In an article by Xiaoqi Zheng, Dag Hessen and others decompose the main drivers and the trends of the largest CO2 emitter in the world. While increased population size and economic growth (per capita GDP) contributed to a rise in CO2, improved energy efficiency and reductions in carbon intensity buffered to some extent China's emissions. While implemented policies have already managed to tame current CO2 output given China's economic growth, more has to be done, and China needs to transform to low-carbon energy systems.
Read more about the complex interactions between economy, population growth and CO2 emissions of the largest CO2 emitter in the world.
You can also read about the topic in a related Aftenposten article by Dag Hessen and Nils C. Stenseth.