CO2 Emissions Graph



  1. #1 John S. Wilkins
    July 26, 2008

    I ride a motorcycle. What’s the cost of that in CO2 units? [And yes I do it to be green; also I’m poor…]

  2. #2 Stephanie Z
    July 26, 2008

    John, what’s your mileage like? You should be pretty close to the Prius driver unless you’re very gung ho about acceleration.

    I’m a little torn between being tickled at my low usage and thinking it’s a pity that walking to work doesn’t take just a little more energy. It does feel silly sometimes to get up and exercise before walking in.

  3. #3 ed
    July 27, 2008


    1. I expect a Prius is much more efficient than a “car” in the city, but pretty much like any other small-ish “car” on the highway.

    2. The “load factors” given for buses and trains seem unreasonably high. For example, if you’re talking about subway trains, in my experience the cars are only anywhere near full at rush hour, and even then only near the center of the city. As the train goes out into the suburbs it empties out. And of course it is often not crowded during off-peak hours. I’d guesstimate that the average load capacity per mile on these trains over the entire week is less than 1/4 the number of seats available.

  4. #4 Zed
    July 27, 2008

    A motorcycle will not have the same emission controls as a car so it will not be as good with particle emmisions. CO2 will probably be equivalent to car of the same MPG. I would like to see some real data if it can be found. I ride a Vulcan 2000 with catalytic converters.

  5. #5 Greg Laden
    July 27, 2008

    ed: A prius gets about 50 mpg on the highway.

  6. #6 DCBob
    July 27, 2008

    Actually, if your biking is hamburger-powered, your CO2 emissions per passenger-mile are remarkably high. As I understand the numbers, moderate biking for a medium-sized 165 lb.-man burns about 50 kilocalories a mile, and grain-fed beef yields about 14 grams of CO2-equivalent per kilocalorie of consumable meat – about 4 from fossil fuels and 10 in CO2-equivalent methane from rumination. (Google “CO2 Emissions of Foods and Diets” for the beef values.) So that works out to 700 grams (or about 1.5 lbs.) of CO2-equivalent per passenger-mile, roughly the same as driving an SUV. Shouldn’t stop you from biking, but it seems like a good argument for bagging beef. Chicken yields about one-tenth as much CO2-equivalent and veggies yield about on-hundredth as much.

  7. #7 Umlud
    July 27, 2008

    I thought that a motorcycle would be lower than the carpool number, just by doing a really rough calculation of:

    Estimate of car curb weight (2005 Civic): ~2500 lbs
    Estimate of motorcycle wet wt (2007 Yamaha Virago): ~450 lbs

    Therefore the estimated weight/person of a three-person carpool is 830 lbs/person, slightly less than double the weight of the motorcycle.

    I know that this is REALLY rough, and is based only on the weight. Still…

  8. #8 Marc
    January 19, 2009

    In you can reduce your CO2 emisions.