Knapp & Tipper (2022): The efficacy of enhancing carbonate weathering for carbon dioxide sequestration

William J. Knapp and Edward T. Tipper IN: Frontiers in Climate, Sec. Negative Emission Technologies, https://doi.org/10.3389/fclim.2022.928215

Difference in calcite solubility between soils (where weathering occurs) and rivers (where HCO−3 is transported) may lead to large amounts of secondary carbonate formation during transport, releasing the CO₂ consumed through dissolution. Here, the authors present a modeling study comparing the estimated soil dissolution capacity (SDC) in 149 of Earth’s largest river basins, to the potential transport capacity of carbon (PTCC) in corresponding rivers. They find the SDC can only be exported to the oceans, without secondary carbonate precipitation, if rivers are in disequilibrium with respect to calcite (i.e., SIc = 1).

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