There's an interesting thread in Commuting about Commuting and the Environment
Cycling and the environment
According to the article quoted, "A seven mile commute by bicycle instead of car each day saves almost 9 pounds of hydrocarbons, more than 66 pounds of carbon monoxide, 4.4 pounds of oxides of nitrogen and 1319 pounds of carbon dioxide emissions annually. If just one out of every 10 commuters who now drive to work switched to bicycling, the savings would amount to 2 billion gallons per year and reduce carbon dioxide emissions by 25.4 million tons 8 bicycles can be parked in the space required for just one car"
Is this article correct? That's an awful lot of atmospheric damage. Now I'm quite proud I didn't use the car all week (until this morning, when I drove my bike to the LBS...for repairs.)