madrich
It is the reson behind it but apart from as you rightly say provide more money to the govt the whole purpose behind it was to curb flying due to the environmental issues, which it is doing, however you still need to get from A to B so you select another mode of transport so its probably increasing the amount of emissions. not decreasing them, the govt should be encouraging people to fly domestically as it is the most efficient and environmentally way for the masses to travel.