[WalterBright]

Mass transit isn't taxed, it's heavily subsidized by taxes.

[bluepanda928752]

Also, the parent is probably talking about EU intent to apply carbon tax to mass market airlines but exempt the private jets

[WalterBright]

The tax should be simply applied to the carbon content of the fuel.

Use the revenue to subsidize green projects.

[bluepanda928752]

Often but not always; Hong Kong is one of the exceptions I think (at least the MTR)