Field experiments in ocean alkalinity enhancement research

Abstract

This chapter focuses on considerations for conducting open-system field experiments in the context of ocean alkalinity enhancement (OAE) research. By conducting experiments in real-world marine and coastal systems, researchers can gain valuable insights into ecological dynamics; biogeochemical cycles; and the safety, efficacy, and scalability of OAE techniques under natural conditions. However, logistical constraints and complex natural dynamics pose challenges. To date, only a limited number of OAE field studies have been conducted, and guidelines for such experiments are still evolving. Due to the fast pace of carbon dioxide removal (CDR) research and development, we advocate for openly sharing data, knowledge, and lessons learned as quickly and efficiently as possible within the broader OAE community and beyond. Considering the potential ecological and societal consequences of field experiments, active engagement with the public and other stakeholders is desirable, while collaboration, data sharing, and transdisciplinary scientific teams can maximize the return on investment. The outcomes of early field experiments are likely to shape the future of OAE research, implementation, and public acceptance, emphasizing the need for transparent and open scientific practices.

Biological response of eelgrass epifauna, Taylor’s sea hare (Phyllaplysia taylori) and eelgrass isopod (Idotea resecata), to elevated ocean alkalinity

“…This work should be scaled up to understand the effects of alkalinity enhancement on an ecosystem level using mesocosm studies, allowing for a more realistic depiction of a natural ecosystem while still keeping the treatment confined and allow for both benthic and pelagic species or ecosystem studies (Riebesell et al 2023). Future research could leverage lessons learned from laboratory experiments and mesocosm studies to eventually scale up to small scale field studies in sites under consideration for enhanced alkalinity approaches (Cyronak et al 2023).…”

Review and syntheses: Ocean alkalinity enhancement and carbon dioxide removal through coastal enhanced silicate weathering with olivine

“…Furthermore, while small-scale experiments in benchtop reactors or microcosms are key to constraining specific parameters and attaining detailed process knowledge, they do not replicate the physical and biological transport and biogeochemical reactions within the natural seafloor. Therefore, a critical challenge for olivine-based CESW is the lack of information obtained from suitably large-scale experiments that are performed under in situ conditions, which is essential for assessing its real-world applicability (Cyronak et al, 2023;Meysman and Montserrat, 2017;Renforth and Henderson, 2017;Riebesell et al, 2023). Consequently, critical questions remain regarding the feasibility, efficiency, and ecosystem impacts of olivine-based CESW.…”

Guide to Best Practices in Ocean Alkalinity Enhancement Research

“…For this reason, the LCA should be specially tailored to OAE applications. Previous work on LCA best practices for similar sectors, such as those for direct air capture and storage (DACS) (Cooney, 2022), and for the wider CDR sector (Terlouw et al, 2021) can serve as a useful starting point.…”