On Mon, 14 Jul 2008 10:50:22 +0100, Jon Green wrote:

Look at it another way: the extra fuel burnt from the additional weight
of you and your baggage, since the plane was going to fly that route
anyway, was miniscule. You could probably offset it by growing a couple
of rows of carrots.

A post in sci.aeronautics.airliners from a guy with a boeing.com
email address disagrees:
http://yarchive.net/air/airliners/mpg.html

"It will vary pretty widely depending on the airplane, the engines, the
condition of the engines, the range the airplane is intending to fly, and
the weather (hotter is always worse). All that to say a precise answer is
very difficult and will wobble a great deal. A good tire kicking number
is to figure about half the weight of the passenger and bags. That is,
if a 180 lb passenger+bags is added at the last minute, you can probably
figure that on the average flight on the average airplane somewhere near
90 lb of fuel (more for longer ranges, older aircraft, etc). That is
about 15 gallons."

Of course this might just be the point of view of a Boeing toilet cleaner,
or a teenage lesbian pretending to be a middle-aged aeronautical engineer.

Not a point of view that's popular amongst eco-warriors, because it

....is wrong?

--
One way ticket from Mornington Crescent to Tannhauser Gate please.