Topic summary
Greenhouse gas emissions by the United States
The United States produced 7 billion metric tons of carbon dioxide equivalentgreenhouse gas (GHG) emissions in 2025, the second largest in the world after greenhouse gas emissions by China and among the countries with the highest greenhouse gas emissions per person. In 2025 China is estimated to have emitted 29% of world GHG, followed by the United States with 12%, then India with 7%. In total the United States has emitted a quarter of world GHG, more than any other country. Annual emissions are over 15 tons per person and, amongst the top eight emitters, it is the highest country by greenhouse gas emissions per person.
The IEA estimates that the richest decile in the US emits over 55 tonnes of CO2 per capita each year. Because coal-fired power stations are gradually shutting down, in the 2010s emissions from electricity generation fell to second place behind transportation which is now the largest single source. In 2020, 27% of the GHG emissions of the United States were from transportation, 25% from electricity, 24% from industry, 13% from commercial and residential buildings and 11% from agriculture.
U.S. energy-related CO2 emissions decreased by 3% in 2023, amounting to a reduction of approximately 134 million metric tons (MMmt). This reduction primarily occurred in the electric power sector, with a significant shift from coal-fired power to less carbon-intense fossil fuels such as natural gas, as well as sustainable energy sources like solar.
In 2021, the electric power sector was the second largest source of U.S. greenhouse gas emissions, accounting for 25% of the U.S. total. U.S. greenhouse gas emissions are contributing to climate change in the United States, as well as worldwide.