Bioenergy from energy crops is a source of negative emissions and carbon-neutral fuels in many 1.5/2 ^∘C IPCC pathways. This may compete with other land uses. In contrast, ancillary biomass like by-products and waste is not primarily grown for energy and thus without land/food/feed competition. Here, we examine the availability and environmental impacts of ancillary bioenergy from agricultural sources under 190 circular agroecological strategies using the global food-system model SOLm for the year 2050. We find that there is a diverse option space for the future food and energy system to meet both global warming targets (1.5 ^∘C) and food system sustainability (medium to highly organic) – a similar range of ancillary bioenergy global potential (55–65 EJ)from very different food systems (50%–75% organic agriculture and various levels of waste and concentrate feeding reduction). We find three trade-offs between food system sustainability and ancillary bioenergy provision. First, there is a clear trade-off between nutrient recycling and negative emissions potential. 1.4–2.6 GTCO₂eq of negative emissions supplied through ancillary bioenergy with carbon capture and storage comes at the cost of nutrient deficits and resulting incompatibility with even a medium degree of organic farming. Second, reducing feed from croplands increases the ancillary bioenergy production with low shares of organic agriculture and reduces it for high shares. Third, food waste reduction reduces ancillary bioenergy provision. Hence, the sustainable transformation of the food system towards a less animal-based diet and waste reduction may conflict with a higher ancillary bioenergy provision, especially when the organic share is high as well. The policy implication of our results is that ancillary bioenergy can provide a similar range of future bioenergy as foreseen in IPCC AR6 illustrative pathways (±10% ) without additional land use or compromising food availability. However, higher ancillary bioenergy provision or additional negative emissions compete with food system sustainability; hence, we recommend policymakers consider aligning energy system planning with the compatibility of sustainable food systems simultaneously.

中文翻译：

---

来自循环农业生态学的无土地生物能源——多样化的选择空间和权衡

^{来自能源作物的生物能源是许多 1.5/2 ∘} C IPCC 路径中负排放和碳中性燃料的来源 。这可能会与其他土地用途竞争。相比之下，副产品和废物等辅助生物质的种植主要不是为了能源，因此没有土地/食物/饲料竞争。在这里，我们使用 2050 年全球粮食系统模型 SOLm，研究了 190 种循环农业生态战略下农业来源辅助生物能源的可用性和环境影响。我们发现，未来的粮食和能源系统有多样化的选择空间满足全球变暖目标 (1.5  ^∘ C) 和粮食系统可持续性（中度到高度有机）——来自非常不同的粮食系统（50%–75% 有机农业和各种废物水平和浓缩饲料减少）。我们发现粮食系统可持续性和辅助生物能源供应之间存在三种权衡。首先，养分回收和负排放潜力之间存在明显的权衡。通过碳捕获和储存的辅助生物能源提供的1.4–2.6 GTCO ₂当量的负排放是以营养​​不足为代价的，并导致与中等程度的有机农业不相容。其次，减少农田饲料会增加有机农业比例较低的辅助生物能源生产，并减少比例较高的辅助生物能源生产。第三，减少食物浪费减少了辅助生物能源的供应。因此，粮食系统向减少动物性饮食和减少废物的可持续转变可能与更高的辅助生物能源供应相冲突，特别是当有机份额也很高时。我们的结果的政策含义是，辅助生物能源可以提供与 IPCC AR6 说明性路径 (±10%) 中预见的类似范围的未来生物能源，而无需额外的土地使用或损害粮食供应。然而，更高的辅助生物能源供应或额外的负排放与粮食系统的可持续性相竞争；因此，我们建议政策制定者考虑同时调整能源系统规划与可持续粮食系统的兼容性。