Geochemical Drivers of Enhanced Rock Weathering in Soils

Experimental research indicates that the efficiency of enhanced rock weathering (ERW) as a form of carbon dioxide removal (CDR), is subject to large variations in effectivity, and that the current state of knowledge is not sufficient to develop robust predictive capabilities. It appears that the heterogeneous mineralogy and reactivity of basalt, as well as the regional and local pedoclimatic parameters, greatly influence its weathering characteristics, and in turn, its ability to sequester CO2. Therefore, ERW efficiency should not be taken for granted but should, rather, be pursued according to a careful rock and soil geochemical selection. If ERW is to eventually become a significant CDR technology, then future research programs must bring together the fields of geochemistry, engineering, life cycle analysis, biology, soil physics, hydrology, and agronomy, as well as social sciences such as economy, law, and sociology. Furthermore, it is vitally important that research constraints relating to CDR methodologies be lifted in the immediate future. Indeed, CDR funds need to be allocated based on solid science to insure their overall efficiency as well as the credibility of the scientific community in the long run.