This paper presents estimates of current and future global anthropogenic methane emissions, their technical mitigation potential and associated costs for the period 2005 to 2030. The analysis uses the GAINS model framework to estimate emissions, mitigation potentials and costs for all major sources of anthropogenic methane for 83 countries/regions, which are aggregated to produce global estimates. Global anthropogenic methane emissions are estimated at 323 Mt methane in 2005, with an expected increase to 414 Mt methane in 2030. Major uncertainty sources in emission estimates are identified and discussed. Mitigation costs are estimated defining two different cost perspectives; the social planner cost perspective and the private investor cost perspective.