The Key Role of Production Efficiency Changes in Livestock Methane Emission Mitigation

Abstract

The livestock sector is the largest source of anthropogenic methane emissions and is projected to increase in the future with the increased demand for livestock products. Here, we compare livestock methane emissions and emission intensities, defined by the amount of methane emitted per unit of animal proteins, estimated by different methodologies, and identify mitigation potentials in different regions of the world based on possible future projections. We show that emission intensity decreased for most livestock categories globally during 2000–2018, due to an increasing protein‐production efficiency, and the IPCC Tier 2 method should be used for capturing the temporal changes in the emission intensities. We further show that efforts on the demand‐side to promote balanced, healthy, and environmentally sustainable diets in most countries will not be sufficient to mitigate livestock methane emissions without parallel efforts to improve production efficiency. The latter efforts have much greater mitigating effects than demand‐side efforts, and hence should be prioritized in a few developing countries that contribute most of the mitigation potential.Livestock production represents a third of the global anthropogenic methane emissions nowadays, and the emissions are expected to keep increasing in the future. Using three sets of methodologies and emission factors from two versions of the IPCC guidelines (the 2006 and the 2019 refinement), we re‐assess global livestock methane emissions over the past two decades and project the emissions till 2050. We find a decreasing trend of methane emission intensity per kg of protein produced during the past two decades. We show that promoting balanced, healthy, and environmentally sustainable diets in most countries can mitigate future livestock methane emissions, but a larger mitigation potential is projected if the past trend in decreasing emission intensity (i.e., increasing production efficiency) can be continued. We further identify major countries that have the largest mitigation potential through increasing production efficiency. Emission intensity decreased for most livestock categories globally during 2000–2018, with an increasing protein‐production efficiency The continuation of the past decreases in emission intensity provides a large potential to mitigate livestock emissions Improving production efficiency has a much greater mitigating effect than demand‐side efforts, and should be prioritized in a few countries