College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China; State Key Joint Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China; Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, MA, 02139, United States.
Environ Res. 2024 Oct 15;259:119549. doi: 10.1016/j.envres.2024.119549. Epub 2024 Jul 2.
Methane (CH) is the second most abundant greenhouse gas. China is the largest CH emitter in the world, with coal mine methane (CMM) being one of the main anthropogenic contributions. Thus, there is an urgent need for comprehensive estimates and strategies for reducing CMM emissions in China. However, the development of effective strategies is currently challenged by a lack of information on temporal variations in the contributions of different CMM sources and the absence of provincial spatial analysis. Here, considering five sources and utilization, we build a comprehensive inventory of China's CMM emissions from 1980 to 2022 and quantify the contributions of individual sources to the overall CMM emissions at the national and provincial levels. Our results highlight a significant shift in the source contributions of CMM emissions, with the largest contributor, underground mining, decreasing from 89% in 1980 to 69% in 2022. Underground abandoned coal mines, which were ignored or underestimated in past inventories, have become the second source of CMM emissions since 1999. From 2011 to 2022, we identified Shanxi, Guizhou, and Shaanxi as the three largest CMM-emitting provinces, while the Emissions Database for Global Atmospheric Research (EDGAR) v8 overestimated emissions from Inner Mongolia, ranking it third. Notably, we observed a substantial decrease (exceeding 1 Mt) in CMM emissions in Sichuan, Henan, Liaoning, and Hunan between 2011 and 2022, which was not captured by EDGAR v8. To develop targeted CMM emission reduction strategies at the provincial level, we classified 31 provinces into four groups based on their CMM emission structures. In 2022, the number of provinces with CMM emissions mainly from abandoned coal mines has exceeded that of provinces with mainly underground mines, which requires attention. This study reveals the characteristics of the source of CMM emissions in China and provides emission reduction directions for four groups of provinces.
甲烷（CH）是第二丰富的温室气体。中国是世界上最大的 CH 排放国，煤矿甲烷（CMM）是主要人为排放源之一。因此，迫切需要对中国的 CMM 排放进行全面评估并制定减排策略。然而，由于缺乏不同 CMM 源时间变化的信息以及缺乏省级空间分析，有效的策略制定目前受到挑战。在这里，我们考虑了五个来源和利用方式，构建了中国 1980 年至 2022 年 CMM 排放的综合清单，并在国家和省级层面量化了各个来源对整体 CMM 排放的贡献。我们的结果突出了 CMM 排放源贡献的重大变化，最大的排放源——地下开采，从 1980 年的 89%下降到 2022 年的 69%。自 1999 年以来，过去清单中被忽视或低估的地下废弃煤矿已成为 CMM 排放的第二大来源。从 2011 年到 2022 年，我们确定了山西、贵州和陕西是三个最大的 CMM 排放省份，而全球大气研究排放数据库（EDGAR）v8 高估了内蒙古的排放量，将其排名第三。值得注意的是，我们观察到 2011 年至 2022 年间，四川、河南、辽宁和湖南的 CMM 排放量大幅减少（超过 1 Mt），而 EDGAR v8 并未捕捉到这一点。为了在省级层面制定有针对性的 CMM 减排策略，我们根据 CMM 排放结构将 31 个省份分为四类。2022 年，CMM 排放主要来自废弃煤矿的省份数量已经超过了主要来自地下矿山的省份数量，这需要引起关注。本研究揭示了中国 CMM 排放源的特征，并为四组省份提供了减排方向。
