Thomas J-B E, Xu V W, Krizsan S J, Aasen I M, Oliveira A, Ramos H, Tyedmers P, Hayes M, Gröndahl F
Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, 100 44, Stockholm, Sweden.
Department of Agricultural Sciences, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Campus Blæstad, 2322, Hamar, Norway.
Sci Rep. 2025 Sep 18;15(1):32597. doi: 10.1038/s41598-025-18322-1.
Livestock supply chains contribute a substantial share of global anthropogenic greenhouse gas (GHG) emissions, with enteric methane (CH₄) from ruminants being a key driver. Seaweed-derived feed additives have been proposed as a CH₄ mitigation strategy, but their broader environmental trade-offs remain unclear. This study applies life cycle assessment (LCA) to evaluate seven seaweed-supplemented scenarios across beef, dairy, and sheep production, assessing climate change, marine and freshwater eutrophication, land use, fossil fuel depletion, and water use. Results indicate that while certain seaweed additives can lower CH₄ emissions in vitro, real-world reductions in total GHG emissions remain modest. Energy-intensive processing and long transport distances can offset CH₄ abatement gains, with only scenarios utilizing low-impact by-products achieving net climate benefits. Sensitivity analyses highlight the importance of Global Warming Potential (GWP) time horizon selection, energy sources, and grazing practices in determining overall environmental performance. Optimizing algae sourcing, processing, and application will be essential to realizing meaningful and scalable mitigation potential in ruminant systems. While seaweed additives can contribute to CH₄ reduction, this study concludes they will not single-handedly deliver transformative climate benefits.
畜牧供应链在全球人为温室气体（GHG）排放中占很大比例，反刍动物产生的肠道甲烷（CH₄）是一个关键驱动因素。源自海藻的饲料添加剂已被提议作为一种减少甲烷排放的策略，但其更广泛的环境权衡仍不明确。本研究应用生命周期评估（LCA）来评估牛肉、奶牛和绵羊生产中七种添加海藻的情景，评估气候变化、海洋和淡水富营养化、土地利用、化石燃料消耗和水资源利用。结果表明，虽然某些海藻添加剂在体外可降低甲烷排放，但实际温室气体总排放量的减少仍然有限。能源密集型加工和长距离运输会抵消甲烷减排的成效，只有利用低影响副产品的情景才能实现净气候效益。敏感性分析突出了全球变暖潜能值（GWP）时间范围选择、能源来源和放牧方式在确定整体环境绩效方面的重要性。优化海藻的采购、加工和应用对于在反刍动物系统中实现有意义且可扩展的减排潜力至关重要。虽然海藻添加剂有助于减少甲烷排放，但本研究得出结论，它们不会单独带来变革性的气候效益。
