that inspired it.

Prevailing wisdom among localvores holds that shortening the distance food travels from “farm to fork” diminishes environmental impact by reducing fuel used for shipping. But transportation accounts for 10% or less of the energy used to bring food to market.

Farm operations account for a far greater share of total energy use. Food should be grown on lands that have the right soil and climate and face minimal threats from pests. California produces more than 90% of all strawberries grown in the U.S., and so it should. It is more than five times more efficient than the next best state.

It would take Michigan 14 acres to grow the strawberries California produces on a single acre. Fortunately, Michiganders only plant about 1% of total strawberry acreage in the U.S. They grow a plurality of squash, however, boasting the highest output per acre of any state, 20% higher than California.

Local food production would sacrifice the advantages California, Michigan and other states have in producing particular crops. Lower yields require more fuel, fertilizer, pesticides, and herbicides to compensate for suboptimal growing conditions. Further, high yields from modern farming have allowed cropland to return to natural habitat. Low yields from local production would upset this positive trend.

By our estimates, at least 60 million additional acres of farmland—an area the size of Oregon—would be required to locally produce 40 crops at current yields. Local corn grain production, for example, would require 27% more land, 35% more fertilizer, 23% more chemicals and fuel than current production. This would also reduce forage for honeybees, contributing further to their decline.

This would raise the cost of food, undermining efforts to improve American diets. The cost to overcome poor, local growing conditions that cause low yields are greatest for precisely the healthy foods that our dietary goals demand become cheaper.

Americans intuitively understand the gains from specialization and trade, which is why most of us choose to work in one job rather than several. Perhaps nowhere are these gains greater than in agriculture, where natural resource endowments figure centrally. Though feel-good notions of buy local are tempting, we shouldn’t abandon modern farming for local production when the costs of less-efficient food production are so great.

As an economist who as a child worked on the family farm, and a beekeeper with close ties to the local farming community, we enjoy farmers’ markets and the taste of fresh-picked seasonal produce.

But science suggests the local foods movement is unlikely to improve the sustainability or nutrition of our diets while risking solutions to the global environment and human health.

Todd Myers (@WAPolicyGreen) is the environmental director at Washington Policy Center in Seattle and author of “Eco-Fads: How the Rise of Trendy Environmentalism is Harming the Environment.” He also serves on the Puget Sound Salmon Recovery Council. Steven Sexton is an assistant professor in the Sanford School of Public Policy at Duke University.