[LINK] “The 100-mile myth”

[rfmcdonald]

The idea of the 100-mile diet--the idea that one should only eat food produced within a hundred miles of your residence the better to help the environment--is simple-minded, overlooking the very real benefeits of globalization. Surprise. University of Toronto geography professor Pierre Desrochers has helped popularize this point in Canada.

[F]arming methods make up so much more of a particular food's carbon footprint, it is remarkable that all those food-mile-counters missed it. A 2008 study published in the academic journal, Environmental Science and Technology by a pair of environmental engineers at Carnegie Mellon University found that just 11% of greenhouse gas emissions related to food come from transportation. Final delivery to the retailer accounted for just 4%. On the other hand, 83% of emissions involved in your lunch today are directly attributable to the food's production.

What locavores forget, or don't stop to consider, is that calculating the emissions over the entire life-cycle process is far more complex than counting transportation miles. Local producers, for example, often store their fruits and vegetables using refrigeration for several months to stretch into the off-season. Certain climates also demand more CO2-heavy inputs, such as pesticides and fertilizers. And suboptimal growing conditions often mean clearing and farming more land to gain yields. "If you want to preserve wilderness areas, the way to go is modern, intensive farming and international trade," says Pierre Desrochers, a geography professor at the University of Toronto.

[. . .]

Large-capacity food transportation, he notes, is often extremely fuel-efficient. "A highly efficient container diesel-powered ship can move huge quantities of stuff ... with a tiny, tiny, tiny energy signature." And when producers do export by airfreight, often their carbon footprint is reduced, since often they can slot their deliveries into the excess capacity available in planes that are already headed where they need to go. But in other cases, the oversimplified food miles argument can grossly misjudge the environmental impact: Flowers grown outdoors in Kenya, for instance, weigh very little, and even when delivered by air, they still come out ahead of European-grown blossoms requiring heated greenhouses (13,300 lbs of CO2 per 12,000 cut roses shipped from Kenya to the U.K. vs. 77,000 lbs for Dutch ones). Though greenhouse gas emissions themselves are often not part of the price of food, all the fuel, fertilizer and land clearance responsible for creating them -- all net contributors to greenhouse gas emissions -- are all in there. "In a global market economy, people have the incentive to use resources as efficiently as possible," Prof. Desrochers says. The steeper the price tag on a bag of baby carrots, the more likely their production came at an environmental cost.

[. . .]

When British consumers insist on buying locally grown tomatoes, meanwhile, they're patronizing producers who emit 5,278 lbs of CO2 per ton, produced largely by heated greenhouses, according to a 2005 study by the U.K.'s own Department for Environment, Food and Rural Affairs.

Spanish tomatoes, by comparison, emit barely a quarter of that amount, the study found, even after shipping to London grocers: just 1,389 lbs of CO2 per ton. Several similar analyses have thrown cold water on the pro-environment argument for all kinds of fruits, vegetables and dairy products.

In the meanwhile, in a critical post at treehugger.com the author ignores his points and writes that the food produced by the globalized agriculture that feeds the world “ they taste like wood and are not worth transporting at all” while commenters write things like “I did see corn for $1 per ear at a farmers market this season - I thought it was too expensive and didn't buy any. Are carrots a bit more than at the supermarket? yes. Are they so sweet that it makes you inspired about carrots again? yes.” It’s nice to know that these gourmands are so devoted to their cause of the day, but, really.