Campbell et al. (2026): Harnessing naturally occurring sodium carbonate and bicarbonate for gigatonne-scale carbon dioxide removal
James Campbell, Spyros Foteinis, Reinaldo Juan Lee Pereira, Mohamad Katish and Phil Renforth, IN: EarthArXiv, https://doi.org/10.31223/X5276Q
Ocean alkalinity enhancement is a promising carbon dioxide removal (CDR) approach, but scaling up to gigatonnes (Gt) of CO₂ per year will require safe, sustainable, and abundant alkaline feedstocks. Here, the authors propose the use of a relatively unexplored resource for OAE, namely naturally occurring sodium (bi)carbonates. The authors identified and mapped 109 such deposits globally, although quantitative resource information is available for only 16. Quantified deposits collectively contain >200 Gt of sodium (bi)carbonate-rich minerals and brines, dominated by trona (Na₂CO₃·NaHCO₃·2H₂O) and nahcolite (NaHCO₃) mainly concentrated in the USA, China, Turkey, and Kenya.