I'm more concerned about soil pollution and sinking water tables in the most fertile regions. Air could be cleaned up in a week, but this can't.

Improper irrigation can even lead to salts rising up to the soil surface and making it permanently infertile barring major earth works. Falling water tables can allow the ground to compress (now-empty pores deflate) and significantly lower the ground's ability to carry groundwater (as has happened in California).

Some damage is permanent, and we were not capable of the worst back then.

My list wasn't about China being evil or "worse than the US". I wish them well but the combination of problems they false has sufficient to make their economy stall. And with a stalled economy, China will have a hard time affording a Clean Air Act, adding to the vicious cycle they are experiencing.

Further, repression also make the equivalent of a Clean Air Act hard. The pattern currently is the central authorities issue a call to protect the environment (usually kind of ad-hoc) but local authorities ignore it and no one can complain because all the authorities are beyond criticism.

Just like the way you have the President start an anti-corruption campaign but the President's cronies exempt.

China boosters for years said these problems didn't matter. Maybe they didn't matter for those years but now, they are here in spades.