I also cannot completly calculate and compare the subsidisation of each transport system. But when I recognise that the tickets for a lot of flights are much cheaper than the train tickets to the airport - I doubt that this is only due to the unbeatable efficiency of air transportation. OK - there are certainly many more reasons for that, but the zero fuel taxation is certainly one major point that can hardly be justified.
Jonty - so the Kyoto Protocol is ratified by 162 countries just to face a natural random phenomenon?