I'm relatively hopeful that renewables will simply be cheaper though, in part thanks to China. But we could still use tariffs for global co-operation on other sources of emissions (there was a story recently about China releasing CFCs for example).
A sort of reparation or settlement for western carbon output in the 20th century, which the same impact on the climate only differing in happening earlier, would help developing nations get on board. This arrangement could take the form of investment in a developing nations clean energy infrastructure or compensation in other forms.
Otherwise, developing nations besides China will probably continue buying legacy, retired coal fire equipment from China, which has been happening for some time now.
But the hypocrisy argument fails anyway because the renewable alternatives that exist today didn't exist a hundred years ago. It's altogether different to choose coal when the science is less well understood and no viable alternatives are known to exist than to do so today when that is not the case.
There is also a difference in scale. There are more than four times as many people in the developing world as there are in the developed world. If they used the same amount per capita then they would release more carbon in 10 years than we did in 40. Even if the First World hadn't burned an ounce of coal, they still wouldn't be able to do what we actually did. But they also don't need to today.
And it would be easier to pass tariffs than convince the population of the First World to send their money overseas. This needs to happen right now, not after people argue about it for another twenty years.
Unfortunately, China appears to have some historical inertia and perverse incentives to keep mining coal and building/running coal plants even if coal-fired electricity isn't the cheapest any more [1]. The incentives to keep running economically dubious coal plants to maintain employment can be very strong in some provinces, even if that conflicts with national goals for reducing air pollution. Mining coal and running coal plants requires more workers per megawatt hour than solar power. And even if they were equal, it's not like coal miners can painlessly make the transition to working in solar manufacturing or installation.
I have also read about situations where e.g. a province gets revenue for every ton of coal mined, but would not get any revenue for every hour of sunshine collected, so there are localized revenue reasons for provincial authorities to prefer coal.
[1] Like Germany, Australia, the US, Poland, South Africa... and more.