If you look at the history of pollution it isn't until recently that China started being a polluter on par with Europe and the US when we were growing our industry. Most of the pollution on earth hasn't come from China and if we acknowledge this and take our part in cleaning up, instead of pointing fingers and saying "today we are polluting less so you should too", we could for example lower import taxes on items made with green energy and lower export prices on things China need for going green(er).
China are not going to pay for fixing our pollution going back a hundred years. We are or China will just turn a deaf ear on our talk.
China is increasing their pollution. The issue is around leadership. How can the US lead China to lower pollution levels, something they are currently increasing?
The question on how to lead them doesn't point fingers. It doesn't ask China to cleanup any past mess done by others. Bringing this up avoids dealing with the very difficult issue of... how do outside parties lead China to be more environmentally friendly when they are increasingly going in the opposite direction.
Let me ask you this: If in scenario A the US (or EU) uses X billion dollars to lower pollution by tweaking an already high tech industry or in scenario B uses the same amount of money helping China getting their older technologies upgraded, which scenario do you think lowers the pollution the most?
If I could donate money and remove X amount of CO2 pollution from the US or X+10% from China with the same amount I would not care at all about national borders. Pollution doesn't. Nationalism does. Technology transfer for greener technology at a discount would help a lot more than trying to get some newer SUVs on the road in the States.
Btw. stating that China is "increasingly going in the opposite direction" is not fairly stating the situation. China is doing a lot better than most in many areas if you compare apples to apples. The main drive for the increase is the increase of people having access to something akin to what we have (smartphones, cars, etc). That a population being lifted out of poverty is polluting more than earlier isn't a surprise. They pollut more because they need more powerplants, more cars are on the road, etc. Not because the don't try to build efficient powerplants and don't try to tax old dirty cars.
China are not going to pay for fixing our pollution going back a hundred years. We are or China will just turn a deaf ear on our talk.