While I agree with everything else, I am not sure, why everyone has always to mention absolute numbers to China's CO2 production. China ist also the most populous county in the world. And the its CO2 emission per capita for 2008 is on par with Sweden or Israel and less than third of the US one (http://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita).
Unless one argues that the Chinese people are less valuable than the US citizens (you can't even tell them from one another!), I don't see, how one can critisise China without being a hypocrite. That goes not only to the US, Germany, France and half of the developed world in worse in that regard.
Of course, if China was to provide an equal living standard to every citizen, the situation would be entirely different. And you can surely use some metric like CO2-emission/GDP, where China would look quite terrible and make a valid argument about their efficiency. But right now, China as a whole is more CO2-free than most of the developed countries.