I don’t think that’s so much? A car burns 1 liter to travel 15 kilometer’ish, and carries 4 people.
An airplane burns 40 liters to travel 15 kilometers too (900 kph), but carries 160 people.
That’s about 40x more than the car, so the fuel economy per passenger is about the same.
Of course jet fuel is probably a bit more polluting, but it’s still interesting how close it is.
The greenhouse effects of flying is about 3-5x the effect of just burning the fuel.
Could you explain why this is?
Water vapor in the stratosphere has a very high radiative forcing. Offset somewhat by particulates in the upper atmosphere.
Cirrus clouds and contrails have a distinct, and large, additional forcing.
What do you mean by this? What else than burning the fuel contributes to the greenhouse effect?
Building the airplanes? Servicing them? Heating the airports?
That's nebulous, are we going to claim that for all industrial processes?