Here is a little piece of evidence for all those self righteous London bus users....according the Transport for London's environmental report the average CO2 pollution per bus passenger km (103 grams per passenger per km) is not much better than that of cars: 124 grams....so there is no way round it: get out of the bus and on your bike....Don't believe it? Check out table 4 in here...  ¶ 21:32