Chris Goodall, author of "How to Live a Low-Carbon Life," sure knows how to drum up the book publicity. His calculation that walking to the grocery store generates more greenhouse gases than driving is rocketing around the blogosphere, kicked into overdrive by an Aug. 4 London Times story sporting the delightfully inflammatory headline "Walking to the shops 'damages planet more than going by car.'"
Goodall's explanation is that the exercise required to walk burns calories that need to be replaced with additional food. If those calories come in the form of beef, he argues, more greenhouse gases are emitted during the process of creating that beef that would have been generated by the car drive.
But as he concludes in an article exploring the conundrum on his Web site:
Of course this doesn't mean we should always choose to use air or car travel instead of walking. It means we need urgently to work out how to reduce the greenhouse gas intensity of our foodstuffs.
Before I found his own explanation, I was prepared to give Goodall credit for being purposefully misunderstood by news outlets willing to trumpet the "better to drive" sound bite while ignoring his real message. But when I visited his Web site, what was the first thing I saw?
Better to drive than to walk
Let's put aside the increasingly popular parlor game in which we drive ourselves insane by attempting to calculate, down to the last calorie, gram of carbon dioxide, and milliliter of crude oil, exactly what consumer lifestyle serves the health of the planet best. Let's consider Goodall's strategy purely on the question of tactics. Let's suppose that Goodall is aiming for more than merely raising the profile of his book. Suppose he actually wants to make the world a better place. What's the global public relations takeaway from how he's framing his message?
Here's how the Wall Street Journal's energy blog reported the news, under the headline "Couch Potatoes Against Carbon":
Walking does more than driving to cause global warming, a leading environmentalist has calculated. Food production is now so energy-intensive that more carbon is emitted providing a person with enough calories to walk to the shops than a car would emit over the same distance. The climate could benefit if people avoided exercise, ate less and became couch potatoes, the Times of London reports.
This is how Tyler Cowen at Marginal Revolution put it, with the headline "What is carbon-friendly?":
Can this result be true? The guy claims that food production and refrigeration is so energy-expensive that it is more carbon-friendly to drive your car than to walk.
Cowen links to Ezra Klein's discussion (headlined "Well now I don't know what to do.") Klein also leads off with "Walking to the store might be worse for the planet than driving?" However, Klein makes a special effort to highlight the real story:
More seriously, the point of the article is how awful our food-production system in the west really is: food is so energy-intense (read: petroleum-intense) that you're better off putting the gas straight into your gas tank for basic mobility.
In each case, we do hear two points: driving is more carbon-friendly than walking, and food-production is energy intense. So if you're paying close attention, you may start thinking more along the lines of a slow food lifestyle, where your diet reflects your duty to Gaia in addition to your own health choices. But as this meme zooms around the world, which sound bite do you think will grab more headlines: "Driving is healthy for children and other living things," or "Watch what you eat?"