farmers marketI’m all in favor eating local foods when possible, but I continue to be unimpressed with arguments that we could replace our industrial food supply with locally-grown products. The authors of this new study argue:

“If you drew a 100-mile circle around each city in the U.S. and then you looked at the capacity of the existing farmland, you’d find that 90 percent of the people could be fed within those circles,” says Elliott Campbell, an associate professor of environmental engineering at U.C. Merced who co-authored the study.

Even if we take this study at face value it seems flawed. I don’t have access to the original paper but if comments by other scientists are to be believed, the conclusion isn’t warranted by the evidence:

“They’re estimating how many calories silage and hay can be produced within a given radius of the cities,” Sexton says. “That’s fine if Americans are just consuming calories, but Americans consume food products.”

In other words, the study didn’t measure how many tomatoes, oranges, or cucumbers could be grown in a 100-mile radius of cities—it measures calories from cattle feed. While that might be a useful study for academic purposes it has no relation to real-world food consumption. The conclusion is just misleading. It should be palpably obvious that most regions in the country cannot grow food all year round and many foods cannot be stored over long periods. A winter diet of potatoes and beets might be virtuous but it will neither be tasty nor nutritious.

Moreover, there are many efficiencies that are gained by having regions specialize in what they grow best according to Steve Sexton with the Sanford School of Public Policy at Duke University :

The case for specialization is perhaps nowhere stronger than in agriculture, where the costs of production depend on natural resource endowments, such as temperature, rainfall, and sunlight, as well as soil quality, pest infestations, and land costs. Different crops demand different conditions and vary in their resilience to shocks.

There is a good case to be made for locavorism—when compared to industrial agriculture local food tastes better, it is usually more healthy, and there are good community-based reasons for supporting your local farmer. In other words, the argument is primarily an aesthetic argument—local foods give more pleasure.

So we should support locavorism where possible without rigidly insisting that our food supply be entirely local.