This study attempts to find a hypothetical case where a person who bikes to work has a higher carbon footprint than a person who drives to work. I’m drastically oversimplifying, I’m sure, but what I gather is that if a vegetarian with a very fuel efficient car lived the same distance from work as a person who eats a huge amount of meat but bikes to work, the person who bikes to work could have a slightly higher carbon footprint. It is surprising, but I don’t think the right way to spin it is to say biking is bad. For one thing, people who bike to work are going to live much, much closer to work on average than people who drive to work. I also bet people who drive a lot eat more meat, on average, than people who don’t. Because steak and SUVs just go together. But I think the right take home message is that driving and meat are both pretty bad, environmentally speaking. If you want to help the environment, these are probably the two things you can limit or give up that will do the most good.