> If you want to reduce air travel for environmental reasons, then tax it more.

> Shaming individuals doesn't seem to be productive or helpful.

First, none of us have any power to "tax it more" so this is a dead end of discussion. Second, people have agency and we can hold them accountable socially for negative actions even if they are abiding by the current laws (or tax regime). This happens all the time, because laws don't fully align with morality in a culture. Suggesting that we should leave such things to the sole discretion of the economy and taxes describes a strange unhuman-like society that we don't live in.