A process for sequestrating carbon emitted into the atmosphere in the form of CO2 comprises: a) a step for concentrating CO2 in the liquid phase; b) a step for electro-reduction in an aprotic medium to a compound in which the carbon changes to oxidation number +3 in the form of oxalic acid or formic acid; c) if appropriate, a step for re-extracting oxalic or formic acid in the aqueous phase; and d) a step for mineralization by reaction with a compound of an element M, resulting in a stable compound in which the atomic ratio C/M is about 2/1.