The case against renewed ocean iron fertilization field trials
Year: 2026
Type: editorial
Abstract: Buesseler et al. call for larger and longer ocean iron fertilization (OIF) trials to assess climate-relevant carbon dioxide removal potential. We argue that such trials may document local ecosystem responses but cannot resolve the two central uncertainties for climate policy: removal potential and downstream consequences. Net atmospheric CO 2 removal depends on carbon export, air–sea re-equilibration, circulation, downstream nutrient redistribution, and ecosystem responses occurring beyond trial boundaries. Global models representing these processes consistently find removal potential to be low, and field trials cannot overturn that evidence. The same models identify delayed and far-field impacts on oxygen and ecosystems under basin-scale OIF, which trials can neither evaluate nor prevent, deferring judgment to the models they are intended to improve. Progressively larger OIF trials are therefore unwarranted. Research should instead prioritize observations of naturally fertilized systems and better models, which could test the controls on OIF carbon yield without deliberate perturbation.
Source: Dialogues on climate change.
Institutions: Sorbonne Université, University of Maine, University of Liverpool, Dalhousie University, Hebrew University of Jerusalem, Interuniversity Institute for Marine Sciences in Eilat, Rutgers, The State University of New Jersey, Centre National de la Recherche Scientifique, École Polytechnique, Université Paris Sciences et Lettres, École Normale Supérieure - PSL, Laboratoire de Météorologie Dynamique
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: hybrid
Estimated APC paid:
Funder: Agence Nationale de la Recherche
OpenAlex ID: W7224960970