This is a very interesting report. I wonder how the results would compare to Sydney and other cities.
Urban car travel is estimated to cause 367 grams CO2-e of emissions per passenger-
kilometre. Walking, bus or light rail cause about the same emissions as a car with a driver
and a passenger. Motorcycling causes about the same emissions as a car with a driver
and two passengers. Cycling causes about the same emissions as a car with a driver and
Note that the analysis includes exhaled emissions, but does not include extracted emissions from plants used for food. So, I guess that the emissions from a vegan would be virtually nil, minus accounting for other factors like the use of petrochemicals such as fertilisers, herbicides, and pesticides; and transport of food by means that emit greenhouse gases. For a vegetarian, I’d expect that life cycle emissions for human powered transport would be slightly more, due to factors such as construction of buildings to house animals (I think that even free range chooks prefer an barn at night); and a lower efficiency in terms of converting energy from the Sun to chemical energy in the human body. For omnivores, I’d expect that the emissions per human-kilometre would again be higher.
Another perhaps unexpected fact is that intercity air travel is published as the mode of travel with the lowest emissions per passenger-kilometre.
Note however that rail is electrified and so the emissions per passenger kilometre will decrease as the electricity generation mix shifts to renewable energy.
Still, the article results were unexpected. They give good reason from an environmental perspective to invest in a motorcycle and use for long range transport, and use a bike or other human powered transport for shorter distances. It’s also good to offset carbon.