Steric bulk controls CO2 absorption: N‐substituted amino acidsalts in poly(ethylene glycol) reversibly absorb CO2 in nearly 1:1 stoichiometry. Carbamic acid is thought to be the absorbed form of CO2; this was supported by NMR and in situ IR spectroscopy, and DFT calculations. The captured CO2 could be converted directly into oxazolidinones and thus CO2 desorption could be sidestepped.