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Carbon dioxide removal (“CDR”) will be needed, alongside deep emissions cuts, to achieve global temperature goals. According to a 2022 report by the Intergovernmental Panel on Climate Change, to keep global average temperatures within 1.5°C above preindustrial levels, carbon dioxide and other greenhouse gas emissions must reach net-zero by mid-century. Scientists have proposed a number of land- and ocean-based CDR techniques. This paper focuses on ocean fertilization, which involves adding iron or other nutrients to the ocean to stimulate the growth of phytoplankton that uptake carbon dioxide and convert it into organic carbon. The hope is that the organic carbon will end up sequestered in the deep ocean when the phytoplankton die and sink.

Scientists have conducted a number of in-ocean fertilization experiments, which suggest that adding iron does stimulate phytoplankton blooms, leading to increased uptake of carbon dioxide. However, further study is needed to evaluate whether ocean fertilization leads to long-term carbon storage and evaluate its potential co-benefits and risks, including the potential for nutrient-diversion from other ocean areas.

This paper explores the application of existing international and domestic (U.S.) law to ocean fertilization research and deployment. There are currently no legally binding international treaties dealing specifically with ocean fertilization. However, in recent years, three international treaty bodies have taken initial steps to develop rules for ocean fertilization research and deployment. At the domestic level, the Marine Protection, Research, and Sanctuaries Act (“MPRSA”) regulates the discharge of material into ocean waters within twelve nautical miles of the U.S. coast and further offshore in some cases. Ocean fertilization projects are likely to require a permit from the U.S. Environmental Protection Agency under the MPRSA. Additional permitting and other legal requirements could apply to the mining and processing of iron and other materials for use in ocean fertilization.


Environmental Law | Law


Sabin Center for Climate Change Law