The relationship between livestock production and climate change is the subject of hot debate, with arguments for major shifts in diets and a reduction in livestock production. This Perspective examines how global assessments of livestock-derived methane emissions are framed, identifying assumptions and data gaps that influence standard life-cycle analysis approaches. These include inadequate data due to a focus on industrial not extensive systems; errors arising due to inappropriate emission factors being applied; questions of how global warming potentials are derived for different greenhouse gases and debates about what baselines are appropriate. The article argues for a holistic systems approach that takes account of diverse livestock systems—both intensive and extensive—including both positive and negative impacts. In particular, the potential benefits of extensive livestock systems are highlighted, including supporting livelihoods, providing high-quality nutrition, enhancing biodiversity, protecting landscapes, and sequestering carbon. By failing to differentiate between livestock systems, global assessments may mislead. Inappropriate measurement, verification and reporting processes linked to global climate change policy may in turn result in interventions that can undermine the livelihoods of extensive livestock-keepers in marginal areas, including mobile pastoralists. In the politics of global assessments, certain interests promote framings of the livestock-climate challenge in favour of contained, intensive systems, and the conversion of extensive rangelands into conservation investments. Emerging from a narrow, aggregated scientific framing, global assessments therefore can have political consequences. A more disaggregated, nuanced approach is required if the future of food and climate change is to be effectively addressed.

中文翻译：

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牲畜、甲烷和气候变化：全球评估的政治

畜牧业生产与气候变化之间的关系是热门争论的主题，人们认为饮食结构将发生重大变化，畜牧业产量也会减少。本视角研究了如何构建对牲畜产生的甲烷排放的全球评估，确定影响标准生命周期分析方法的假设和数据差距。其中包括由于关注工业而不是广泛的系统而导致数据不足；由于应用不适当的排放因子而产生的误差；关于如何得出不同温室气体的全球变暖潜势的问题以及关于什么基线合适的争论。本文主张采用整体系统方法，考虑不同的畜牧系统（集约型和粗放型），包括积极和消极影响。特别强调了粗放畜牧系统的潜在好处，包括支持生计、提供高质量营养、增强生物多样性、保护景观和固碳。由于无法区分畜牧系统，全球评估可能会产生误导。与全球气候变化政策相关的不适当的测量、核查和报告流程可能反过来导致干预措施损害边缘地区广大牲畜饲养者（包括流动牧民）的生计。在全球评估的政治中，某些利益集团推动牲畜气候挑战的框架有利于封闭的集约系统，以及将广阔的牧场转变为保护投资。因此，来自狭隘、综合的科学框架的全球评估可能会产生政治后果。如果要有效解决粮食和气候变化的未来问题，就需要采取更加分类、细致的方法。