The market will adapt, and yes the fares will go up and those who can't afford to go will stop going, go less often or go less often but stay for longer. (which is no different to many other things in life which I can't afford to do ,or have, at all or as often as I would like). Those with money will continue to do pretty much as they please, like now, and continue to do things that I can't afford. So?Well for a start its going to be very difficult to to have a debate on that without dealing with both who you are going to restrict from flying, and how you deal with the economic consequences of fewer people travelling to countries that rely on the tourism industry, which is pretty much the same debate as how to deal with a full ban.
Secondly you have been dancing around the latter subject like a politician in front of a Parliamentary committee, which makes me wonder exactly why. Because from experience when challenged on such matters, I've generally found those in favour of total bans or severely curtailing flights tend not to want to deal with the awkward issue such policies would leave behind. Furthermore I'm pretty sure that most people realise that curtailing flying will end up involving some kind of taxes, increase in fares or a "credit" system, none of which will not regular flyers as they can afford those or will be able to circumnavigate them, leaving the lowest paid once again paying the price in not being able to travel as easily. So unless there's another way that both has minimal impact on economies around the world, and doesn't lead to what will be travel restrictions for those on lower incomes, then frankly there's little to debate that hasn't been already.
Yes, some places will become economic backwaters again (at least as far as tourism is concerned), and we'll go to the beaches of Belgium or Normandy (again). The Maldives will be glad that their islands stop disappearing, but they won't get many tourists either.
Won't happen overnight, just a gradual change as flights get more expensive....