The present invention is generally directed to a system for recovering CO.sub.2 from seawater or aqueous bicarbonate solutions using a gas permeable membrane with multiple layers. At elevated pressures, gaseous CO.sub.2 and bound CO.sub.2 in the ionic form of bicarbonate and carbonate diffuse from the seawater or bicarbonate solution through the multiple layers of the membrane. Also disclosed is the related method of recovering CO.sub.2 from seawater or aqueous bicarbonate solutions.