I thought it wasn't a problem, but now it's China's problem? That's a very quick change of pace.

As an American, you directly emit a lot more greenhouse gas than a Chinese person does. More, that doesn't take into account the emissions from all the goods you buy from China.

China's per capita emissions are a fraction of America's, and unlike America, they have committed to a very aggressive program of decarbonization.

https://en.wikipedia.org/wiki/Greenhouse_gas_emissions_by_China

I live in the Netherlands, but that doesn't give me a right to emit more crap into the atmosphere because I live in a tiny country. You shouldn't get to emit a lot more crap into the air than a Chinese person, no matter what country you live in.