When the complete life cycle of the following modes are taken into account, the carbon emissions are approximately: Bicycle, 21 g CO2/passenger/km traveled Electric-assist bicycle, 22 g CO2/passenger/km traveled Passenger car, 271 g CO2/passenger/km traveled Bus, 101 CO2/passenger/km traveled. European Cyclists' Federation, 2011 - Cycle more often 2 cool down the planet: Quantifying CO2 savings of cycling
A NASA analysis found that motor vehicles are the greatest contributor to atmospheric warming because they release pollutants and greenhouse gases that promote warming, while emitting few aerosols that counteract it. NASA, 2010 - Road Transportation Emerges as Key Driver of Warming
Increasing the mode share of all trips made by bicycling and walking from 12% to 15% could lead to fuel savings of 3.8 billion gallons a year and reduce greenhouse gas emissions by 33 million tons per year. This is equivalent to replacing 19 million conventional cars with hybrids. Rails-to-Trails Conservancy, 2008 - Active Transportation for America
If 20% of Madison, Wisconsin commuters biked to work, it would save 16,687 tons of carbon dioxide emissions, a value of $366,577. If 20% of Milwaukee commuters biked to work, it would save 40,718 tons of carbon dioxide emissions, a value of $821,282. Grabow, M., et al., 2010 - Valuing Bicycling's Economic and Health Impacts in Wisconsin, January 2010
A reduction in carbon dioxide emissions through an increase in biking and walking for transportation has greater health benefits for a population than from the increased use of lower-emission motor vehicles. An increase in active transportation is estimated to reduce 500 fatalities per million inhabitants in cities such as Delhi and London. Woodcock, J., et al., 2009 - Public health benefits of strategies to reduce greenhouse-gas emissions: urban land transport, Lancet, 374, 1930-43
Bicycle traffic in Copenhagen prevents 90,000 tons of CO2 from being emitted annually. City of Copenhagen, 2010 - Bicycle Account, 2010
Bicyclists in Philadelphia ride 260,000 miles daily, saving 47,450 tons of CO2 from being emitted by cars each year. Bicycle Coalition of Greater Philadelphia, 2008 - Double Dutch: Bicycling Jumps in Philadelphia
If 5% of New Yorkers commuting by private car or taxi switched to biking to work, they could save 150 million pounds of CO2 emissions per year, equivalent to the amount reduced by planting a forest 1.3 times the size of Manhattan. Transportation Alternatives, 2008 - Rolling Carbon: Greenhouse Gas Emissions from Commuting in New York City
Half of U.S. schoolchildren are dropped off at school in the family car. If 20% of those living within two miles of school were to bike or walk instead, it would save 4.3 million miles of driving per day. Over a year, that saved driving would prevent 356,000 tons of CO2 and 21,500 tons of other pollutants from being emitted. Pedroso, M., 2008 - Safe Routes to School: Steps to a Greener Future