The key word is global, though. Greenhouse gas doesn't just float above the country it was produced in, it is a global thing. Literally every industrial power has to cooperate in ceasing production of greenhouse gases. I'm just doubtful we can get China to agree.
The US has a lot of leverage in this world, which the US can use to its advantage. It can for example, declare that China's greenhouse gas emissions are too high to reasonably accept, and they could put a sanction on trades and exports until they shut down the majority of their coal plants. (Yes, I'm aware this would hurt the economy. No, I'm not an economic expert by any definition of the word, but it's a small price to pay to save the world.) Do note, though, that they are building more renewable energy. For example, they just dammed one of the worlds largest rivers to make the largest hydroelectric dam ever. 22Gigawatts of power. They're also making nuclear power, lots of it, as I said. That could be enough to make a difference assuming they shut down their coal plants.