Which is greener: buying local, or buying organic?

BBC News today reports on a British study that stakes out a clear position on the issue:

Local food is usually more "green" than organic food, according to a report published in the journal Food Policy.

The authors say organic farming is also valuable, but people can help the environment even more by buying food from within a 20km (12-mile) radius.

They calculate that moving food long distances can cause more harm than non-organic farming methods.

As we’ve notedbefore, the "organic" label is clearly not synonymous with "sustainable." To be sure, there are lots of good personal and environmental reasons to choose organic food; for one, people who eat organic ingest less pesticides. (For example, University of Washington researcher Richard Fenske and his colleagues have shown that kids who eat organic have lower levels of pesticides in their urine.)

But the consequences of long-distance transport—including greenhouse gases and toxic releases from vehicle exhaust—can be at least as troublesome as the impacts of chemical-intensive farming.   

So if you’re looking to minimize the environmental consequences of your food choices, your best bet is to choose food that’s both local and organic.  But if you have to choose between the two, there’s at least one study that says that buying local is the gentler choice.