Now don't shoot the messenger, but I did read somewhere that cycling was actually bad for the environment, as it does you such good that you survive so much longer that you go on to consume much more resources in your life than a non-cyclist that you actually negate the good you do.
Like I said, don;t shoot the messanger. I just read it somewhere, and am just passing it on, and indeed would advise everyone to cycle and recycle and all the other things that are god for the planet.