1970—2018年中国甲烷排放量时空分布特征及行业排放源分析

在100年时间尺度上,甲烷(CH₄)气体的全球增温潜势是CO₂的25倍,研究CH₄排放的时空特征及排放源组成结构对于国家"双碳目标"的实现具有重要价值.本文基于全球大气研究排放数据库(EDGAR)中的数据集,刻画了中国CH₄排放的时空分布特征,利用空间自相关和热点分析方法,揭示了CH₄排放的空间集聚效应,并基于不同的行业部门排放数据对CH₄的排放源进行分析.研究表明:1970—2018年CH₄排放的热点区主要分布在我国的华东、华北以及华南地区,有逐渐向西北地区延伸的趋势;年CH₄排放量平均值达8.33 t·a^-1·km^-2,变化曲线总体上呈现平缓上升—急速上升—稳定排放三个阶段;从各行政区的排放量来看,上海一直处于最高,全市排放量十年间平均值不低于25 t·km^-2;能源活动和工业生产的CH₄排放量贡献突出,尤其是交通运输和煤炭开采近些年排放占比逐渐攀升.

Spatiotemporal dynamics and source analysis of China's methane emissions from 1970 to 2018

On a 100-year time scale,the global warming potential of methane (CH₄) is 25 times that of CO₂.Revealing the spatiotemporal dynamics of CH₄ emissions and the composition of emission sources is of great value for the realization of the national dual-carbon goal.Based on the data set in the Emissions Database for Global Atmospheric Research (EDGAR),this paper characterizes the spatiotemporal distribution characteristics of CH₄ emissions in China,and uses spatial autocorrelation and hotspot analysis methods to reveal the spatial agglomeration effect of CH₄ emissions.The data were analyzed for CH₄ emission sources.The results show that the hotspots of CH₄ emissions from 1970 to 2018 mainly distributed in East China,North China and South China,and had a trend of gradually extending to the northwest region.In general,there were three stages from gradual rise to rapid rise and then stable emission;from the perspective of emissions in each administrative region,Shanghai has always been at the highest level,with average emission in ten years being not less than 25 t·km^-2;energy activities and industrial production contributed most to CH₄,especially the transportation and coal mining sectors which held gradually increasing proportions of emissions in recent years.The research results can provide effective guidance for exploring industry emission reduction plans and practicing low-carbon paths.