One of the earliest proposed carbon-removal techniques is large-scale ocean fertilization. This is accomplished by adding iron or other
Iron fertilization of the oceans may be a strategy for removing CO2 from the atmosphere. The idea is that it stimulates the growth of phytoplankton and
#### Reference Manager Citation. With the controversy surrounding the most recent scientific iron fertilization experiment in the Southern Ocean (LOHAFEX) and the ongoing discussion about restrictions on large-scale iron fertilization activities by the London Convention, the debate about the potential use of iron fertilization for geoengineering has never been more public or more pronounced. To help inform this debate, we present a synoptic view of the two-decade history of iron fertilization, from scientific experiments to commercial enterprises designed to trade credits for ocean fertilization on a developing carbon market. We suggest that it is time to break this two-decade cycle, and argue that we know enough about ocean fertilization to say that it should not be considered further as a means to mitigate climate change. But, ocean fertilization research should not be halted: if used appropriately and applied to testable hypotheses, it is a powerful research tool for understanding the responses of ocean ecosystems in the context of climate change.
Further reading ETC’s Case Study, Ocean Fertilization near Haida Gwaii, http://www.etcgroup.org/content/case-study-ocean-fertilization-near-haida-gwaii Greenpeace, A scientifc critique of oceanic iron fertilization as a climate change mitigation strategy http://www.greenpeace.to/publications/iron_fe rtilisation_critique.pdf CBD, Scientifc Synthesis of the Impacts of Ocean Fertilization on Marine Biodiversity https://www.cbd.int/doc/publications/cbd-ts-45-en.pdf Strong, A. (2009) Ocean fertilization: Science, Policy, and Commerce, in:Oceanography, Vol. 22(3): 236 - 261, https://tos.org/oceanography/article/ocean-fertilization-science-policy-and-commerce; Secretariat of the CBD (2009) Scientifc Synthesis of the Impacts of Ocean Fertilization on Marine Biodiversity, Montreal, Technical Series No. 45, https://www.cbd.int/doc/publications/cbd-ts-45-en.pdf; Abate and Greenlee (2010); GESAMP (2019) High level review of a wide range of proposed marine geoengineering techniques, (Boyd, P.W. and Vivian, C.M.G., eds.), IMO/FAO/UNESCO-IOC/UNIDO/WMO/IAEA/UN/UN Environment/ UNDP/ISA Joint Group of Experts on the Scientifc Aspects of Marine Environmental Protection).
Here we review the state of knowledge on large-scale ocean fertilization by adding iron or other nutrients, either from external sources or via enhanced ocean
Ocean fertilization uses nutrients to enhance photosynthesis by marine phytoplankton, which remove CO₂ and convert it into biomass that can
Artificial upwelling is a geoengineering strategy that involves bringing relatively nutrient-rich waters from depth up to the surface ocean to stimulate
DEEP-OCEAN STEWARDSHIP INITIATIVE Fig. 1 Elements of the biological pump (Fig. 1 From McClain (2010) American Scientist) Deep Ocean Climate Intervention Impacts Deep Ocean Climate Intervention Impacts Ocean Fertilization Key Points DECEMBER 2021 Policy Brief Page 2 DOSI Scaling and Effectiveness The subarctic Northern Pacific, Eastern Equatorial Pacific and Southern Ocean are high-nutrient, low-chlorophyll regions where iron scarcity limits phytoplankton growth, and thus have been proposed for OIF (Yoon et al., 2018, GESAMP, 2019). The alteration of natural phytoplankton communities may result in changes in the seasonality of particulate organic carbon flux to the deep-sea floor (benthic-pelagic coupling) and in compositions of phytoplankton species in the marine snow, potentially impacting deep-sea benthic communities that rely on food from the ocean surface (Billet et al., 1983; Gooday, 1988; Graf, 1989; Ruhl and Smith, 2004; Nomaki et al., 2021).