China population = 1.398 billion
U.S. population = 328.2 million
So the U.S. has around 25% of China's population and yet produces 50% of China's CO2 emissions. Makes one wonder what ours would be if we had one billion more people.
China is the largest emitter of carbon dioxide gas in the world, with 10.06 billion metric tons in 2018. The primary source of CO2 emissions in China is fossil fuels, notably coal burning. About 58% of the total energy derived in China comes from coal alone, and since coal is rich in carbon, burning it in China's power and industrial plants and boilers releases large amounts of CO2 into the atmosphere.
The U.S. is the second-largest emitter of CO2, with approximately 5.41 billion metric tons of carbon dioxide emissions in 2018. The largest sources of CO2 emissions in the U.S. comes from power generation, transportation, and industry. Even though the U.S. government undertook significant efforts to reduce the reliance on coal for electricity generation, the country has become a major producer of crude oil.
The 5 Countries That Produce the Most Carbon Dioxide (CO2)
Edit...
Lets break it down per person like they do the national debt...
China...
10.06 billion metric tons of CO2 ÷ 1.398 billion people = 7 metric tons per person.
United States
5.41 billion metric tons of CO2 ÷ 328.2 million people = 16.4 metric tons per person.
So hypothetically if the U.S. had China's population....
16.4 x 1.398 billion = 22.927 billion metric tons of CO2 per year