Share of global greenhouse gas emissions 2021, by subsector

Global net greenhouse gas (GHG) emissions were 50.1 billion metric tons of carbon dioxide equivalent (GtCO₂e) in 2021. The largest overall contributor to global GHG emissions that year was coal-fired electricity, with 21 percent.  

Most polluting sectors

The power sector was the largest contributor to global CO₂ emissions in 2022, accounting for nearly 40 percent of the total emissions. Combined with transportation, these two polluting sectors were responsible for almost 60 percent of global CO₂ emissions that year. CO₂ accounts for roughly three-quarters of total greenhouse gas emissions. 

World's largest emitters

China accounted for 29 percent of global GHG emissions in 2022, making it the world's largest emitter. China's share of global GHG emissions was more than the combined shares of the U.S., EU-27, and India in 2022.