Absolutely not... who gets to decide what reason is good enough to fly? How about instead of reducing freedom we stop externalizing these costs, no matter their purpose or industry?
Just set up a carbon tax that is tied to the cost of removing carbon from the atmosphere and everybody can decide for themselves whether they want to pay or not.
The flipside to that is why should wealth be the determining factor?
Suppose I'm poor but need to travel to another city to get medical treatment to save my life -- but a global carbon-tax prevents me. In contrast someone who happens to have been born to a rich family in a rich country goes around the World because they're bored.
Sure, that's a purposefully extreme example, but it's necessarily so.
Is that situation morally superior to you? Is it fair, desirable?
If we were organising things on a global scale we might give every person carbon credits. But that would be a massive redistribution of wealth.
What strikes me is we're going to need to normalise around a lower consumption lifestyle or vastly reduce the population.