Yes cyclists don't consume fossil fuels and it is good for exercise etc but FFS please learn to ride your bike properly before venturing out onto the busy London streets. I have no problem with the pros who cycle day in day out, they know what they are doing. It's when summer comes and all the noobs come out, taking up the whole road, swaying all over the place, one hand on the handle bars the other on their mobile/ipod, thinking they own the road, but are really a hazard to themselves and everyone else.
Same thing for weekend drivers. They are another breed.