Math lessons for locavores

Stephen Budiansky, the author of the blog liberalcurmudgeon.com, writes in the N.Y. Times today that the local food movement now threatens to devolve into another one of those self-indulgent — and self-defeating — do-gooder dogmas.

Arbitrary rules, without any real scientific basis, are repeated as gospel by “locavores,” celebrity chefs and mainstream environmental organizations. Words like “sustainability” and “food-miles” are thrown around without any clear understanding of the larger picture of energy and land use.

The statistics brandished by local-food advocates to support such doctrinaire assertions are always selective, usually misleading and often bogus. This is particularly the case with respect to the energy costs of transporting food. One popular and oft-repeated statistic is that it takes 36 (sometimes it’s 97) calories of fossil fuel energy to bring one calorie of iceberg lettuce from California to the East Coast. That’s an apples and oranges (or maybe apples and rocks) comparison to begin with, because you can’t eat petroleum or burn iceberg lettuce.

It is also an almost complete misrepresentation of reality, as those numbers reflect the entire energy cost of producing lettuce from seed to dinner table, not just transportation. Studies have shown that whether it’s grown in California or Maine, or whether it’s organic or conventional, about 5,000 calories of energy go into one pound of lettuce. Given how efficient trains and tractor-trailers are, shipping a head of lettuce across the country actually adds next to nothing to the total energy bill.

It takes about a tablespoon of diesel fuel to move one pound of freight 3,000 miles by rail; that works out to about 100 calories of energy. If it goes by truck, it’s about 300 calories, still a negligible amount in the overall picture. (For those checking the calculations at home, these are “large calories,” or kilocalories, the units used for food value.) Overall, transportation accounts for about 14 percent of the total energy consumed by the American food system.

The real energy hog, it turns out, is not industrial agriculture at all, but you and me. Home preparation and storage account for 32 percent of all energy use in our food system, the largest component by far.
 

Food miles are fashionable; where’s the safety?

Trying to include considerations of microbial food safety — the things that make people barf — when encountering the dogma of fervent foodies is an occupational hazard. Over the years I’ve been slandered, threatened with lawsuits and harm to my person. Taking on the natural-organic-local cabal — including the Food Network which didn’t like our analysis of food safety errors on cooking shows — can be challenging.

So James E. McWilliams should be prepared for lively correspondence. McWilliams, the author of “A Revolution in Eating: How the Quest for Food Shaped America” and a contributing writer for The Texas Observer, writes in a N.Y. Times op-ed this morning that reducing food miles — how far food has traveled before you buy it — is not necessarily better for the environment.

"There are many good reasons for eating local — freshness, purity, taste, community cohesion and preserving open space — but none of these benefits compares to the much-touted claim that eating local reduces fossil fuel consumption."

"As concerned consumers and environmentalists, we must … be prepared to accept that buying local is not necessarily beneficial for the environment. As much as this claim violates one of our most sacred assumptions, life cycle assessments offer far more valuable measurements to gauge the environmental impact of eating. While there will always be good reasons to encourage the growth of sustainable local food systems, we must also allow them to develop in tandem with what could be their equally sustainable global counterparts. We must accept the fact, in short, that distance is not the enemy of awareness."

Brilliant. But once again, the notion of microbiological safety is absent from the discussion. How about sourcing food from the place that can yield the fewest number of sick people?