Comment by Arainach
We could start by banning things that explicitly waste resources such as proof of work cryptocurrency and adjust tax incentives to punish huge energy consumers for things like AI. Make the energy cost factor in the long-term externalities and maybe companies will hesitate before burning the world for things that aren't necessary.
Things don't have to be perfect - you start with the biggest polluters/consumers and use trade incentives to convince other nations to join. We've seen this work under Democratic administrations (China's outputs are dropping) before Trump etc. threw it all away.
China turning the corner on emissions has far more to do with their desire to get out from under the possibility of an oil blockade locking up their economy than green pressure from the west. They also organically have an environmental movement, though not one that they are willing to kowtow to at the cost of growth.