The point isn't changing other countries. The point is giving competing green technologies a fighting chance.
I don't care whether Saudi Arabia suffocates in cheap oil or builds a hi-tech green energy paradise. That's their choice. But I don't want the local green energy startups and organic farms be driven out of business by cheap Saudi-Arabic oil. Same with China - I think it's fundamentally unfair that local businesses have to abide to many regulations (e.g. environmental, safety, hiring) that Chinese companies don't need to, yet they are able to compete in the same market offering lower prices.
I think that the current implementation of free trade is a fundamentally failed and morally wrong model.
China's population is 4.3 times that of the USA, but they only burn 1.3 times as much coal. In other words, the average American burns nearly 4 times as much coal as the average Chinese person.