[Editor's note: Alisa Smith and J.B. MacKinnon, authors of the 100-Mile Diet: A Year of Local Eating, are blogging their latest local-eating adventures from Easter to Thanksgiving. The Tyee will bring occasional excerpts. For the full blog, go to 100milediet.org.]

An interesting question came up the other day while I was talking with a group of local farmers. I'd already learned about a sort-of local beer(!) and where to track down buckwheat honey (smells like socks!), so it had been a good night. Then one of the farmers started thinking aloud. Suppose you have a truck full of food product X that drives in from 4,000 miles away. Say the truck carries enough product X for 200 households. Then you take away that long-distance truck and tell those households to buy the product from a local farm, just 25 miles away. Now 200 people are driving 25 miles each to get product X. That adds up to 5,000 food miles -- or 1,000 more miles traveled than the food from 4,000 miles away. The farmer's question: Would you still encourage people to buy their product X from a local farm?

Strangely, I found myself saying "yes." I know -- now I've got some splainin' to do.

The idea of "food miles" continues to be a great wake-up call to get people thinking about long-distance food -- it was a big part of what inspired Alisa and me to try a 100-mile diet. But it's important that food miles do not become the start and end of the argument. A lot of powerful interests are deeply invested in the current food system and highly resistant to change, and these automatic critics are looking at food miles as local eating's Achilles heel.

The fact is that even when it comes to energy use and fossil fuel consumption, food miles aren't much of a measure. A better bet is what's called a "life cycle assessment," which attempts to measure the impacts of food production from "cradle to grave." Unfortunately, life cycle assessments are complex, highly specific, and have been performed for only a small number of foods.

What a life cycle assessment may show can be surprising. For example, the emerging critics of local eating -- yes, there are people who have a problem with you and I choosing to buy our food from people in our own communities -- often point to the "tomato study." Research for the Department for Environment, Food and Rural Affairs in the U.K. found that it can be more energy efficient to ship in field tomatoes from Spain than to grow tomatoes in the U.K. Similarly, they found that imported organic wheat can be more eco-friendly than local, conventionally-grown wheat. Then there is New Zealand's Lincoln University study, which shows that shipping New Zealand apples 11,000 miles to the U.K. results in fewer greenhouse gas emissions than producing the apples in the U.K. itself.

Knee-jerk critics use such findings to shrug off the food miles argument and even to dismiss the whole notion of eating locally. Just look at the press release headline the New Zealand government used to parade the Lincoln U study: "Food Miles Research Good News For Exporters."

Well, not so fast.

"The problem with life-cycle assessments," said my friend and systems analyst Ruben Anderson, who has grown a bit of a beard and now looks even wiser, "is that they can only compare systems within the current paradigm."

You see what he means if you give more than a glance at the tomato study. The fine print is this: it compares Spanish tomatoes that travel thousands of miles to U.K. tomatoes that are grown in gas-fired greenhouses from February to November, far beyond the natural tomato growing season.

Each of the more controversial life-cycle studies makes these kinds of comparisons, pitting unsustainable systems against unsustainable systems. To examine the New Zealand study and conclude that the best way forward is to continue shipping 11,000-mile apples is particularly ludicrous. A more rational message is clear: Britain needs to shift toward less energy-intensive forms of agriculture, such as organics.

In any case, certain issues are moving steadily toward consensus -- such as the nature of the problem. As the U.K. studies acknowledge, the global trend toward longer-distance trade and centralization of food distribution has resulted in a "large increase" in food miles. To give one alarming example, air freight is the fastest-growing mode of food transport, and though it still accounts for just 1 per cent of U.K. food miles, it produces 11 per cent of CO2 emissions.

Browse the food-system studies and another trend emerges, this time linked to the possible solutions: if you want to reduce the environmental costs of your food, move toward the local, organic, seasonal, and vegetarian.

This makes sense to me at the level of lived experience. I know -- I know -- that eating locally for a year (and beyond) radically reduced the fossil-fuel use associated with my food. Let's stick with the example of tomatoes. Over the past year, Alisa and I didn't buy a single long-distance or hothouse tomato. We ate green and cherry tomatoes in late spring and early summer, field tomatoes in summer and fall, and through the cold months enjoyed the tomatoes we'd canned.

Food miles do matter. They're a shorthand version of the complex energy cycle of food production. More than that, they're a simple reminder of the disconnection between us and our food.

Which gets me back to that Fraser Valley farmer and his question. Why on earth would I tell him that I'd support an actual increase in food miles to get people out buying food from their local farms?

Because we need to reconnect. Because I don't hold out hope for deep, revolutionary change in the food system unless more people begin to remember what real food tastes like, what foods come with each season, who produces their food and how it is produced, what a Brussels sprout plant looks like, how garlic delivers rain down its stem to its roots, how intelligent a pig can be.

To me, that reconnection has to come first. We are talking, after all, about a new life cycle not only for our food, but for you and me as well. -JBM

* * *

An interesting story from the 100-mile trail:

A twenty-something man moves from Calgary, Alberta, to Iqaluit, the capital of Canada's newest territory, Nunavut. When he arrives, he's relieved to see that he can continue to eat vegetarian food, despite the fact that he's now living just south of the Arctic Circle among Inuit people whose traditional diet is dominated by meat. It's just that all his veggie food comes from thousands and thousands of miles away, and almost all of it by plane. Meanwhile, the far north is one of the areas already hard hit by climate change, with the Inuit observing rapid changes in flora and fauna, some of them subtler but even more alarming than the publicized risk of polar bear extinctions.

The young man asks himself: Is my choice to eat a vegetarian diet an 'environmental' choice in Iqaluit?

He answers the question by telling us about what he's eating these days. "Apparently beluga whale is high in vitamin C," he says thoughtfully. "I'll never be able to look at the belugas in the Vancouver Aquarium in quite the same way." –AS & JBM

Find the entire 100-Mile Diet Tyee series here.