Here, k0 is the pre-exponential factor (1.29 × 107 mm3 mm− 2 yr− 1), Ea is the activation energy (70 kj mol− 1), and a is a spatial constant related to the scale of measurement of BET surface area (10− 7 mm). The term, , is the roughness. The roughness fractal dimension can be conceptualized as a factor related to both the thickness of the reaction front and the specific surface area within the reaction front. However, the above equation can also be written in terms of a surface fractal dimension and the hypothetical average grain radius. These fractal dimensions provide insight into reaction front geometry and should vary with lithology. Once the surface area discrepancy has been accounted for using this method, we find a one to two order of magnitude range in weathering advance rates measured at any scale or temperature that can be attributed to factors such as changes in erosional regime, parent lithology, mechanism, climate, composition of reacting fluid, and biological activity. Our scaled equation, when used to predict global basalt CO2 consumption based upon global lithologic maps, yields an uptake flux (1.75 × 1013 mol CO2 yr− 1) within the predicted error of fluxes estimated based upon riverine measurements.