Enteric methane emission factors of smallholder dairy farming systems across intensification gradients in the central highlands of Ethiopia

IF 3.9 3区环境科学与生态学 Q2 ENVIRONMENTAL SCIENCES

Carbon Balance and Management Pub Date : 2023-11-29 DOI:10.1186/s13021-023-00242-0

Abraham Abera Feyissa, Feyera Senbeta, Adugna Tolera, Dawit Diriba, Kalaya Boonyanuwat

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引用次数: 0

Abstract

Background

Following global pledges to reduce greenhouse gas (GHG) emissions by 30% by 2030 compared to the baseline level of 2020, improved quantification of GHG emissions from developing countries has become crucial. However, national GHG inventories in most Sub-Saharan African countries use default (Tier I) emission factors (EF_S) generated by the Intergovernmental Panel on Climate Change (IPCC) to estimate enteric CH₄ emissions from animal agriculture. The present study provides an improved enteric CH₄ emission estimate (Tier II) based on animal energy requirements derived from animal characteristics and performance data collected from about 2500 cattle in 480 households from three smallholder farming systems to represent the common dairy farming in the central highlands of Ethiopia. Using average seasonal feed digestibility data, we estimated daily methane production by class of animal and farming system and subsequently generated improved EF.

Results

Our findings revealed that the estimated average EF and emission intensities (EI) vary significantly across farming systems. The estimated value of EF for adult dairy cows was 73, 69, and 34 kg CH₄/cow/year for urban, peri-urban, and rural farming systems, respectively. Rural dairy farming had significantly higher emission intensity (EI) estimated at 1.78 CO₂-eq per kg of fat protein-corrected milk (FPCM) than peri-urban and urban 0.71 and 0.64 CO₂-eq kg⁻¹ FPCM dairy farming systems, respectively. The EF estimates in this study are lower than the IPCC's (2019) default value for both stall-fed high-productive and dual-purpose low-productive cows.

Conclusions

The current findings can be used as a baseline for the national emission inventory, which can be used to quantify the effects of future interventions, potentially improving the country's commitment to reducing GHG emissions. Similarly, this study suggests that increased animal productivity through improved feed has a considerable mitigation potential for reducing enteric methane emissions in smallholder dairy farming systems in the study area.

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埃塞俄比亚中部高地小农奶牛养殖系统跨集约化梯度的肠道甲烷排放因子

背景:在全球承诺到2030年将温室气体(GHG)排放量在2020年的基准水平上减少30%之后，改进发展中国家温室气体排放的量化变得至关重要。然而，大多数撒哈拉以南非洲国家的国家温室气体清单使用政府间气候变化专门委员会(IPCC)生成的默认(一级)排放因子(EFS)来估计畜牧业的肠道CH4排放量。本研究提供了一个改进的肠道甲烷排放估算(第二级)，该估算基于动物能量需求，这些能量需求来自来自埃塞俄比亚中部高地三个小农农业系统的约2500头牛的动物特征和性能数据，这些系统代表了埃塞俄比亚中部高地常见的奶牛养殖。利用平均季节性饲料消化率数据，我们按动物类别和耕作系统估计了每日甲烷产量，并随后产生了改善的饲料能量。结果:我们的研究结果表明，不同的农业系统估计的平均EF和排放强度(EI)差异显著。在城市、城郊和农村耕作系统中，成年奶牛的EF分别为73、69和34 kg CH4/奶牛/年。农村奶牛养殖的排放强度(EI)为1.78 co2当量/ kg，显著高于城市周边和城市的0.71和0.64 co2当量/ kg-1 FPCM奶牛养殖系统。本研究中对高产奶牛和双用途低产量奶牛的EF估计值均低于IPCC(2019)的默认值。结论:目前的研究结果可作为国家排放清单的基线，可用于量化未来干预措施的效果，从而有可能改善该国减少温室气体排放的承诺。同样，本研究表明，通过改善饲料提高动物生产力对于减少研究地区小农奶牛养殖系统的肠道甲烷排放具有相当大的缓解潜力。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Carbon Balance and Management Environmental Science-Management, Monitoring, Policy and Law

CiteScore

7.60

自引率

0.00%

发文量

审稿时长

14 weeks

期刊介绍： Carbon Balance and Management is an open access, peer-reviewed online journal that encompasses all aspects of research aimed at developing a comprehensive policy relevant to the understanding of the global carbon cycle. The global carbon cycle involves important couplings between climate, atmospheric CO2 and the terrestrial and oceanic biospheres. The current transformation of the carbon cycle due to changes in climate and atmospheric composition is widely recognized as potentially dangerous for the biosphere and for the well-being of humankind, and therefore monitoring, understanding and predicting the evolution of the carbon cycle in the context of the whole biosphere (both terrestrial and marine) is a challenge to the scientific community. This demands interdisciplinary research and new approaches for studying geographical and temporal distributions of carbon pools and fluxes, control and feedback mechanisms of the carbon-climate system, points of intervention and windows of opportunity for managing the carbon-climate-human system. Carbon Balance and Management is a medium for researchers in the field to convey the results of their research across disciplinary boundaries. Through this dissemination of research, the journal aims to support the work of the Intergovernmental Panel for Climate Change (IPCC) and to provide governmental and non-governmental organizations with instantaneous access to continually emerging knowledge, including paradigm shifts and consensual views.