About a year ago (August 2007) the Times Online posted an article entitled “Walking to the shops ‘damages planet more than going by car’” which made the claim that more greenhouse gas’ are produced by someone walking to the shops (and the extra food they need to eat) than by someone who drives there. After having a discussion with a housemate who thought I had made the whole claim up I dug out the article and sent it to him, I also thought I might as well blog about it.

The main claim in the article is the following:

“The sums were done by Chris Goodall, campaigning author of How to Live a Low-Carbon Life, based on the greenhouse gases created by intensive beef production. “Driving a typical UK car for 3 miles [4.8km] adds about 0.9 kg [2lb] of CO2 to the atmosphere,” he said, a calculation based on the Government’s official fuel emission figures. “If you walked instead, it would use about 180 calories. You’d need about 100g of beef to replace those calories, resulting in 3.6kg of emissions, or four times as much as driving”"

And also:

“What if, instead of beef, the walker drank a glass of milk? The average person would need to drink 420ml – three quarters of a pint – to recover the calories used in the walk. Modern dairy farming emits the equivalent of 1.2kg of CO2 to produce the milk, still more pollution than the car journey.”

While looking for the article again I also found a counterview/follow up to it entitled “Walking vs. Driving: Which is the Better Choice?“ which alters the calculations done based on a different diet and concludes that walking is better:

“The study works with a given distance, 1.5 miles, with all caloric expenditures for an 189-pound, 35-year-old male, and car based calculations for a 2,853 pound Nissan Sentra. They then examine the emissions using the varying dietary trends. They certainly agree with Goodall’s assertion that high meat content diets are higher in carbon emissions. However, when exploring the typical American diet where beef and pork contribute about 10% of total daily caloric intake and dairy products about 7%, (statistics they determine using existing studies), they find that walking is the better choice by a factor of four”

So its not particularly clear whether or not the claim is true and to make a conclusive statement would need alot more reesearch and analysis into the many other factors involved with the production of the vehicle, storage of the food etc. But it does make you reconsider exactly what is good for the environemt.