In case you have not read or heard about the New York Times article about the paper by Karl Ulrich and the rebuttal by Andrew Leonard; Leonard summaries Ulrich position as "Cyclists live longer, thus consuming more energy, bad for environment. Result: Bikers lose all will to live." And Paul Higgins position as "Cyclists aren’t fat, thus lower healthcare costs, providing money for carbon abatement. Result: Bikers save the world."
Links to articles and papers follow:
New York Times Article:
https://www.nytimes.com/2006/07/22/business/22online.html?_r=3&oref=slogin&oref=slogin&oref=slogin
The Paper by Karl Ulrich:
https://opim.wharton.upenn.edu/~ulrich/documents/ulrich-cycling-enviro-jul06.pdf
Rebuttal by Andrew Leonard:
https://www.salon.com/tech/htww/2006/07/18/bikers/index.html
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Biking in Baltimore