The EU has emissions caps. Each year fewer and fewer carbon emissions rights are auctioned out.
https://ec.europa.eu/clima/eu-action/eu-emissions-trading-sy...
Maybe it doesn't yet reflect the externalities on the environment. But it eventually will. The 2030 target is set so that the EU becomes climate-neutral.
https://ec.europa.eu/clima/eu-action/climate-strategies-targ...
Until that time, I'll take the plane whenever I feel like it.