"Taxes don't reduce emissions.

Yes they do, provided they are sufficient to create demand destruction. People don't fly places because they need to. They do it because they want to, and because it is fast and cheap. Cheaper than train in many cases. The airline industry need to shrink. The last thing we need is for it to grow, 'as projected', or hoped. Some airlines will go out of business. That's al right. They are not needed, and incredibly wasteful. So, recipe for the airline industry "in crisis": Increase ticket prices, reduce number of flights, lay off personnel no longer needed. It's not rocket science, damn it.