Ideally there are alternatives to flying, but it's not a requirement: as long as flying has an environmental price, recovering it through tax is a decent logic.
We can discuss the offered price, or how the tax could be structured, but I don't think the approach is unreasonable on its face.
The money collected with this tax may or may not reduce air travel and will be spent on government employees, welfare distributions, healthcare, roads, military etc as all other taxes and only a fraction will be spent on improving the environment.
I’ll be traveling via barge for the foreseeable future because of this tax.
IMHO, though, the tax should be just enough to neutralize that incentive. Anything more and you are selectively penalizing one industry, which I don't think is fair. Airlines didn't invent the concept of burning fuel to power machinery; society did, chose it as the basis for all industrial technology, and used it for everything. Air travel is just one thing on that list.
Also, the airlines were not the only ones who benefited. More or less, we all did. If ticket prices always included the carbon cost, then your business would have had to pay a higher price to fly you to that business meeting. And you would have had to pay a higher price to go on that vacation or visit those relatives.
We all had a party and trashed the place. We should all clean it up together.
So far that reason, to the extent that we can fix things with government action (funding research, etc.), I think the costs should be taken that out of the general fund. That not only everyone pays for what everyone benefited from, it also means it can be progressive and have other attributes of good tax policy.
This is a good point, actually ...
If the tax is punitive enough that it results in a meaningful decrease in miles flown then it has a positive environmental impact, but it's difficult to imagine the taxes being that punitive. That's probably politically impossible.
In order for this to "recover" something, as is being discussed, you'd need a way to convert these dollars into carbon sinks of some kind - which isn't, itself, without controversy ...
I am personally in favor of removing subsidies to air travel and increasing taxes on miles flown such that the impact would be noticeable, but again, that's a tall order, politically.
But any new project requiring significant financement needs to propose actions to balance its cost to get approved, thus in this instance the project to invest in roads and rails is backed by this tax.
The projected tax amount just needs to be roughly the same as the new project’s cost.
Or maybe you mean that if it's only NL and France it will just bankrupt KLM/AirFrance while it is's EU-wide it will bankrupt them all.