Tasmanian Institute of Agriculture, University of Tasmania, Burnie, TAS, Australia.
Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, Vic., Australia.
Glob Chang Biol. 2021 Nov;27(22):5726-5761. doi: 10.1111/gcb.15816. Epub 2021 Aug 29.
Livestock have long been integral to food production systems, often not by choice but by need. While our knowledge of livestock greenhouse gas (GHG) emissions mitigation has evolved, the prevailing focus has been-somewhat myopically-on technology applications associated with mitigation. Here, we (1) examine the global distribution of livestock GHG emissions, (2) explore social, economic and environmental co-benefits and trade-offs associated with mitigation interventions and (3) critique approaches for quantifying GHG emissions. This review uncovered many insights. First, while GHG emissions from ruminant livestock are greatest in low- and middle-income countries (LMIC; globally, 66% of emissions are produced by Latin America and the Caribbean, East and southeast Asia and south Asia), the majority of mitigation strategies are designed for developed countries. This serious concern is heightened by the fact that 80% of growth in global meat production over the next decade will occur in LMIC. Second, few studies concurrently assess social, economic and environmental aspects of mitigation. Of the 54 interventions reviewed, only 16 had triple-bottom line benefit with medium-high mitigation potential. Third, while efforts designed to stimulate the adoption of strategies allowing both emissions reduction (ER) and carbon sequestration (CS) would achieve the greatest net emissions mitigation, CS measures have greater potential mitigation and co-benefits. The scientific community must shift attention away from the prevailing myopic lens on carbon, towards more holistic, systems-based, multi-metric approaches that carefully consider the raison d'être for livestock systems. Consequential life cycle assessments and systems-aligned 'socio-economic planetary boundaries' offer useful starting points that may uncover leverage points and cross-scale emergent properties. The derivation of harmonized, globally reconciled sustainability metrics requires iterative dialogue between stakeholders at all levels. Greater emphasis on the simultaneous characterization of multiple sustainability dimensions would help avoid situations where progress made in one area causes maladaptive outcomes in other areas.
家畜长期以来一直是粮食生产系统的组成部分,这往往不是出于选择,而是出于需要。虽然我们对家畜温室气体(GHG)排放缓解的认识已经发展,但主流关注点——在某种程度上是短视的——是与缓解相关的技术应用。在这里,我们(1)检查全球家畜温室气体排放的分布,(2)探索与缓解干预措施相关的社会、经济和环境共同效益和权衡,(3)评价量化温室气体排放的方法。这项审查揭示了许多见解。首先,虽然反刍家畜的温室气体排放在低收入和中等收入国家(LMIC;全球范围内,66%的排放来自拉丁美洲和加勒比、东亚和东南亚以及南亚)最大,但大多数缓解策略是为发达国家设计的。这一严重关切因以下事实而加剧:未来十年,全球肉类产量增长的 80%将发生在 LMIC。其次,很少有研究同时评估缓解的社会、经济和环境方面。在所审查的 54 项干预措施中,只有 16 项具有中高度缓解潜力的三重底线效益。第三,虽然旨在刺激采用既能减少排放(ER)又能固碳(CS)的策略的努力将实现最大的净排放缓解,但 CS 措施具有更大的缓解潜力和共同效益。科学界必须将注意力从对碳的普遍短视镜头转移到更全面、基于系统的、多指标方法上,这些方法要仔细考虑家畜系统存在的原因。有意义的生命周期评估和与系统一致的“社会经济行星边界”提供了有用的起点,这些起点可能会发现杠杆点和跨尺度涌现属性。协调一致的全球可持续性指标的制定需要各级利益相关者之间进行迭代对话。更加强调同时描述多个可持续性维度将有助于避免在一个领域取得的进展在其他领域造成适应性不良的结果。