Beier Felicitas D, Dietrich Jan Philipp, Heinke Jens, Abrahao Gabriel, von Jeetze Patrick, Bodirsky Benjamin Leon, Crawford Michael, Humpenöder Florian, Merfort Leon, Weindl Isabelle, Herrero Mario, Mason-D'Croz Daniel, Rockström Johan, Sundiang Marina, Wierik Sofie Te, Norberg Anna, Klein David, Müller Christoph, Lotze-Campen Hermann, Popp Alexander
Potsdam Institute for Climate Impact Research, Member of the Leibniz Association, Potsdam, Germany; Humboldt-Universität zu Berlin, Albrecht Daniel Thaer-Institut für Agrar-und Gartenbauwissenschaften, Berlin, Germany.
Potsdam Institute for Climate Impact Research, Member of the Leibniz Association, Potsdam, Germany.
Lancet Planet Health. 2025 Jul 8. doi: 10.1016/S2542-5196(25)00087-7.
Ambitious climate change mitigation in all economic sectors is crucial for limiting global warming. Cost-effective mitigation pathways to keep global average temperature increases below 1·5°C by the end of the 21st century often rely on land-based greenhouse gas (GHG) emission reductions, increased land-based carbon uptake and biomass supply to other sectors (eg, energy and transport), and demand-side changes in the food system. To evaluate the broader sustainability of land-based climate change mitigation action, we evaluated synergies and trade-offs of individual and combined supply-side mitigation measures across five planetary boundaries. We also examined the role of a food demand transformation aligned with the dietary recommendations of the updated planetary health diet defined in the forthcoming EAT-Lancet Commission 2.0 report in shaping planetary boundary outcomes.
In this modelling study, we used the dynamic land-system modelling framework MAgPIE to assess the consequences of land-based GHG reductions, increased land-based carbon uptake, increased biomass supply to other sectors, and a food-system transformation towards the planetary health diet including food waste reductions on five planetary boundary domains (climate change, nitrogen, land-system change, freshwater use, and biosphere integrity) relative to a reference scenario without land-system mitigation throughout the century. For each planetary boundary control variable, we calculated the level of planetary boundary transgression (ie, the extent to which scenario outcomes exceeded the defined safe operating space) and assessed the contributions of land-based mitigation strategies to reducing planetary boundary transgressions projected for the reference scenario.
Our projections show that a food-system transformation together with ambitious land-system and energy-system climate change mitigation can limit global warming to below 1·5°C by 2100, while also reducing planetary boundary transgression (particularly for the climate change, land-system change, biosphere integrity, and nitrogen planetary boundaries). However, a safe operating space was not achieved through these mitigation measures, as most planetary boundaries were still projected to remain transgressed by the end of the 21st century. Increased bioenergy supply alone worsened planetary boundary transgression when only looking at land-system impacts, but combining increased bioenergy supply with GHG pricing in the land system alleviated these trade-offs. Food waste reductions and dietary shifts towards the planetary health diet were projected to ease pressures on the land system and reduce planetary boundary transgression of all assessed planetary boundaries.
This research highlights the importance of considering multiple planetary boundaries and the interactions between various mitigation strategies when assessing climate mitigation action in the land system to avoid negative consequences for other aspects of the environment. Following an ambitious climate change mitigation pathway compatible with the Paris Agreement results in a transgression of all assessed five planetary boundaries by 2100. However, the combination of the land-system mitigation measures included in this study produced a substantial shift towards the safe operating space for humanity.
EAT-Lancet Commission 2.0.
所有经济部门积极应对气候变化对于限制全球变暖至关重要。到21世纪末将全球平均气温升幅控制在1.5°C以下的具有成本效益的减缓途径通常依赖于陆地温室气体减排、增加陆地碳吸收以及向其他部门（如能源和交通）的生物质供应，以及食品系统的需求侧变化。为了评估陆地气候变化减缓行动更广泛的可持续性，我们评估了跨越五个地球边界的单项和综合供应侧减缓措施的协同效应和权衡取舍。我们还研究了与即将发布的《柳叶刀 - 饮食委员会2.0报告》中定义的更新后的地球健康饮食的饮食建议相一致的食品需求转变在塑造地球边界结果方面的作用。
在这项建模研究中，我们使用动态土地系统建模框架MAgPIE来评估陆地温室气体减排、增加陆地碳吸收、增加向其他部门的生物质供应以及向地球健康饮食的食品系统转变（包括减少食物浪费）相对于整个世纪无陆地系统减缓的参考情景对五个地球边界领域（气候变化、氮、土地系统变化、淡水使用和生物多样性完整性）的影响。对于每个地球边界控制变量，我们计算了地球边界越界水平（即情景结果超出定义的安全运行空间的程度），并评估了陆地减缓策略对减少参考情景中预计的地球边界越界的贡献。
我们的预测表明，食品系统转变以及积极的土地系统和能源系统气候变化减缓措施能够到2100年将全球变暖限制在1.5°C以下，同时也减少地球边界越界（特别是对于气候变化、土地系统变化、生物多样性完整性和氮地球边界）。然而，通过这些减缓措施并未实现安全运行空间，因为预计到21世纪末大多数地球边界仍将处于越界状态。仅增加生物能源供应在仅考虑土地系统影响时会加剧地球边界越界，但将增加生物能源供应与土地系统中的温室气体定价相结合可缓解这些权衡取舍。预计减少食物浪费以及向地球健康饮食的饮食转变将减轻对土地系统的压力并减少所有评估的地球边界的越界情况。
这项研究强调了在评估陆地系统中的气候减缓行动时考虑多个地球边界以及各种减缓策略之间相互作用的重要性，以避免对环境的其他方面产生负面影响。遵循与《巴黎协定》相符的积极气候变化减缓途径到2100年所有评估的五个地球边界都会出现越界。然而，本研究中包含的陆地系统减缓措施的组合使人类朝着安全运行空间有了实质性转变。
《柳叶刀 - 饮食委员会2.0》
