Earlier quoted context omitted.
I assume you're looking at overall CO2 emissions rather than per-capita emissions. The page you linked shows fossil CO2 emissions per capita: China: 7.7t CO2/cap/yr USA: 15.7t CO2/cap/yr Denver seems like a good place to give a speech. Of course, country size does matter, but it's unfair to simply compare total emissions when there's such a huge difference in population size.
If you're concerned with how guilty each individual consumer in a country should feel look at per capita emissions. If you're interested in stopping climate change effectively look at total emissions.
Well if you're concerned with effectively stopping climate change a quite important part of your calculation is where you can actually persuade people to address the issue. That's a complex calculation, but I think it's far more credible that you can get the policy supported in the US and then enforced internationally through treaties and negotiations with the support of Europe than trying to do a tour persuading China.