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As the world's largest CH 4 emitter, China's CH 4 emissions contribute to climate change more than the amount emitted by many developed countries combined. The rapid growth of China's coal demand has important implications for CH 4 emissions from coal mining or coal mine methane (CMM) emissions. This paper aims to present an overview of bottom-up estimation of China's CMM emissions, including the trend in the last four decades and the limitations of current understanding on CH 4 emissions. Although characterized by significant differences in inventory compilation, statistically, the total CMM emissions rose from 4.64 to 16.41 Tg with a peak of 21.48 Tg from 1980 to 2016. Large discrepancies of inventory results existed in previous studies, which were affected by the coverage of emission sources, emission factors and activity-level data. The disagreements can be largely attributable to the emission factors of underground mining, which contain substantial variances in both spatial and temporal dimensions. To develop more reliable CMM inventories and make targeted mitigation measures, more attention should be paid to the transparency of the estimated results, coal statistics, on-site CMM emission factors, and the emissions from abandoned coal mines. As the leading CH 4 emission source in China, the estimations of CMM emissions urgently need to overcome existing and emerging challenges for compiling a consistent and accurate inventory. Unlabelled Image • We perform an overview of current bottom-up estimation of China's CMM emissions. • CMM emissions over 1980–2016 rose from 4.64 to 16.41 Tg with a peak of 21.48 Tg. • Inventory results were improved along with large discrepancies and disagreements. • We discuss the types of emission source, emission factors and activity-level data. • The limits of current understanding and future research prospects are provided. [ABSTRACT FROM AUTHOR]

With the expansion of economic globalization and the growth of international trade, the pulling effect of household consumption to global anthropogenic CH 4 emissions related to production activities is becoming increasingly evident. This paper adopts a new perspective from the household-consumption side to investigate the CH 4 emissions of major economies in 2014 and compares it with the scenario under the final-demand-based perspective by combing the world input-output database and the latest emission data from the UNFCCC and EDGAR v5.0 database. Budgets of CH 4 emissions for 43 economies are established and trade connections & balances among major economies are explored. Results show that consumption-driven economies are allocated more CH 4 emissions in the household-consumption-based accounting (HCBA) framework compared to the final-demand-based accounting (FDBA) framework. The total trade-related transfer of CH 4 emissions is shown to sum up to 19% and 27% of the global total under the HCBA and FDBA frameworks, respectively. The household-consumption-based CH 4 emissions of China, India, Indonesia and Mexico are much lower than their final-demand-based CH 4 emissions, while the converse is true for the United States, Russia, Japan, the United Kingdom and Germany. The new accounting framework provides a new view to understand trade-related CH 4 emissions of major economies and to identify the role of household consumption in global supply chains, offering important implications for greenhouse gas emission mitigation. Unlabelled Image • Latest CH 4 emission inventories for major economies in 2014 are provided. • Household-consumption-based accounting of CH 4 emissions is firstly conducted. • The findings are compared with those under the final-demand-based accounting. • Consumption-oriented economies should take more responsibility for CH 4 reduction. [ABSTRACT FROM AUTHOR]

As "the world's factory", China's energy consumption and GHG emissions can be largely attributed to its manufacturing economy. This paper aims to examine energy-related methane (CH 4) and carbon dioxide (CO 2) emissions by Chinese economy from a consumption-based perspective, and to explore the energy-climate-manufacturing nexus relationship in its supply chains. Nearly three-quarters of China's energy-related GHG emissions in 2012 were associated with the manufacturing industry directly or indirectly. Among which, over two-fifths of the national CH 4 and CO 2 emissions were embodied in the final demand of manufacturing products, mainly driven by the exports and capital formation. Meanwhile, manufacturing sectors served as important intemediate transmission nodes of embodied emissions for other industries such as construction and services. More than 80% and 40% of the embodied emissions in the sectors of construction and services were related to the intermediate uses of manufacturing products, respectively. Critical supply chain paths for linking embodied GHG emissions with manufacturing sectors were extracted through the structural path analysis technique. The top 30 common paths were responsible for about one fifth of the total CH 4 and CO 2 emissions. Three main transmission nodes of embodied energy-related GHG emission flows were identified. While approximately half of the energy-related CH 4 emissions occurred at the fourth or higher production layers, the CO 2 emissions were distributed evenly across the production layers. Mitigating energy-related GHG emissions associated with manufacturing economy by adjusting critical industrial sectors and final demands provides new insights for understanding the transitions of China's manufacturing industries to a low-carbon economy. Unlabelled Image • 75% of China's energy-related GHG emissions were related to manufacturing sectors. • Over 40% of the emissions were embodied in final demand of manufacturing products. • Energy-climate-manufacturing nexus relationships and structural paths are explored. • The co-control of CH 4 and CO 2 emissions call for actions on entire supply chains. [ABSTRACT FROM AUTHOR]