近日，美国加州大学欧文分校Adam C. Martiny团队报道了海洋铁施肥的气候效益和生态成本权衡。2026年7月29日出版的《自然》杂志发表了这项成果。

海洋铁施肥（OIF）正被作为一种潜在的二氧化碳移除（CDR）策略进行讨论。然而，气候效益与生态成本之间的权衡关系仍知之甚少。

研究组使用一个过程丰富的海洋生物地球化学模型，该模型具备经过验证的海洋生物多样性和生物地球化学表征，用以量化60年间十个海洋生物群落区的施肥潜力及生态系统影响。结果发现，气候–生态系统权衡存在区域差异：CDR效率相当的生物群落区，其生态结果却截然不同。南大洋和赤道太平洋通过不同途径实现了最高效率：前者通过非局域的下游碳输出，后者则通过局域输出但伴随下游损失，因为施肥引发的藻华消耗了源水中的大量营养盐，抑制了非局域生产力。因此，赤道施肥减少了向更高营养级的能量流动，扩大了最低含氧区（OMZs），并降低了大型浮游动物生物量。

这些生态系统影响可通过将部署地点转移至高纬度地区来避免。施肥后恢复实验表明，南大洋生态系统具有韧性，而赤道太平洋因区域性的铁滞留而呈现持续扰动。平衡气候效益与生态风险得出三个层级：南大洋（高效率/低风险）；赤道太平洋和全球施肥（高效率/高风险）；亚热带（低效率/中等风险）。60年的施肥产生净CDR为1.1–5.3 ppm，其中超过一半在施肥结束后的几十年内重新排放。局域干预与全球后果之间的脱节使可靠的碳信用核算变得复杂，并引发了公平性和治理方面的关切。

附：英文原文

Title: Climate benefit and ecological cost trade-offs for ocean iron fertilization

Author: Yu, Jun, Moore, J. Keith, Primeau, Francois W., Michaels, Anthony F., Nuno, Amy G., Krumhardt, Kristen M., Levy, Michael N., Lindsay, Keith, Wang, Hui, Randerson, James T., Martiny, Adam C.

Issue&Volume: 2026-07-29

Abstract: Ocean iron fertilization (OIF) is being discussed as a potential carbon dioxide removal (CDR) strategy1. Yet the trade-offs between climate benefits and ecological costs remain poorly understood2,3,4. Here we use a process-rich ocean biogeochemical model with validated representations of marine biodiversity and biogeochemistry5 to quantify fertilization potential and ecosystem impact across ten ocean biomes over 60years. We find regional disparities in climate ecosystem trade-offs: biomes with comparable CDR efficiency have contrasting ecological outcomes. The Southern Ocean and the equatorial Pacific achieve the highest efficiencies through distinct pathways: the former through non-local downstream carbon export, the latter through local export with downstream loss, as fertilized blooms deplete macronutrients in source water, suppressing non-local productivity. Consequently, equatorial fertilization reduces energy flows to higher trophic levels, expands oxygen-minimum zones (OMZs) and reduces macrozooplankton biomass. These ecosystem impacts are potentially avoidable by shifting deployment to higher latitudes. Post-fertilization recovery experiments reveal ecosystem resilience in the Southern Ocean but persistent perturbations in the equatorial Pacific owing to regional iron retention. Balancing climate benefits and ecological risks yields three tiers: the Southern Ocean (higher efficiency/lower risk); the equatorial Pacific and global fertilization (higher efficiency/higher risk); and the subtropics (lower efficiency/moderate risk). Sixtyyears of fertilization yield net CDR of 1.1–5.3ppm, with more than half re-emitted within decades post-fertilization. The disconnect between local interventions and global outcomes complicates robust carbon crediting and raises equity and governance concerns.

DOI: 10.1038/s41586-026-10795-y

Source: https://www.nature.com/articles/s41586-026-10795-y