Reasonable Rules for Eating Locally

September 26, 2007

A local friend of mine recently tried out the Consumer Consequences game from American Public Media. (Shirley Siluk Gregory offered a review of the game here last week, as well.) It is essentially another version of a set of questions that help model the now familiar question, "How many Earths would we need so that everyone could live the way you do?" My friend was a bit shocked to find that her lifestyle would require almost 3 Earths.

When she wrote about this in her own blog, she wrote, in part, "The eye-opening part is that our biggest contributor to non-sustainability is our family’s food habits. More reason to work on 1) eating more fruits and vegetables, and 2) eating locally." That triggered a discussion about local food and food miles, and this is an expansion on my thoughts in that discussion.

There are many variables in food production and transportation, so there may be some foods that ship effectively. But when Michael Pollan, in The Omnivore’s Dilemma, points out that there are 10 calories of energy going into the production and transportation of every calorie of food we eat, it’s clear that the system is pretty inefficient. (There, too, it’s an average figure.)

There was an article in TreeHugger several months ago that was looking at whether it was better to get your bottled water shipped from the South Pacific or trucked from France (to the UK… it was a UK article). In terms of fuel consumed per pound of material delivered, the more local option was less efficient, because sea freight is an efficient method of transportation. (The absurdity of bottled water is its own issue, but that was the example the article was using.)

But when you are eating California produce in Michigan, you aren’t getting that brought here by ship; it’s being trucked. Even McDonalds’ beef from South American ranches may be shipped to American shores, but if you’re eating it in Michigan, it rode several hundred miles, in addition to those thousands of sea miles, to get to you.

There may be some cases where long distance efficiencies make a certain amount of sense. But by and large, eating locally is the more appropriate choice. And even if you have to pay a bit more for the local option, or if it takes a little more energy at present, it’s still a productive thing to help support the local market so that it can develop and get to the point of being the more sustainable choice all around.

An article in The Economist that was brought into the discussion pointed out that (in London, again) it was more efficient to truck in tomatoes from Spain in the winter than it was to grow them locally in heated greenhouses. Greenhouse grown food shouldn’t necessarily qualify as local food just because it wasn’t shipped thousands of miles. The issue is less the actual distance the food has traveled than it is the energy that transportation and production are requiring. Miles are an easy way to categorize it, but it’s energy, not actual miles traveled that is the real issue. It’s obvious that, if you are attempting to adopt a broadly sustainable approach to food production, then dumping huge amounts of energy into greenhouses to grow an out-of-season food is no better than shipping.

The Economist article also notes,

The term "food mile" is itself misleading, as a report published by DEFRA, Britain’s environment and farming ministry, pointed out last year. A mile travelled by a large truck full of groceries is not the same as a mile travelled by a sport-utility vehicle carrying a bag of salad. Instead, says Paul Watkiss, one of the authors of the DEFRA report, it is more helpful to think about food-vehicle miles (ie, the number of miles travelled by vehicles carrying food) and food-tonne miles (which take the tonnage being carried into account).

Some of this is weak reasoning. If the same shopper is going to the store in their SUV to buy a bag of lettuce, their contribution in the transportation scheme is equally abysmal whether they choose to buy trucked produce from thousands of miles away or a locally-grown option instead. Neither the local farmer nor the far-distant producer is making individual deliveries to stores. And even if the long-haul semi is carrying 10 times as much as the local farm truck per gallon of fuel, if the food has to go 150 miles instead of 2000, that transport efficiency doesn’t pay off.

Personally, I don’t need to eat corn-on-the-cob in January. Let that truck stay in Florida. I’ll wait for the local stuff when it’s in season, in the summertime. Shipped food also needs to be robust enough that it can withstand the rigors of transportation and distribution. Local food can often be more flavorful and enjoyable. You can find thin skinned tomatoes and tender fruit that would never stand up to shipping at a local farm stand.

Food miles may be a poor measure, but it’s probably better shorthand for food energy consumption than anything else without getting into ridiculous levels of complexity. But "local food" needs to be tempered with reasonableness. Another friend, and self-proclaimed foodie, is fond of Chinese cooking and disdains the concept of local food because he couldn’t get the ingredients for the dishes he loves from a local provider.

But eating locally does not mean only eating what is produced locally. Certainly it can be an informative exercise. Trying out the 100-Mile Diet for a month can certainly be an eye-opening experience. But, as Michael Pollan points out, only the deeply dedicated eat exclusively and continuously from their local foodshed (a term for local food production areas). Trade between foodsheds is natural and normal. It certainly isn’t only a recent innovation. Food was the focus of some of the earliest commerce in history.

A good analogy for eating locally may be found in the LEED guidelines. A building does not need to use 100% local materials to qualify for Regional Materials Use credit. If 10% of the materials used in a building come from within 500 miles of the site, that earns the project a point (and 20% Regional Materials garners an additional point). Food is much more localized than building materials, but finding and following a reasonable target for how much local food you want to eat is a much better way of accomplishing eating locally than worrying about every last mile everything took to reach your plate. This number may vary from location to location, as well as by season. In the wintertime, most northerners will eat less locally produced food than they do in the summertime. Personally, I’m going to start tracking it and see if I can reasonably eat 25% of my food from local sources.

Image Source: Michigan Dept. of Agriculture