Global Methane Budget 2000-2012 (V.1.0, issued June 2016 and V.1.1, issued December 2016)

After carbon dioxide (CO2), methane (CH4) is the second most important well-mixed greenhouse gas contributing to human-induced climate change. In a time-horizon of 100 years, CH4 has a Global Warming Potential (GWP-100) 28 times larger than CO2. The level of CH4 in the atmosphere is over 150% higher than pre-industrial times (cf. 1750), and it is responsible for 20% of the global warming produced by all well-mixed greenhouse gases. Methane is transformed into water vapor in the stratosphere. Methane also produces ozone in the troposphere, which is a pollutant with negative impacts on human health and ecosystems. The atmospheric life time of methane is 10 ± 2 years. [Copied from the Global Carbon Project, Global Methane Budget Highlights at http://www.globalcarbonproject.org/methanebudget/16/hl-compact.htm To access the older version of this data package see: http://cdiac.ess-dive.lbl.gov/GCP/methanebudget/2016/