In my opinion, through a combination of interdependent factors:
- emissions trading
- taxes
- voluntary capacity restraint by airlines
- some ‘conscience-driven’ changes in the market
the amount of air travel in x years will be y% lower than it would otherwise have been. Which means ~y% fewer jobs than there would otherwise have been.
There will still be jobs, possibly more than there are today as the industry could still grow, albeit at a much slower rate. It’s also entirely likely that much of the y% will come through weaker airlines quitting the market, leaving the survivors stronger. Who knows? T’n’Cs might even improve.