China’s regional CH4 emissions: Characteristics, interregional transfer and mitigation policies

Methane (CH4), the second largest greenhouse gas emitted in China, hasn’t been given enough attention in the country’s policies and actions for addressing climate change. This paper aims to perform a bottom-up estimation and multi-regional input–output analysis for China’s anthropogenic CH4 emissions from both production-based and consumption-based insights. As the world’s largest CH4 emitter, China’s total anthropogenic CH4 emissions in 2010 are estimated at 44.3 Tg and correspond to 1507.9MtCO2-eq by the lower global warming potential factor of 34. Energy activities as the largest contributor hold about half of the national total emissions, mainly from coal mining. Inherent economic driving factors covering consumption, investment and international exports play an important role in determining regional CH4 emission inventories. Interregional transfers of embodied emissions via domestic trade are equivalent to half of the national total emissions from domestic production, of which two thirds are energy-related embodied emissions. Most central and western regions as net interregional CH4 exporters such as Shanxi and Inner Mongolia have higher direct emissions, while the eastern coastal regions as net interregional importers such as Guangdong and Jiangsu always have larger embodied emissions. Since China’s CH4 emissions have significant contributions to global climate change, a national comprehensive action plan to reduce CH4 emissions should be designed by considering supply-side and demand-side emission characteristics, mitigation potentials and emission responsibilities.