Michael Pollan's Prius-Hummer Blunder

What a soundbite it was, for all of two days: Michael Pollan, sustainable food guru and author of "The Omnivore's Dilemma," told the crowd at the 2009 Poptech conference, "Our meat eating is one of the most important contributors we make to climate change. A vegan in a Hummer has a lighter carbon footprint than a beef eater in a Prius.”

That line was blogged and tweeted countless times over the next few days. The only problem? It isn't true.

Reuters' Adam Pacisk refuted the claim shortly after, and here's his math:

Gidon Eshel and Pamela Martin of the University of Chicago published a 2005 paper in the journal Earth Interactions that looked at the relative carbon footprints of plant-based and red-meat diets. They found that the difference between an heavy meat-eating diet and a vegan diet was about 2 tons of carbon dioxide equivalent per person per year. The difference between a Prius and an SUV (they used a Suburban, which gets about the same mileage as a Hummer) was 4.76 tons per year. Pollan’s claim, said Eshel, “is emphatically wrong. If you’re looking at the mean American driving habits and eating habits, it’s not even close.”

For environmentalists, as well as writers and reporters, the Hummer is the standard metaphor. How many times have you heard that a product is "the Hummer of [fill in the blank]?" Or that an action is equivalent to the footprint of a certain number of Hummers? It is a catchy and convenient way to quantify actions and values, but when it's used improperly, it can certainly backfire. Eshel seemed to regret having to debunk Pollan's statement, saying that he was on his side in his heart, but that he did not like to play fast and loose with numbers.  Pollan has since retracted his statement, telling Reuters:

“After digging in to it further, and consulting Gidon Eschel, I don’t feel comfortable defending it. It’s much more important to keep the focus on the central thrust of the environmental case against eating industrial meat, which is not in dispute and certainly does not stand or fall on the case of the vegan Hummer driver.”

“Thanks for your doggedness on this matter, which we can hope will stop this meme before it hurts somebody,” he added.

As for those Hummer drivers, for whom the chances that any are vegans is slim to none—there's a reason they've chosen this vehicle, and it generally has nothing to do with off-roading. According to a small study done by the Journal of Consumer Research, Hummer drivers chose their cars precisely because, through the metaphors of Pollan and other green writers and thinkers, the brand has become a symbol of something much more: Our American right to excess. Said the authors of the study, "For Hummer owners it is possible to claim the moral high ground... The moralistic critique of their consumption choices readily inspired Hummer owners to adopt the role of the moral protagonist who defends American national ideals."