Pipe Dreams: Evaluation of Ocean CO2 Injection as a Means for Reducing Atmospheric Carbon Dioxide Concentrations

Deep ocean injection of carbon dioxide (CO2) has been proposed as one means of dealing with the build-up of anthropogenic CO2 in the atmosphere. This study used a series of Earth System Model experiments to inject an idealized pulse of CO2 into each ocean grid cell to assess the efficiency of each location in storing CO2 over a 1,000 year period relative to how that CO2 would enter the ocean naturally. Potential injection sites were selected based on a series of criteria, including physical constraints, technological capability for access, and socio-environmental importance to society. After these restrictions were applied, 19 sites were identified, possessing relative efficiencies between 60 to 100% by year 200 and –7 to 9% by year 1,000. Carbon sequestration costs for the 19 eligible injection sites range from US$75.55 to US$1054.75/ton CO2 net stored, which is not competitive with other carbon sequestration options at this time.