Document Type


Publication Date



This paper explores two ocean-based carbon dioxide removal strategies – ocean alkalinity enhancement and seaweed cultivation. Ocean alkalinity enhancement involves adding alkalinity to ocean waters, either by discharging alkaline rocks or through an electrochemical process, which increases ocean pH levels and thereby enables greater uptake of carbon dioxide, as well as reducing the adverse impacts of ocean acidification. Seaweed cultivation involves the growing of kelp and other macroalgae to store carbon in biomass, which can then either be used to replace more greenhouse gas-intensive products or sequestered.

This paper also examines the international and U.S. legal frameworks that apply to ocean alkalinity enhancement and seaweed cultivation. Depending on where they occur, such activities may be subject to international, national, state, and/or local jurisdiction. Under international law, countries typically have jurisdiction over activities within 200 nautical miles of their coastline. In the U.S., coastal states typically have primary authority over areas within three nautical miles of the coast, and the federal government controls U.S. waters further offshore.


Environmental Law | International Law | Law | Law of the Sea


Sabin Center for Climate Change Law