Comparative assessment of United States coastal hubs for large scale electrochemical marine carbon dioxide removal

Removing carbon dioxide from the atmosphere is essential to meet climate targets and limit global warming. Oceans already absorb a large share of carbon dioxide, and electrochemical methods can strengthen this process by treating seawater to increase its storage capacity. Here, we identify locations along the United States coastline that can support large-scale deployment of such systems. Thirty-eight facilities with seawater intake, including power plants, desalination plants, and liquefied natural gas terminals, are grouped into five hubs: Northeast, Southeast, South, West, and Northwest. A decision-making framework evaluates each hub based on removal capacity, cost, energy mix, local emissions, community vulnerability, facility diversity, and supporting infrastructure. The South, West, and Northeast hubs rank highest for deployment because they combine strong removal potential, affordability, and infrastructure readiness. This framework provides a practical tool for selecting priority sites and guiding technology development and policy for ocean-based carbon dioxide removal. Assessment of 38 seawater-intake facilities along the continental United States coast reveals that large scale deployment of electrochemical marine-based carbon dioxide removal hubs is possible using a multicriteria decision-making framework.