Tagliabue A. auteur aut IRD Twining B. S. auteur aut IRD Barrier Nicolas auteur aut IRD Maury Olivier auteur aut IRD Berger M. auteur aut IRD Bopp L. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Climate change scenarios suggest that large-scale carbon dioxide removal (CDR) will be required to maintain global warming below 2 degrees C, leading to renewed attention on ocean iron fertilization (OIF). Previous OIF modelling has found that while carbon export increases, nutrient transport to lower latitude ecosystems declines, resulting in a modest impact on atmospheric CO2. However, the interaction of these CDR responses with ongoing climate change is unknown. Here, we combine global ocean biogeochemistry and ecosystem models to show that, while stimulating carbon sequestration, OIF may amplify climate-induced declines in tropical ocean productivity and ecosystem biomass under a high-emission scenario, with very limited potential atmospheric CO2 drawdown. The 'biogeochemical fingerprint' of climate change, that leads to depletion of upper ocean major nutrients due to upper ocean stratification, is reinforced by OIF due to greater major nutrient consumption. Our simulations show that reductions in upper trophic level animal biomass in tropical regions due to climate change would be exacerbated by OIF within similar to 20 years, especially in coastal exclusive economic zones (EEZs), with potential implications for fisheries that underpin the livelihoods and economies of coastal communities. Any fertilization-based CDR should therefore consider its interaction with ongoing climate-driven changes and the ensuing ecosystem impacts in national EEZs. specialized biogeochemical cycles climate change marine carbon dioxide removal marine ecosystems ocean iron fertilization ocean net primary production 036 082 021 [Early access] [11 ] 2023 1354-1013 https://www.documentation.ird.fr/hor/fdi:010088296 10.1111/gcb.16854 1354-1013 [F B010088296] https://www.documentation.ird.fr/hor/fdi:010088296 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2023-09/010088296.pdf IRD - Base Horizon / Pleins textes 2023-09-22 2025-02-24 fdi:010088296 fre