We are pleased to inform you that the Global Carbon Project (GCP) has published an updated and expanded Global Methane Budget. For the decade of 2008-2017, global emissions of methane are 576 (550-594) Tg CH4 per year as estimated from atmospheric inversions (top-down approach). The global CH4 sink is 556 Tg (501-574) CH4 per year. The source–sink mismatch reflects, and is consistent with, the observed average imbalance in the atmosphere of 13 Tg (0-49) CH4 per year (the CH4 growth rate). The sum of all sources as estimated from inventories and modeling (bottom-up approaches) is 737 (594-880) Tg CH4, significantly higher than estimated from the top-down approach and reflecting the compounded uncertainties of the multiple CH4 sources.
The effort was supported by 91 contributors and 69 research organizations. Please find papers, data and additional resources at: https://www.globalcarbonproject.org/methanebudget