If we do become serious about it, there's no reason internal flights that can easily be replaced by slower rail today, shouldn't be pay as high taxes for fuel, as the cars do.
Cars can also be more convenient than transit, and we tax them for it.
Well, it is not taxed because it is convenient. It is taxed because of the huge negative externalities it brings with it.
That's why we need to make the worse method more expensive, so price sensitive buyers don't go for that one.
Talk to the engineers to figure out how much it would cost to capture that natgas. Set the fine for flaring natural gas to be that, + $10,000 or so per day.
Voila! Suddenly it's economical to capture that natgas.