Bioenergy with carbon capture and storage (BECCS) is crucial in many stringent climate scenarios. Although irrigation can enhance BECCS potential, where and to what extent it can enhance global BECCS potential are unknown when constrained by preventing additional water stress and suppressing withdrawal of nonrenewable water resources. With a spatially explicit representation of bioenergy crop plantations and water cycle in an internally consistent model framework, we identified the irrigable bioenergy cropland on the basis of the water resources reserve. Irrigation of such cropland enhanced BECCS potential by only 5–6% (<60–71% for unconstrained irrigation) above the rain-fed potential (0.82–1.99 Gt C yr⁻¹) by the end of this century. Nonetheless, it limited additional water withdrawal (166–298 km³ yr⁻¹), especially from nonrenewable water sources (16–20%), compared with unconstrained irrigation (1,392–3,929 km³ yr⁻¹ and 73–78%). Our findings highlight the importance of irrigation constraints in global BECCS potential.

具有碳捕获和储存功能的生物能源 (BECCS) 在许多严格的气候情景中至关重要。尽管灌溉可以提高 BECCS 的潜力，但当受到防止额外的水资源压力和抑制不可再生水资源的抽取的限制时，它可以在何处以及在多大程度上提高全球 BECCS 的潜力尚不清楚。通过在内部一致的模型框架中对生物能源作物种植园和水循环的空间明确表示，我们根据水资源储备确定了可灌溉的生物能源农田。到本世纪末，这种农田的灌溉使 BECCS 潜力仅比雨养潜力（0.82-1.99 Gt C yr ^-1）高5-6%（无约束灌溉<60-71%）。尽管如此，它限制了额外的取水（166-298 公里³  yr ^-1），尤其是来自不可再生水源（16-20%），与无约束灌溉（1,392-3,929 km ³  yr ^-1和 73-78%）相比。我们的研究结果强调了灌溉限制在全球 BECCS 潜力中的重要性。