Tell that to the millions of people in concentrations camps because they practice the wrong religion or were born into the wrong ethnic group.
China also produces more carbon dioxide emissions than the US and Europe combined and it's growing at a faster rate, so I don't think you can say that the Chinese model is offering up a better solution for climate change.
Not sure I'd take that definition of success. China seems like an absolute failure in the face of almost certain success. The CCP seems to ruin every good thing about the Chinese culture, suppress every positive instinct, and punish every decent behaviour. They absolutely do not care about your silly environmental causes, and if you got in the way of any one of their state-sponsored ecological disasters, you would be crushed like roadkill.
I think nuclear power generation is an excellent idea, but if it is somehow incompatible with representative democracy, there just isn't an option, I guess we have to find some other good way to generate power. Though I think the idea that the two are incompatible is nonsense.
On the other hand, not getting nuclear power deployed ASAP everywhere essentially means the long term destruction of our planet.
So all in all, I don't think it's nearly as clear cut a decision on nuclear vs. democracy, and if forced to choose I may pick the former.