[londons_explore]

On many routes, even a small gas tax would just make airlines fill up their tanks at the other end of the journey and carry extra fuel in one direction.

Carrying extra weight is bad and causes more CO2.

[wolverine876]

That's a bit hard to believe; it would seem to depend on the tax. Do you have any basis for it?

[Gravityloss]

Is that true? Airplanes need so much fuel, I think they're always tanked at each destination.