Do you know that global transport emissions comprised about 23% of direct CO2 emissions in 2008, with land transport accounting for the largest share (16.5 %) under "business as usual" scenarios emissions are projects to rise rapidly in absolute terms. And that Diesel particles contain black carbon, a short-live climate change pollutant? It is up to each of us to make a change, as shift from private motorised transport to prioritized cycling, walking or public transport include reduced respiratory/cardiovascular diseases from air pollution, less traffic injury and noise stress. In addition, large benefits are expected from increased physical activity which can prevent some cancers, type 2 diabetes, health diseases and other obesity related risks. Consider that urban air pollution (much from transport) and traffic injuries kill some 2.6 million people annually around the globe and active transport can help prevent many of the 3.2 million deaths from physical inactivity (http://www.who.int/hia/green_economy/transport_sector_health_co-ben...).
Just to think about it ... in the morning, if you look in the streets of your city, how many cars do you see and how many cyclists or people walking ?