When local is worse...

Part of the new intuitive, agrarian approach to food may fail the test of simple mathematics. The local food movement derives legitimacy in large part from the seemingly obvious merit of food traveling fewer miles. Except it likely travels those miles very inefficiently.

But a gathering body of evidence suggests that local food can sometimes consume more energy -- and produce more greenhouse gases -- than food imported from great distances. Moving food by train or ship is quite efficient, pound for pound, and transportation can often be a relatively small part of the total energy "footprint" of food compared with growing, packaging, or, for that matter, cooking it. A head of lettuce grown in Vermont may have less of an energy impact than one shipped up from Chile. But grow that Vermont lettuce late in the season in a heated greenhouse and its energy impact leapfrogs the imported option. So while local food may have its benefits, helping with climate change is not always one of them. [More]

Local food of course has other valuable attributes: freshness, taste, uniqueness, etc. And the market can value them with consumer input. But claims of greenhouse gas emission reduction need some real numbers.

[via Free Exchange]