For both NNP and classical models, the desorption barrier of CO 2 from the interface to the air phase is observed to be lower than the barrier for transport into the aqueous phase. The free energy of CO 2 desorption from the classically modeled interface to the air phase is ∼ -0.7 kcal/mol lower than that from the NNP-modeled interface (Figure ). Similarly, the free energy required for CO 2 transport from the interface to the aqueous phase is ∼ -0.65 kcal/mol lower for the classical model compared to the NNP model. Other classical models showed similar PMFs compared to SPC/E (Figure ). Despite these variations, both the NNP and classical models reveal consistent differences in the thermodynamics of CO 2 adsorption and desoprtion. Collectively, these results suggest that a CO 2 molecule at the interface is more likely to move to the air phase than into the aqueous phase. To quantify how these barriers affect the rates of transport, we employed transition state theory in the harmonic approximation to obtain and compare the rate constants (k) for CO 2 desorption and transport into the aqueous phase using the equation: