Methane Emission Estimates by the Global High-Resolution Inverse Model Using National Inventories
Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba 305-8506, Japan
Department of Climate Change, National Climate Center, Beijing 100081, China
Climate System Research, Finnish Meteorological Institute, 00560 Helsinki, Finland
Deutscher Wetterdienst, 63067 Offenbach, Germany
European Commission Joint Research Centre, 21027 Ispra, Italy
Earth System Research Laboratory, NOAA, Boulder, CO 80305-3328, USA
Institute for Atmospheric and Earth System Research (INAR)/Physics, Faculty of Science, University of Helsinki, 00560 Helsinki, Finland
Department Biogeochemical Systems, Max Planck Institute for Biogeochemistry, 07745 Jena, Germany
Author to whom correspondence should be addressed.
Remote Sens. 2019, 11(21), 2489; https://doi.org/10.3390/rs11212489
Received: 20 September 2019 / Revised: 18 October 2019 / Accepted: 22 October 2019 / Published: 24 October 2019
(This article belongs to the Special Issue Remote Sensing of Carbon Dioxide and Methane in Earth’s Atmosphere)
We present a global 0.1° × 0.1° high-resolution inverse model, NIES-TM-FLEXPART-VAR (NTFVAR), and a methane emission evaluation using the Greenhouse Gas Observing Satellite (GOSAT) satellite and ground-based observations from 2010–2012. Prior fluxes contained two variants of anthropogenic emissions, Emissions Database for Global Atmospheric Research (EDGAR) v4.3.2 and adjusted EDGAR v4.3.2 which were scaled to match the country totals by national reports to the United Nations Framework Convention on Climate Change (UNFCCC), augmented by biomass burning emissions from Global Fire Assimilation System (GFASv1.2) and wetlands Vegetation Integrative Simulator for Trace Gases (VISIT). The ratio of the UNFCCC-adjusted global anthropogenic emissions to EDGAR is 98%. This varies by region: 200% in Russia, 84% in China, and 62% in India. By changing prior emissions from EDGAR to UNFCCC-adjusted values, the optimized total emissions increased from 36.2 to 46 Tg CH4 yr−1 for Russia, 12.8 to 14.3 Tg CH4 yr−1 for temperate South America, and 43.2 to 44.9 Tg CH4 yr−1 for contiguous USA, and the values decrease from 54 to 51.3 Tg CH4 yr−1 for China, 26.2 to 25.5 Tg CH4 yr−1 for Europe, and by 12.4 Tg CH4 yr−1 for India. The use of the national report to scale EDGAR emissions allows more detailed statistical data and country-specific emission factors to be gathered in place compared to those available for EDGAR inventory. This serves policy needs by evaluating the national or regional emission totals reported to the UNFCCC.