More accurate estimates of countries contributions to specific years, or periods, – if needed – might be obtained by adopting our methodology while constraining model output to updated sets of ad hoc forcing and observations, possibly through the use of data assimilation techniques. Globally, however, the emerging picture appears relatively robust, and the estimates provided by the proposed ecological-economics approach a sound, though rather conservative, contribution to the valuation of carbon sequestration services over the Mediterranean basin, which can be used as a source of information for carbon accounting of different states under present condition.