Of course a lot of people do care--but do you really think telling people how green it is is the best way to get them to stop driving to work? I don't. I can't think of anybody I know who'd respond to that. As far as I can tell, people don't, for the most part, make major, sustained lifestyle changes for reasons as vague as "it's good for the environment." Selling that part of the bicycle thing isn't likely to make much impact.

Gas prices... that hits a little closer to home, but as soon as the prices go down again (assuming they do), that's the end of it.

Bicycling is fun. Everybody already knows that. But no, we can't possibly push that aspect of it. We have to feel politically superior, which translates into taking potshots.

Great angle. That'll get 'em buying Bike Fridays in droves.

The way I get people to consider commuting by bike is to tell them how much fun it is, and how much cheerier I am when I get to do it. They generally fill in the rest of the conversation with their own concerns, which are usually in this order: 1) Fitness. 2) Cost savings.

Where does "green" fall on that list? It doesn't. Nobody cares who didn't care already.

I'm all for environmental responsibility, but anyone who thinks the key to accomplishing it is to hammer on the environmental benefits of a hugely inconvenient lifestyle change doesn't, in my opinion, see human nature very clearly.