Here's what we know: humans are part of the food chain and the carbon cycle, we breathe in oxygen and exhale carbon dioxide. When we exercise, our CO2 output increases.
So when Washington State Representative Ed Orcutt (R-Kalama) said last week in an email that the act of riding a bicycles "results in greater emissions of carbon dioxide from the rider," strictly speaking, he is correct (but also missing the point).
Any exercising athlete creates greater emissions of carbon dioxide than a resting couch potato.
Orcutt's thoughts on bicyclists' polluting power, however, seem to lead him to think that a tax on the sale of bicycles is a natural correlation. As related by Bike Portland by editor Jonathan Maus, a recent transportation tax package proposed by Democrats in the Washington legislature includes the bicycle sales tas.
Orcutt, Maus says, is "staunchly" opposed to taxes of any kind...except, reportedly, the bike sales tax in the legislation. That's because Orcutt erroneously thinks only cars pay for roads, cyclists are polluting, and thus polluting cyclists should pay their way.
Here's some of the text from an email Orcutt sent to a constituent:
"I am not a fan of the House Transportation tax proposal, nor of many tax proposals, but I have to admit I think there are valid reasons to tax bicycles. Think about this for a moment: Currently motorists are paying to use their cars on the roads while they are actually driving their cars. At the same time they are paying for bike lanes because there is no gas tax — or any transportation tax — generated by the act of riding on the roadways. So, if cars pay for the roads they are using, it only makes sense that bicyclists would also be required to 'pay' for the roads they use when they are actually biking on them.
Also, you claim that is is environmentally friendly to ride a bike. But if I am not mistaken a cyclists [sic] has an increased heart rate and respiration. That means the act of riding a bike results in greater emissions of carbon dioxide from the rider. Since CO2 is deemed a greenhouse gas and a pollutant, bicyclists are actually polluting when they ride."
One strange aspect of the argument is that while humans CO2 emissions are generated from our food fuel and many plants use our CO2 for their own growth cycle, cars' CO2 emissions are generated from fossil fuels which were not part of the natural carbon cycle. Fossil fuels add greenhouse gases to the atmosphere, while most human-metabolism produced CO2 is carbon neutral.
In order to understand cyclists' pollution potential, I consulted the Cozy Beehive (CB) blog, written by a mechanical engineer. CB did some rough calculations on the annual CO2 pollution of a bicycle driver compared to a car driver, and came up with the following figures:
A 2009 Toyota Prius would generate approximately 3,800 kilograms of CO2 for 15,000 miles of driving in a year.
A human cyclist would generate approximately 372 kilos of CO2 for the same 15,000 miles of driving at 15 mph.
This doesn't take into account the other pollutants - NOx, hydrocarbons, and carbon monoxide - that come from some cars' exhaust. Nor does it factor in all the breathing that the occupants of the cars are doing during those 15,000 miles. Or what the cyclist ate.
It does signal that the 'bikers don't pay' idea is still stubbornly believed in.
UPDATE: Orcutt apologized at the Seattle Bike Blog for his comments on polluting cyclists.
Via Bike Portland