Bicycling Climate Change Threat

The supposed dangers of manmade global warming from excess carbon dioxide (CO2) generation is often used as an argument for junking new road construction projects and otherwise discouraging car use. But in Europe someone has actually done the calculations!

Bicycles: 4 adults cycle 5 miles to work at an average speed of 8mph, time taken 38 mins (0.63hr).Exercise breathing rate: 6 cub metres/hour, so cyclists exhale 4 x 6 x 0.63 = 15.1 cub metres air. Exhaled air contains 4% carbon dioxide (CO2), 1 cubic metre exhaled air contains 73.3g CO2. So the amount of CO2 exhaled by the four cyclists is 15.1 x 73.3 = 1108 g.

Car: Four adults travel by car, travelling 5 miles at average 22mph, time taken14 mins (0.23hour). At-rest adult breathing rate is 0.4 cub metres/ hour. So four adults in car exhale 4 x 0.4 x 0.23 cubic metres air = 0.37 cub metres air. 0.37 cubic metres exhaled air, 4% CO2, contains 0.37 x 73.3 = 27g CO2. The car exhaust emits 215g CO2 per mile (modern, high mpg), so CO2 emitted is 5 x 215 =1075g .Total CO2 emitted by car and 4 seated adults is 1075 + 27 = 1102g. (from Bernard Abrams abrams@rmplc.co.uk)

No difference! Those sweaty people on bicycles emit as much CO2 into the air as a car.

Now we’ve always believed the best mode is neither the car, the bus, the train nor the bicycle but the walk, indeed the slow amble. The message of true environmentalists will be “Save the Planet, Amble Slowly”.