Global methane emissions from minor anthropogenic sources and biofuel combustion in residential stoves

Most global methane (CH4) budgets have failed to include emissions from a diverse group of minor anthropogenic sources. Individually, these minor sources emit small quantities of CH4, but collectively, their contributions to the budget may be significant. In this paper, CH4 emissions are estimated for a wide variety of individual minor emissions sources on a country-specific basis. Emissions from biomass combustion in the residential sector are also examined. The minor sources examined include fuel combustion in furnaces, vehicles, aircraft, ship, rail systems, industrial waste treatment and combustion processes, various industrial manufacturing processes (e.g., chemical manufacturing), on-site residential waste burning, forest wildfires, and prescribed burning activities, oil refining, and the storage/distribution of oil-derived products, coke production, and charcoal production. Country-specific emissions associated with residential wood, charcoal, and dung combustion are also estimated. The total annual CH4 emissions from all sources examined here are estimated to be about 40 Tg. Almost half of this total is due to residential fossil fuel and biofuels combustion.