The scalability and carbon removal potential of ocean alkalinity enhancement

Most studies on economy-wide deep decarbonization find the need for widespread deployment of carbon dioxide removal (CDR) yet almost none of those studies pay much attention to real-world scalability of such novel technologies. We assess the scalability of ocean alkalinity enhancement (OAE), a promising CDR approach, and find a global removal potential of 0.64–2.7 Gt CO ₂ yr ^-1 by 2100. Most of that growth occurs late in the century. The scalability of the industry beyond mid-century depends heavily on early investment; key policy interventions, today, would include direct support for early projects that can help get the industry going. Looking to the geography of scaling, we find a tension between deployment strategies restricted only to a small number of countries highly motivated to pay the cost of this technology and the value, soon, of global deployment and scaling.