Share of global greenhouse gas emissions 2023, by gas

Carbon dioxide is the primary greenhouse gas (GHG) emitted by human activities, and accounted for almost three-quarters of global GHG emissions in 2023. The main sources of CO₂ emissions are fossil fuel combustion from transportation and power generation. Meanwhile, methane contributed almost 19 percent to total GHG emissions. Although CO₂ is the most abundant GHG, methane has a higher global warming potential (GWP). Over a 100-year period, the GWP of methane is almost 30-times greater than that of CO₂. The main sources of methane emissions are enteric fermentation, natural gas systems, and landfills.