🚀 go-pugleaf

In article <SLAGLE.92Jun8203710@sgi417.msd.lmsc.lockheed.com> slagle@lmsc.lockheed.com writes:
> [stuff deleted]
>As for your claim of environmental rectitude, your point raises
>an interesting question, one about which I freely admit
>considerable ignorance.  As difficult as it is, we can probably
>come up with some sort of reasonable, quantitative estimate of
>the environmental cost of using an automobile.  But if we want to
>replace the use of a car with some person-powered vehicle, then
>we need to start thinking about the environmental costs of
>generating a given level of human power output.  Given that
>people are notoriously inefficient converters of energy (anybody
>have any numbers?), it seems possible that the net environmental
>damage difference might well tip in favor of cars.  It seems
>counter-intuitive, I suppose, and cars do their damage in a
>particularly bad location.  Still, the growing, processing,
>transporting, and selling of food products and the subsequent
>disposal of the fecal and unusable remainder present very
>significant environmental costs in addition to their well known
>monetary costs.
>
>So the question that I have is the following:
>
>Can anybody come up with any kind of realistic estimate of the
>comparable environmental and economic damage that would result
>from a substitution of human for automotive power on the margin?
>Can we really say that using a car to get to and from work is
>really worse for the environment, all inputs and outputs
>considered, than is riding a bicycle?

Mark, you ask interesting questions.

But we can at least begin with the fact that if I drive to work I need to
accellerate and decelerate several thousand pounds of metal while if I
go by bike I'm only dealing with my own weight plus 25 lbs.  This difference
dwarfs the human body's being a "notoriously inefficient converter[] of 
energy", and is responsible for estimates that a bicyclist, if he could
run on gas, would get upwards of 1500 miles per gallon.

Cars aren't all that efficient either, BTW.  I have at home a chart showing
what happens to the potential energy in a gallon of crude oil between the
time it leaves the ground and the time it is converted into useful motion
of a car.  Something like 20% is lost to refiniement into gas; by the time
distribution, mechanical and combustion inefficiencies, aerodynamic drag
and tire/road friction etc. are accounted for only 5% of the original
energy gets any useful work done.

On a different tack, Les Earnest maintains on rec.bicycles that sustained
bicycle touring costs as much per mile (in food) as does driving.  He's
eating in restaurants (which I don't do but which does approximate the
convenience of gas stations), but even so this is an indication that there
would in fact be changes to levels of food consumption if bicycling really
caught on.

[I may be wrong about Earnest's claim: I don't remember if he equates cars
and bikes on a per-mile or per-day basis.]
-- 
****************************************************************************
Eric House			"My employer doesn't share its opinions with
			   	 me, so I can share only mine with you"