[DoctorDoom]

GF was travelling recently and the captain came on and announced that her plain was burning 2 gallons of fuel per mile. She was surprised - it didn't sound all that bad since there were 100s of people on the plane. I though I would find out for sure, so I looked it up and found this:

http://www.iata.org/whatwedo/environmen ... ciency.htm

Highlight: 49 mpg per passenger in 1998, new aircraft as high as 80 mpg per passenger. That's a reasonably favourable comparison versus driving, even for a couple, though driving might still beat this for, say, a family of four in one car.

Just for laughs I though I'd compare this to taking the train, and found this:

http://www.chooseclimate.org/climatetrain/ecobal.html

Highlights: trains are in the 100-200 mpg range (per passenger), while aircraft have 3x greenhouse impact per unit of fuel used verus ground transport.

[Wildwell]

Well at least 200 mpg. Even old 1950s diesel locos get 1 mile to a gallon, if it's hauling coaches with 600 people behind, that's 600 mpg. Then you have the ability to electrify and run on Nuclear/hydro, on motors that are 90% efficient compared to 30%...so that’s the equivalent of 1800mpg.. That's not fantasy - they're doing it right now in Switzerland and France. That's without taking into account the 20% energy savings regen braking would bring.

You have to take real loads into account though, and off-peak and rural services bring the overall load down, in the UK case to around 35% and Germany 50%. But then the average load of a car is 1.5. The UK department of transport calculated on average a rider in a car in getting 40mpg and a deisel train rider is getting 180mpg - although in a crowded commuter trains this would be 500mpg.

Taking the Eurostar (trains) from London-Paris is thought to emit 19 times less carbon than flying, on account of realtive effeciency and nuclear generation in France.

Airlines have long used the comparison to cars, but that assumes a full load and Airlines tend to fly several hundred or thousand miles. In fact one airline flight can be the equivalent of a whole years driving. So it's a bunch of spin really.