The idea of this thesis being that if more people ride increased longevity of life may increase popupulation and therefore general power consumption. Assuming that new forms of power are just as dirty as cars this would negate the overal environmental impact of more people riding bikes. :)
THE ENVIRONMENTAL PARADOX OF BICYCLING (PDF)
In the authors own words.
accounting for the latent energy content of the food required for human power.
· A substantial increase in the use of human-powered transportation would engage a substantial
number of currently sedentary people in physical activity.
· Physical activity by previously sedentary individuals increases their longevity, and therefore
their overall energy consumption.
· Depending on the characteristics of the population that adopts human-powered transportation,
there may be little net environmental benefit associated with an increase in human-powered
Discussion on Metafilter.com: If bikes are bad for the environment, what happens if we put a two stroke motor on them? MetaFilter