At last week’s 2009 Poptech conference, author Michael Pollan made this claim: “A vegan in a Hummer has a lighter carbon footprint than a beef eater in a Prius.”

Michael Pollan

Michael Pollan

Days later, Pollan, author of the bestseller Omnivore’s Dilemma, retracted the statement after researchers showed that Hummers are significantly more destructive to the environment than hamburgers.

In a blog posted by Reuters’ Adam Pacisk, this evidence came to light:

  • Gidon Eshel and Pamela Martin of the University of Chicago found, in a 2006 study, that the difference between a heavy meat-eating diet and a vegan diet was about 2 tons of carbon dioxide equivalent per person per year.
  • The professors found the difference between a Prius and a Hummer-sized SUV is 4.76 tons per year.

Therefore, switching to a Prius from a Hummer saves more than twice as much greenhouse gas emissions as giving up meat. Of course, going vegan and hybrid at the same time would be like super-sizing your carbon offsets.

Pollan Eats His Words

After Pacisk posted his blog with the facts, Pollan wrote the following note to Reuters:

“After digging into it further, and consulting Gidon Eschel, I don’t feel comfortable defending [my earlier statement]. 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.”

Al Gore with Burger

Al Gore’s inconvenient dietary habits

Pollan’s acknowledgment that he put his foot in his mouth is not likely to stop the ongoing debate about the relative impact of clean driving and dirty dining. The blogger Fat Knowledge posted a 2007 spreadsheet calling a tie between Hummer-driving vegans and burger-chomping Prius owners. Then, there’s the infamous 2006 CNW study that claims that Priuses are worse than Hummers in terms of energy consumption, regardless of drivers’ diets. And let’s not forget Big Vegan’s 2007 challenge to Al Gore to give up his cherished cheeseburgers to prove his commitment to reducing global warming.

In issuing the challenge to Gore, various vegetarian organizations and People for the Ethical Treatment of Animals cited a United Nations study showing that raising animals for food generates more greenhouse gases than all the cars and trucks in the world combined.