If you walk 1.5 miles, Mr. Goodall calculates, and replace those calories by drinking about a cup of milk, the greenhouse emissions connected with that milk (like methane from the dairy farm and carbon dioxide from the delivery truck) are just about equal to the emissions from a typical car making the same trip. And if there were two of you making the trip, then the car would definitely be the more planet-friendly way to go.
Mr. Goodall is a member of the Green Party in Britain and a devout environmentalist — he says he has ceased air travel because of its emissions. But he also questions how much good is being done by eliminating short trips by car.
Elizabeth didn't believe me when I mentioned this a few months ago, so I'm finally getting around to posting the details and my sources: TierneyLab via Freakonomics, almost a year ago. I'm also wondering whether Mr. Goodall actually underestimates the amount of CO2 emmitted by humans: he only takes emmissions during food production and transportation into account. But we are not that dissimilar to a car: we burn fuel (food) and emit C02 as we breathe - the more active we are, the more burning of calories, and the more CO2 we emit via breathing. And legs - unlike wheels - are not built for maximum fuel efficiency when moving from A to B.
Beth doesn't have a car, but she's going one better by cycling lots and never consuming any animal products. You can listen to her beautiful music, and you can see a video of a live performance at the legendary Jazz Cafe in London. She also blogs and tweets.