The global airline industry has long warned passengers they’ll eventually have to pay some of the $5 trillion cost of decarbonizing air travel. The moment has come.

Singapore’s government has announced a tax on air fares to fund purchases of pricey sustainable aviation fuel, while neighboring Malaysia has authorized carriers to charge people a carbon levy from next month.

In Europe, airlines this year lose one quarter of their free emissions allowance, the first in a series of reductions that’s already estimated to be adding to ticket prices.