You need to look at the trends. For many decades China built up fossil fuel production and use as fast as possible, and didn't give a damn about the environment

You need to look at the trends. For many decades China built up fossil fuel production and use as fast as possible, and didn't give a damn about the environmental consequences. But then about a decade ago, the government suddenly realized it needed to get off fossil fuels, for a whole series of reasons (one of them being that, unlike American conservatives, Chinese governmental officials actually believe what their scientists tell them). So China has been busy turning around the huge ocean liner of its economy as fast as it can, and the result is a great improvement in the first and second derivative of fossil fuels pollution (though a recent slowdown in the economy has also helped here).