Major expansion in air transport will continue, especially as roads and railways get clogged up and people become increasingly mobile. There is no "putting the genie back in the bottle" as the green lobby would like to see.
There is a difference between our desire to keep visiting new places and a need to get there quickly and to do so in person.
So even if you put the green lobby to one side - something neither the current nor past lot are showing any likelihood of doing - you do still need to find an energy source for all this travel.
You are right about new oil finds, but demand is also rising across Asia and South America, so they have to keep drilling. Synthetics or biofuels are still at some premium, whereas the cost of renewable electricity production is likely to keep falling.
So I agree that we may well still see some expansion over time, but I'm not so sure about the major.
Someone somewhere must have done some robust models on this - shove in oil upto $1000 a barrel or wherever, play with the economy, populations and so on.
At the top end, Concorde has gone and not been replaced. I suggest the most urgent communications can now indeed be done by video conferencing and so on.
I don't think for one minute that people will stop travelling for business or pleasure, but they will accept different ways of getting there.
We've already seen a lot of internal flights moved over to rail within England. To suggest that the rails are too crowded whilst at the same time saying we need airport expansion is a completely inconsistent argument.
Unfortunately, the government's line that we can meet future demand at Heathrow by building a high speed line to places where rail already dominates the market is even more inconsistent.
However, with a big enough crystal ball and a long enough timeline, the answer must surely lie with maglevs - once they become as fast as flying and cheaper to build than motorways or high speed railways. Which might be sometime at the latter end of the
next 50 years!