The Availability of Limestone and Other Raw Materials for Ocean Alkalinity Enhancement

The work assesses the availability and localizations of different raw materials suitable for ocean alkalinity enhancement (OAE), like limestone, olivine, magnesite brucite, since several billion tons rocky are needed to achieve meaningful results carbon sequestration through OAE. Resources carbonates immense widespread around all continents. Availability pure is still very large (outcrop area 4.1 million km2) not a constraint large-scale development Outcrops within 10 km from coastline below bare ground or scrub/shrub, preferred logistics exploitation, account about 70,000 km2, could provide 5,000 Gt limestone. These values increase by factor 3 8 50 100 coastline, respectively. Potential resources less easily identifiable geological data, estimated in order few hundred only minor contribution ocean-based removal strategies. A comparison with current level world extraction mineral also provided. annual production be more than 6.6 deposits scattered world, 9% (around 44 yr−1), same magnitude as coal (7.3 yr−1). productions (29 Mt olivine (8.4 yr−1) brucite (1.5 two orders lower.