Raven et al. (2026): Ideas and perspectives: Max MACS – constraining the potential global scale of Marine Anoxic Carbon Storage for CO₂ removal

Morgan Reed Raven, Nitai Amiel, Dror L. Angel, James P. Barry, et al., IN: Biogeosciences, https://doi.org/10.5194/bg-23-3755-2026

Marine Anoxic Carbon Storage (MACS) is a potential strategy for enhancing atmospheric CO₂ removal (CDR) by sequestering organic carbon produced by terrestrial plants in stable, anoxic marine reservoirs. Initial results suggest that MACS could, in theory, operate at the gigatonne scale that would be required to impact global climate, with limited environmental risk and promising opportunities for co-benefits. However, several outstanding knowledge gaps make it challenging to quantify the actual potential global scale of MACS with confidence. To inform decisions about climate mitigation and trade-offs in the future, it is essential that the authors know how MACS implementation at scale would impact critical environmental and economic systems in the context of likely future scenarios. Building on the results of a workshop in Bucharest, Romania in 2025, the authors discuss the potential impacts of MACS activities on the ecology, biogeochemistry, economy, and community around the Black Sea, seafloor brines, and other anoxic marine sites.

⁠LINK

⁠LINK