Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere. Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming.  Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid.
China used alternative fuels to generate electricity, while Mongolia burned lots of fossil fuels. There were frequent debates between the two countries on this matter.
Which country caused more global warming?