Does silicate weathering, the hypothesized feedback mechanism for stabilizing atmospheric CO2 concentrations on geologic time scales, demonstrably increase with the observed increase in atmospheric CO2 concentrations?

Over then next 50-100 years, while atmospheric CO2 concentrations continue to increase, we are in the unique position to test whether the silicate weathering feedback mechanism exerts the hypothesized control on atmospheric carbon dioxide concentrations. The groundwork for answering this question has to be laid now to be able to track the response of the “critical zone” (biotic and abiotic weathering and erosion processes, including land-to-sea transport of weathering products) to changing global environmental conditions. One of the challenges is to distinguish the “natural” response of the Earth System from ongoing anthropogenic modifications of this system.