Share of greenhouse gas emissions in the U.S. 2021, by gas
Carbon dioxide is the primary greenhouse gas emitted by human activities in the United States, accounting for 79.4 percent of the country's total greenhouse gas emissions in 2021. The main sources of CO₂ emissions are fossil fuel combustion from transportation and power generation.
Methane represented 11.5 percent of U.S. GHG emissions that year. Although CO₂ is the most abundant GHG, methane is more effective at trapping heat in the atmosphere. The main sources of methane emissions in the U.S. are enteric fermentation, natural gas systems, and landfills.
Methane represented 11.5 percent of U.S. GHG emissions that year. Although CO₂ is the most abundant GHG, methane is more effective at trapping heat in the atmosphere. The main sources of methane emissions in the U.S. are enteric fermentation, natural gas systems, and landfills.
