Global carbon dioxide emissions 2010-2023, by select country

In 2023, China was the biggest carbon polluter in the world by far, having released 11.9 billion metric tons of carbon dioxide (GtCO₂). Although the U.S. was the second-biggest emitter, with 4.9 GtCO₂ in 2023, its CO₂ emissions have declined by 13 percent since 2010. By comparison, China’s CO₂ emissions have increased by more than 38 percent in the same period. 

Cumulative emissions

Although China is currently the world's largest carbon polluter, the U.S. has released far more historical carbon dioxide emissions, at more than 400 GtCO₂ since 1750. The wide gap between the two countries is because China's emissions have mostly been produced in the past two decades. Combined, the U.S. and China account for roughly 40 percent of cumulative CO₂ emissions since the Industrial Revolution began. 

Sources of emissions

One of the largest sources of global CO₂ emissions is the power sector, with electricity produced by coal-fired power plants a significant contributor. In China, emissions from coal-fired electricity generation have soared since the turn of the century, and reached 5.2 GtCO₂ in 2023.