Kurzgesagt has a good video called "Who Is Responsible For Climate Change? – Who Needs To Fix It?":
* https://www.youtube.com/watch?v=ipVxxxqwBQw
There are multiple view points. The country with the largest current annual total emissions is China with 27-30% and the US with 15% (see 2m10s).
The country that produced the most CO2 in total historically which got us to this point of climate change (see 3m30s), were US first at 25% of historical emissions, and the EU in second at 22%, and China in third with 13% of historical emissions. India, all of Africa, and all of South America each had 3% of historical emissions.
Then there's per capita emissions (see 5m10s of the video).
So which of these three metrics should be used? Or should it be some other metric or a combination?
Also probably worth noting that China seems to have peaked in coal plants. They've built too many already, but hopefully it should be going down now.