Preparation of stimuli-responsive latexes whose colloidal stability can be reversibly switched using only CO2 as a trigger is reviewed. By incorporating CO2-responsive moieties into the formulation of an emulsion polymerization, polymer particles can be made for which stabilization originates from functional groups that are readily switched ˵on″ (charged) and ˵off″ (neutral) simply by adding or removing CO2 at atmospheric pressure. The functional groups that provide colloidal stability, typically amidines or tertiary amines, can be added in various forms such as premanufactured surfactants, functional monomers, or functional, commercially available initiators. This review focuses on the preparation, behavior, and properties of these CO2-switchable emulsion polymers. Detailed discussion is provided on how the switching behavior and latex properties are influenced by the choice of CO2-switchable moieties and the method of their incorporation into latex particles.