Methane is a potent greenhouse gas that has about 30 times the impact on global warming per unit mass compared to carbon dioxide over a 100-year lifetime (83 times larger over 20 years). Methane is responsible for 0.5°C of today’s warming representing ~30% of total human-caused warming.1
![]()
The concentration of atmospheric methane reached 1922 parts per billion (yearly average) in 2023. This is an increase by a factor of 2.6 compared to the pre-industrial level (722 parts per billion) and the highest value in at least 800,000 years.2
Methane concentrations increased continuously throughout most of the 20th century, primarily driven by anthropogenic industrialization. The rate of increase slowed in the 1990s, and in the early 2000s concentrations appeared to plateau. But beginning in 2007 methane concentrations rose sharply. The highest rate of change in the 40-year observational record occurred between 2020 and 2023.3 Rising methane concentrations oppose any effort to mitigate climate change.
![]()
Scientists turn to assessments such as the global methane budget to guide their investigation of the sources for the rise in concentrations.4 Anthropogenic sources include fugitive methane emissions from fossil fuel supply chains, enteric fermentation by ruminants, landfills, rice cultivation, wastewater handling, and manure management. Natural sources include wetlands and inland water systems, termites, oceans, fire, and geologic sources.
The latest global methane budget introduced a new category for ‘indirect anthropogenic emissions,’ which includes elevated methane emissions from human-made reservoirs, nutrient-enriched water bodies such as ponds and lakes, and wetlands experiencing warming due to climate change
Scientists have offered several explanations for the recent rapid increase, including rising anthropogenic emissions from agriculture, landfills, and biomass burning; changes to the atmospheric sink for methane; and increasing emissions from natural sources such as wetlands.5
