There is growing interest in the scientific community and private sector in biological approaches to marine carbon dioxide removal\u2013strategies designed to enhance the ocean\u2019s natural ability to absorb carbon from the atmosphere. However, a study led by Megan Sullivan<\/a>, a postdoctoral researcher at GSO, suggests that some proposals may overlook an important factor.<\/p>\n\n\n\n \u201cMost conversations only focus on how much carbon sinks out of the surface ocean,\u201d said Sullivan. \u201cWe show that it\u2019s just as important to consider how nutrients cycle through the system. Understanding these differences will help scientists better predict how effective ocean-based climate interventions might be over decades or centuries.\u201d<\/p>\n\n\n\n One widely discussed carbon removal approach is ocean fertilization, particularly adding iron to certain regions of the ocean to stimulate phytoplankton growth. Like planting trees on land, the idea is that increased growth will pull more carbon dioxide from the atmosphere. This biologically captured carbon then sinks to the deep ocean, where it can remain stored for decades to centuries.<\/p>\n\n\n\n Sullivan and her colleagues developed a modeling framework to run large-scale ocean simulations on high-performance computing systems. Their model tracked how both carbon and phosphorus, a key nutrient required for phytoplankton growth, move through the ocean over time. Because carbon uptake is tightly linked to nutrient availability, the simulations helped the researchers understand how carbon and nutrient cycles interact.<\/p>\n\n\n\n They found that carbon and nutrients do not follow the same timeline. Biologically captured carbon may return to the surface ocean relatively quickly, while nutrients such as phosphorus remain trapped in the deep ocean for much longer. The findings suggest that some proposed marine carbon removal strategies, including iron fertilization, could overestimate their long-term impact if they focus only on carbon export without accounting for nutrient redistribution. As interest grows in ocean-based carbon removal projects, understanding these long-term nutrient feedbacks will be critical for accurately assessing climate benefits.<\/p>\n\n\n\n Sullivan\u2019s research, which began as part of her Ph.D. dissertation at the University of California, Irvine and has continued at URI as a postdoctoral fellow, was published in the journal PNAS<\/em><\/a> in February. At UC Irvine, Sullivan worked closely with her advisors, Fran\u00e7ois Primeau and Adam Martiny. At URI, Sullivan worked with Keisuke Inomura<\/a>, an assistant professor of oceanography, to further develop and refine her manuscript.<\/p>\n","protected":false},"excerpt":{"rendered":" URI researcher\u2019s findings inform strategies for removing atmospheric carbon dioxide<\/p>\n","protected":false},"author":4762,"featured_media":192208,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[79],"tags":[3052,2997],"class_list":["post-192207","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","tag-carbon-dioxide-removal","tag-keisuke-inomura"],"acf":[],"_links":{"self":[{"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/posts\/192207","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/users\/4762"}],"replies":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/comments?post=192207"}],"version-history":[{"count":2,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/posts\/192207\/revisions"}],"predecessor-version":[{"id":192210,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/posts\/192207\/revisions\/192210"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/media\/192208"}],"wp:attachment":[{"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/media?parent=192207"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/categories?post=192207"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/web.uri.edu\/gso\/wp-json\/wp\/v2\/tags?post=192207"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\u201cThis mismatch matters,\u201d Sullivan explained. \u201cIf nutrients like phosphorus are locked away in the deep ocean, phytoplankton growth is suppressed, reducing the ocean\u2019s ability to continue absorbing carbon dioxide.\u201d The team describes this as a potential \u201cproductivity hangover,\u201d where an initial boost in carbon uptake is followed by a longer-term slowdown. In other words, an intervention that appears successful in the short term may not deliver sustained climate benefits.<\/p>\n\n\n\n