In Greece, with the new rules, the Environmental tax is going to be November until end of March --> 2 Eur, and April until end of October --> 8Eur.
Even if I change it in the system manually, it is not working, as I may get a reservation in December for coming June for example.
I think airbnb should add a setting in the platform that allows you to adjust the additional taxes per period just like you can do with the prices.
In the past that was 0,5Eur low season and 1,5Eur high season. It was not that high and as a host you could "absorb" the difference.