The need for mass balance and feedback in the geochemical carbon cycle: Reply
Mike J. Bickle
A response to Berner and Caldeira's paper regarding the role of mountain uplift in the long term stabilization of the carbon cycle.
Berner and Caldeira (1997) addressed long-standing but unanswered questions about the long-term controls on atmospheric CO2, levels including the necessity for, and nature of, the feedback mechanisms between climate and atmospheric CO2. Their main point, that the stability of global climate over the long term requires a feedback between climate and silicate weathering rates, is well put. However, they miss an important subtlety in climate control by mountain uplift, which may have fundamental implications for long-term variations in global climate, in addition to providing compelling support for the significance of the feedback relationship. Collisional orogens may produce significant CO2 fluxes, as well as significantly increase the weatherability of the crust; these have opposite consequences for climate.