Zhao Min, Tian Xiangjun, Wang Yilong, Wang Xuhui, Ciais Philippe, Jin Zhe, Zhang Hongqin, Wang Tao, Ding Jinzhi, Piao Shilong
State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China.
University of Chinese Academy of Sciences, Beijing 101408, China.
Natl Sci Rev. 2024 Jun 26;11(8):nwae223. doi: 10.1093/nsr/nwae223. eCollection 2024 Aug.
The unprecedented surge in global methane levels has raised global concerns in recent years, casting a spotlight on China as a pivotal emitter. China has taken several actions to curb the methane emissions, but their effects remain unclear. Here, we developed the Global ObservatioN-based system for monitoring Greenhouse GAses for methane (GONGGA-CH) and assimilate GOSAT XCH observations to assess changes in China's methane emissions. We find the average rate of increase in China's methane emissions (0.1 ± 0.3 Tg CH yr) during 2016-2021 slowed down compared to the preceding years (2011-2015) (0.9 ± 0.5 Tg CH yr), in contrast to the concurrent acceleration of global methane emissions. As a result, the contribution of China to global methane emissions dropped significantly. Notably, the slowdown of China's methane emission is mainly attributable to a reduction in biogenic emissions from wetlands and agriculture, associated with the drying trend in South China and the transition from double-season to single-season rice cropping, while fossil fuel emissions are still increasing. Our results suggest that GONGGA-CH provides the opportunity for independent assessment of China's methane emissions from an atmospheric perspective, providing insights into the implementation of methane-related policies that align with its ambitious climate objectives.
近年来，全球甲烷水平前所未有的激增引发了全球关注，使中国成为关键排放国备受瞩目。中国已采取多项行动来遏制甲烷排放，但其效果仍不明朗。在此，我们开发了基于全球观测的甲烷温室气体监测系统（GONGGA-CH），并同化GOSAT柱浓度观测数据以评估中国甲烷排放的变化。我们发现，与前几年（2011-2015年）（0.9±0.5 Tg CH/年）相比，2016-2021年期间中国甲烷排放的平均增长率（0.1±0.3 Tg CH/年）有所放缓，这与全球甲烷排放的同步加速形成对比。结果，中国对全球甲烷排放的贡献显著下降。值得注意的是，中国甲烷排放的放缓主要归因于湿地和农业生物源排放的减少，这与中国南方的干旱趋势以及双季稻向单季稻种植的转变有关，而化石燃料排放仍在增加。我们的结果表明，GONGGA-CH为从大气角度独立评估中国的甲烷排放提供了机会，有助于深入了解符合其雄心勃勃气候目标的甲烷相关政策的实施情况。
