Power et al. (2024): Are enhanced rock weathering rates overestimated? A few geochemical and mineralogical pitfalls
Ian M. Power, Victoria N.J. Hatten, Minger Guo, Zivi Schaffer, Kwon Rausis, Heather Klyn-Hesselink IN: Frontiers in Climate, doi: 10.3389/fclim.2024.1510747
Here, the authors aim to contribute to the discussion of CDR quantification by describing three potential pitfalls relating to the geochemical and mineralogical composition of rock powders. First, rock powders used for ERW are often mineralogically complex and may initially exhibit fast dissolution rates due to reactive surfaces and phases, leading to overestimating long-term CDR rates. Second, the dissolution of accessory carbonates within ERW rock powders will tend to dominate cation and dissolved inorganic carbon fluxes, which, if not identified, can be misconstrued as silicate weathering and overestimate CDR. Third, methods that rely on measuring cations may be prone to misinterpretation as cations will often not be balanced with dissolved inorganic carbon, e.g., during strong acid weathering.