Just for reference China has about 17% of the world's population, and India has about 18%.
China has also been deploying lots of renewable and nuclear energy, and their carbon emissions actually falling.
Solar and wind have gotten so cheap we should be able to forgo more fossil fuel deployment in developing nations.
China CO2 emission increased a lot over the last 20 years and it is growing every years. Not decreasing but increasing. The IEA estimate says China’s CO₂ emissions reached 12.6 Gt in 2023, up 4.7% from 2022.
On the other hand U.S. CO₂ emissions decreased slightly between 2022 and 2023. About 2–3% (from 4.79 to 4.68 Gt)
[1] https://www.iea.org/countries/china/emissions
And then in 2025 it was exactly the other way around. China's emissions decreased, the US's increased.
https://news.ycombinator.com/item?id=45108292