中国农业源非CO_(2)温室气体排放核算

Calculation of non-CO_(2)greenhouse gas emissions from Chinese agricultural sources

中国作为传统的农业大国,高消耗、高投入、高需求的农业发展模式推动着中国农业非CO_(2)温室气体排放总量持续增长。农业源非CO_(2)气体以极具增温潜势的CH_(4)和N2O为主,控制农业源非CO_(2)温室气体排放是我国实现农业绿色发展和“双碳”目标的重要环节。我国农业系统非CO_(2)温室气体核算尚处于不断探索完善的过程之中,在估算方法、模型参数等方面还未形成一套完整和公认的体系。研究参考IPCC分类法建立了适用于中国农业系统的,包括种植业、畜牧业和农业废弃物的农业非CO_(2)温室气体排放核算体系。以2020年为基准对中国农业温室气体排放情况进行了核算。结果显示,我国农业系统非CO_(2)温室气体排放总量为62801.68万t CO_(2)-e,CH_(4)是农业系统排放贡献最大的温室气体。我国农业系统温室气体排放类型具有明显的空间分异特征;西北、华北、西南以畜牧业温室气体为主导,华东、华南地区以种植业为主导,东北、华中地区较为特殊,主导类型相对复杂;农业废弃物排放主要分布在东北、华东地区。研究所构建的温室气体核算体系可充分体现我国农业温室气体排放现状,体现各省域农业温室气体排放结构,有利于各区域制定有针对性的农业规划政策,可为降低我国农业温室气体核算研究中的不确定性、为碳中和实现过程中明确农业系统的温室气体贡献提供方法支持与数据基础。

As a traditional agricultural powerhouse,China′s agricultural development model characterized by high consumption,high input,and high demand continues to drive the continuous increase in China′s total non-CO_(2)greenhouse gas emissions from agriculture.Non-CO_(2)gases from agricultural sources,predominantly CH_(4)and N2 O with high warming potential,are the main contributors.Controlling non-CO_(2)greenhouse gas emissions from agricultural sources is a crucial aspect for China to achieve agricultural green development and its“dual-carbon”goals.The accounting of non-CO_(2)greenhouse gases in China′s agricultural system is still in a process of continuous exploration and improvement,with no complete and universally recognized system established yet in terms of estimation methods and model parameters.This study,referencing the IPCC classification method,established an accounting system for non-CO_(2)greenhouse gas emissions from agriculture tailored to the characteristics of China′s agricultural system,including crop cultivation,animal husbandry,and agricultural waste,and conducted an assessment of China′s agricultural greenhouse gas emissions in 2020 as the baseline.The results showed that the total non-CO_(2)greenhouse gas emissions from China′s agricultural system amounted to 62801.68 ten thousand tons of CO_(2)-e,with CH_(4)being the largest contributor,accounting for 71%of the total emissions.In terms of individual emission categories,emissions from livestock farming reached 33,205.34 ten thousand tons of CO_(2)-e,exceeding 50%of the total emissions,followed by emissions from crop production at 28,617.93 ten thousand tons of CO_(2)-e;agricultural waste emissions were relatively low,at only 978.42 ten thousand tons of CO_(2)-e.The types of greenhouse gas emissions from China′s agricultural system exhibited obvious spatial differentiation characteristics;emissions from livestock farming dominated in the northwest,north China,and southwest,while emissions from crop production dominated in east China and south China.The northeast and central China regions were relatively special,with a mixture of emissions from livestock farming and crop production,as well as dual dominance of emissions from crop cultivation and animal husbandry.Agricultural waste emissions were mainly concentrated in the northeast and east China regions,where crop production was relatively developed.The greenhouse gas accounting constructed in this study fully reflects the current status of China′s agricultural greenhouse gas emissions and the emission structure of agricultural greenhouse gases in each province,which is conducive to the formulation of targeted agricultural planning policies in various regions.It also provides methodological support and data basis for reducing uncertainties in Chinese agricultural greenhouse gas accounting research and clarifying the contribution of the agricultural system to carbon neutrality.