A Novel Approach to Modeling the Regional Acidification Impacts of Ocean Carbon Disposal: Case Study of the U.S. East Coast

The seas are a powerful carbon sink. For this reason, taking advantage of the ocean’s natural ability to store carbon has been proposed as a global warming mitigation strategy. As anthropogenic emissions swell and ambitious climate goals set by the Paris Agreement become harder to achieve, carbon capture and storage is increasingly viewed as a potential silver bullet. However, the least expensive method of marine sequestration — direct injection of CO2 into the ocean — would carry unintended consequences, namely exacerbating already-occurring ocean acidification. The subsequent dispersal of CO2 particles would likely lower the pH of surrounding waters, impacting marine life and other resources that are economically significant to coastal communities. This paper presents a regional ocean acidification model (“ROAM”) that applies Lagrangian particle-tracking to examine the spatially varying impacts of offshore carbon sequestration (“OCS”) along the eastern coast of the United States. The model shows that disposal near strong circulation features like mesoscale eddies appears to allow CO2 to entrain and flow along unforeseen paths. Utilizing existing impact assessments of ocean acidification, ROAM then estimates the effect of OCS on commercial fisheries located in these areas. Based on cost-benefit analysis of these damages, neighboring coastal states display vastly different and often conflicting preferences for OCS, implying a need for coordination at the federal or global level. This research demonstrates that the cross-region externalities of OCS can be quantified and therefore internalized in the ongoing design of carbon capture regulations.