Day 13(a): Environmental downside of local food?

Produce from a Community Supported Agriculture program in Flagstaff, AZ

Buying locally is romantic. It feels good to support local economies, and reducing the carbon footprint of our food shopping habits is a noble goal.

But now, new research is adding a wrinkle. David Coley from the University of Exeter in the United Kingdom is lead author on a new study showing that, on average, lower carbon emissions result from delivering a vegetable box than making a trip to a local farm shop. The paper is out this week in the journal Food Policy.

I’m not sure how many people live where produce delivery is available — I don’t. But the study makes an interesting point.

Coley and his co-authors compared trips to a local farm shop with deliveries made by companies that distribute organic vegetable boxes to their customers. They found that if the average car journey made to a farm shop is a round trip of more than about 4 miles, then home delivery is a greener option even if the competing farm shop uses no lighting, heating or refrigeration. While a delivery van will travel up to 220 miles to deliver an organic vegetable box, the trip covers a large number of addresses — so the carbon emissions per customer will be surprisingly low, they say.

That challenges pioneering ideas by local food advocates like Arizona’s Gary Nabhan, who suggests eating food grown within 150 miles of home as a way to support local economies, increase food security and consume fewer resources, especially fossil fuels, when stocking the fridge.

“While the concept of food miles was useful in getting people to think about the issues around carbon emissions and food transport, it’s time for a more sophisticated approach,” Coley says. ”Rather than focus on food miles, it would be more meaningful to look at the carbon emissions behind each food item.”

I think any research is good if it invites people to consider their impacts on the planet. But I would add a plug for alternate transportation: walking or bicycling to your local farm store would be the supreme green approach, would still support local economies, and would require no fossil fuels at all.