That isn’t true. The USA is a bigger producer of carbon per capita, but not pollution, which is defined very differently. This is why hebei cities have many AQI days above a normal 500 yet everyone freaks out whenever AQI in the states breaks 100 during a forest fire.

The EPA has never really bothered that regulate carbon, but they come down hard on the kind of air, water, and soil pollution that exists in China.

Should the USA do more about carbon? Ya, global warming sucks. But the EPA has solved the pollution problem that it was originally envisioned to solve.