A low-voltage, low-energy electrochemical system and method of removing protons and/or producing a base solution comprising hydroxide and carbonate/bicarbonate ions, utilizing carbon dioxide in a cathode compartment that is partitioned into a first cathode electrolyte compartment and a second cathode electrolyte compartment such that liquid flow between the cathode electrolyte compartments is possible, but wherein gaseous communication between the cathode electrolyte compartments is restricted. Carbon dioxide gas in one cathode electrolyte compartment is utilized with the cathode electrolyte in both compartments to produce the base solution with less that 3V applied across the electrodes.