The right hon. Gentleman will know that the whole history of airline travel hitherto has been that it increases exponentially. It has done so, and if allowed to do so, will continue.
So I do not share this cosy consensus. I am not part of the airline and airport love-ins. As Members will know, airlines and their passengers already get a huge subsidy because of the low price they pay for airline fuel—kerosene. Members ought to bear this in mind when debating APD: no doubt the figures are lower in Scotland, but across the UK in any given year half the population do not fly. I believe that hon. Members have a completely distorted view of this matter. I suspect that I am one of the very few Members of this House who does not fly; I have not flown for years. I suspect that every other Member has a distorted view, based on self-interest. [Interruption.] It is not me who is causing a huge amount of environmental degradation through flying. The greenhouse gases emitted by aeroplanes at high altitude are far more damaging than the same amount of greenhouse gases emitted at sea level. Air travel is the most polluting form of mass travel.
In that context, I regret that the Government are devolving air passenger duty. Yes, I would increase it. The UK Government will live to regret this measure, because we are clearly heading towards the abolition of air passenger duty in Scotland and, eventually, through a process of “beggar my neighbour” downwards, across the rest of the United Kingdom. That will be another nail in the coffin of the doomed and uneconomic HS2 railway line. People will continue to fly south from Scotland and the north of England, and vice versa, rather than using the HS2 line. It is already uneconomic and, with the abolition of air passenger duty, it will become even more so.