The document discusses estimates of carbon dioxide emissions saved from bicycle use based on a "Be-Cycle" game created by the Cycle Cities project. It estimates that if all bicycle trips replaced car trips, 24 million tonnes of CO2e could be saved, but in reality some trips would replace bus or walking trips instead. Accounting for those alternatives, bicycle trips could still save 11 million tonnes of CO2e. This amount represents a 3-6% reduction towards the EU-15's commitment under the Kyoto Protocol to lower greenhouse gas emissions by 8% on average.