Technologies for geological and carbonate-forming methods of CO2 mitigation are likely more mature than those of other chemical methods, and their costs and benefits are better known. Of the keywords searched, the largest number of documents discussed carbonation and mineralization (Figure ). References to carbonation are high but stabilize after 2011, while publications involving concrete for CO2 sequestration follow a different pattern. The total number of articles discussing CO2 sequestration and concrete is significantly smaller than the number of documents discussing carbonation (though some concrete articles may be included in documents discussing carbonation). The lower level of interest in CaCO3 than in other products of CO2 reduction may be evidence that in situ mineralization has more interest than ex situ mineralization. The number of publications discussing concrete for CO2 sequestration publications was quite low before increasing significantly in 2019.