Don't forget the energy needs of the people that make the cars. My favorite point, however, is that for my car, 100% of the energy used is for purposes of prop

Don't forget the energy needs of the people that make the cars. My favorite point, however, is that for my car, 100% of the energy used is for purposes of propelling the car from point at to point B. For a human, the energy from walking is a fraction of the total energy use for the day, so if I want to take into account the cost of the food supply chain devoted ONLY to my walking to work.