writes "In a report by the European Cycling Federation, they show Bicycle CO2 emissions to be around 16g CO2/Km. The report however fails to recognise that in some countries, Bicycles cause traffic slow down. For example in hilly, Sydney, Australia cyclists can be found slowing traffic during peak traffic hours by consuming a whole traffic lane to themselves. Drivers will often experience a delay of at least 1 minute trying to navigate past the cyclist into another lane.
If the average passenger vehicle produces around 6g CO2/minute when just idling — if 100 cars are delayed 1 minute by the cyclist, the additional, indirect CO2 production adds 600g of CO2 to their 16g CO2/KM.
In some countries, cycling may be causing excessive CO2 emissions rather than reducing them."