Marine carbon dioxide removal (mcdr) has the potential to contribute to climate change mitigation; however, the rate at which the mcdr industry must scale to enable meaningful removals presents…

Marine carbon dioxide removal (mcdr) has the potential to contribute to climate change mitigation; however, the rate at which the mcdr industry must scale to enable meaningful removals presents substantial challenges. The next decade will be pivotal; IT is now critical to establish pilot projects that demonstrate proof-of-concept and provide a basis for scaling. This project will conduct an ocean alkalinity enhancement (OAE) pilot project in partnership with a local municipal utility, leveraging an existing wastewater treatment plant outfall in SAN francisco BAY. The investigators will use a numerical modeling framework to design this experiment, including the release strategy and a sampling plan that enables tracking effects in the environment. They will release two additional tracers (3HE and SF6) in concert with alkalinity, thus enabling tracking of the perturbed water mass and determination of the gas exchange velocity, which is an important, yet uncertain, factor determining CO2 uptake rates in coastal environments. This project will be instrumental in demonstrating the viability and challenges associated with using wastewater outfall locations as an approach to OAE. Following the experiment, the team will conduct a retrospective analysis that combines models and observations to estimate the efficacy of the OAE release in drawing down additional atmospheric CO2.further, they will apply the modeling framework to produce CDR efficacy estimates for OAE applied at this site via a probabilistic approach that characterizes median uptake and the associated uncertainty for particular release scenarios. The technical work will be accompanied by a public engagement component, designed to introduce local groups (e.g., communities, tribes, ngos, civil society organizations) to the project; IT will explore how the project aligns with their views and priorities, and what associated risks and CO-benefits these groups perceive. All activities on this project, including hiring, internal operations, and external communication, will be conducted in accordance with a commitment to diversity, equity, and inclusion. Key deliverables of this project will be an evaluation of OAE efficacy in a specific coastal ocean system, a demonstration of measurement, reporting, and verification (MRV) for OAE applied to coastal outfalls, and a set of recommendations on methods and best practices for conducting public engagement alongside future pilot field trials of OAE and related mcdr approaches.