This article conflates global greenhouse gas concentrations with local air pollution. The idea that the communist party of China cares so much about the global environment to actually do something about climate change, but won't even clean up the local air pollution in its major cities that drastically reduce the immediate quality of life of their citizens is absurd.
Talk is cheap. China isn't reducing green house gas emissions one iota. However, China's leaders are smart and will put pressure on the USA to do so in order to give an advantage to Chinese manufacturers. Trump is calling them out on their hypocrisy. China wasn't the first to push global warming for financial gain, but they sure will if our leaders are stupid enough to let them get away with it.