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.
Context: 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.
Question: Which country caused less ocean acidification?