Dirk & O2,
Thanks for that outline of fuel use per person for different modes of transportation. The defect of both that method and mine is the effort needed to estimate what’s being left out. What I think people need is a list of impacts something like the one you provided, but that is easyier, inclusive and comparable.
People just want a direct easy way to compare choices, not spend all their time trying to understand unexplained units of measure and wondering what is left out. For example, using the cost of shipping to calculate fuel use might leave out the subsidies for the transit system that go into it, yes, but that’s fairly easy to factor in.
That exact same omission, however, is also made when you add up only the directly accountable fuel uses of the transit system, and that is not possible to adjust for. The direct fuel use information for subsidies doesn’t exist.
I think it’s the “information problem” that is both most interesting and most significant. When you pay for a shipment you know some of the money goes for fuel and some goes to the truck driver and other people providing their necessary parts of the service. People basically provide “information” as their service.
That’s a “physical service” in that it’s physically necessary for someone to steer the truck where should go, and you pay for it by giving the people helping provide the service credits to use for their consumption. You can find the receipts for the truck fuel, and add those to the embodied energy cost of the delivery, but you simply never find out what the truck driver or any of the other people really did with their parts of he fee.
That’s where using the average economic energy cost for their contributions is a godsend. It lets you start from an easy and inclusive measure, as well as catching real embodied energy uses that may be ten times the size of the ones that are easily visible.
It’s an approximation, yes, but we can be fairly sure that money for goods and services goes to every kind of person to support every normal thing people do with it, and fans out as it is passed along to support every part of the whole economy. You can also be fairly sure that all money earned is used for goods and services of some kind, either spent or invested.
Thus calculating environmental burdens as shares of economic earnings has the makings of a superior decision making tool. It’s fairly inclusive, easily calculated, and easily compared.
It also points out the truth that everyone has been in a habit of denying, that increasing everyone’s incomes increases their direct physical impacts. That’s simply because we do all pass our money along to others for them to do whatever they want with it. It’s such a simple and obvious thing, it’s truly amazing so many people treat it as invisible.
More technical backup on my method is available online at www.synapse9.com/design/dollarshadow.htm fyi