“If you put your gun down, I’ll put down mine.”
The problem with this logic is that if no one yields, both end up shooting each other and no one wins.
Here’s how this situation is different: China not only showed up, but took a few bullets out of the gun to convince the US to put their guns down.
They did set a few ground rules, one of which being that they cannot be put on the same level as richer nations (i.e. the US).
This was a deal breaker for the US when the Kyoto Protocol was on the table more than a decade ago. However, considering the US has less than one-third the population of China and considerably higher living standards for the vast majority of its citizens, I find this to be a fair consideration in greenhouse gas emissions discussions. However, if China was really smart, they’d take a page from Germany’s book and build their economy off green energy.