Wednesday, November 26, 2008

Food Miles, Schmood Miles

There are a lot of reasons to eat locally; preventing global warming just isn't one of them. The "Food Miles" concept of reducing greenhouse gas emissions by avoiding produce shipped long distances is a classic example of feel-good environmentalism lacking empirical rigor. As Reason Magazine explains, it makes the most environmental sense to grow food in exactly the same places where it makes the most economic sense. Any given crop has preferences in soil and climate, livestock have preferences in climate and feed, so land and agrochemical use are minimized by growing crops and raising animals in the places most suited to their growth. Then there's the basic logistical issue:
It transpires that half the food-vehicle miles associated with British food are travelled by cars driving to and from the shops. Each trip is short, but there are millions of them every day. Another surprising finding was that a shift towards a local food system, and away from a supermarket-based food system, with its central distribution depots, lean supply chains and big, full trucks, might actually increase the number of food-vehicle miles being travelled locally, because things would move around in a larger number of smaller, less efficiently packed vehicles.
This study was in compact, crowded Britain. The situation can only be worse in spacious America. This excerpt uses the phrase food-vehicle miles. Maybe we can come up with a better term than that, but it hinges on thinking not about total miles traveled, but on miles traveled per item of produce in a given shipment. Think of it this way: you buy a local tomato at the trendy farmers' market instead of one that's been shipped from California, thus reducing "food miles". What you fail to account for is "food-vehicle miles": the local tomato might have ridden thirty miles in the back of a pickup with maybe 50 other tomatoes. The California tomato was shipped cross-country, true, but in a semi-load of millions. The amount of fuel burned per tomato to get it from the field to your house ends up being far less for the mass-market tomato, particularly if you drive further to the farmers' market than the grocery store.

This is all such a great example of the sort of environmentalism that cares more about labels and trends than about actually accomplishing anything. Some of the political motivations are suspect as well; much of the local-food movement has an ugly strain of protectionism to it. Indeed, Kenya has been forced to defend her cut-flower industry from the "food miles" concept, with an ad campaign point out that Kenyan flowers are "Grown Under The Sun" instead of in heated greenhouses and are thus "greener" than British or Dutch cut-flowers. Again, we're back to growing things where they grow best. Crazy talk, I know.

All this is most certainly not to suggest that I'm against buying locally. I think there's a great food security argument to a more distributed agricultural production. There may be some nutritional benefits (though studies are inconclusive). For me, there is without a doubt a mental health benefit; it just feels right to be eating food grown in the community. It supports a more localized economy, a sense of civil interdependence, and a healthier, more traditional lifestyle. So in the end I'm all for local produce, or best of all, food you grow yourself. Just don't try to convince me I'm saving the world by buying it.

1 comment:

Elephantschild said...

The story of Kenya having to defend their ability to grow flowers year round.. it's bad when real life out-satires what would be good satire.