A fluorescent turn-on chemosensor for CO2 was developed using intra-molecular hydrogen bonding stabilization. The chemosensor (sodium (anthracen-9-ylmethyl)glycinate (1)) reacts with CO2 and forms chemosensor-CO2 adduct stabilized by strong intra-molecular hydrogen bonds. The stabilization consequently allows sensing CO2 with high sensitivity and the detection limit of this chemosensor for CO2 was estimated to be ∼2 ppm. In addition, the chemosensor was applied to develop an easy screening protocol to evaluate the efficiency of CO2 absorbents. The protocols discriminate the relative ability of CO2 absorbents as strong, intermediate, and weak using easily measured fluorescence changes.