HYDROFLUOROCARBONS (HFCS) ARE STRONG GREENHOUSE GASES THAT CAN INDIRECTLY MODIFY THE OZONE LAYER BY CHANGING THE STRATOSPHERIC CLIMATE. RAPIDLY INCREASING HFC EMISSIONS MAY LEAD TO SIGNIFICANT STRATOSPHERIC CHANGE BY THE MID-21ST CENTURY POTENTIALLY COUNTERACTING THE OZONE AND CLIMATE BENEFITS OF THE MONTREAL PROTOCOL AND KYOTO PROTOCOL. EACH HFC COMPOUND HAS DIFFERENT CHEMICAL AND RADIATIVE PROPERTIES AND EMISSIONS GROWTH RATES AND THUS WILL HAVE DIFFERENT STRATOSPHERIC IMPACTS. WHILE RADIATIVE TRANSFER MODEL CALCULATIONS SHOW THAT HFCS WARM THE TROPICAL TROPOPAUSE PROVIDING EVIDENCE FOR THE INFLUENCE OF HFCS ON ATMOSPHERIC CIRCULATION THE FULL OZONE AND CLIMATE IMPACTS OF HFCS HAVE NOT BEEN QUANTIFIED. LIKEWISE THE CHEMISTRY AND CLIMATE BENEFITS OF LIMITING FUTURE GROWTH IN HFC EMISSIONS HAVE YET TO BE ESTIMATED. NUMERICAL CHEMISTRY-CLIMATE MODELS (CCMS) ARE THE IDEAL TOOLS FOR STUDYING THE FULL IMPACTS OF HFCS ON CLIMATE AND STRATOSPHERIC OZONE PARTICULARLY UNDER FUTURE CLIMATE CONDITIONS. THE PROPOSED RESEARCH WILL RELY ON TWO CCMS: A COMPUTATIONALLY EFFICIENT TWO-DIMENSIONAL (2D) ATMOSPHERIC CCM HELPFUL FOR MODEL DEVELOPMENT AND FOR PERFORMING MULTIPLE SENSITIVITY SIMULATIONS AND A THREE-DIMENSIONAL (3D) FULLY-COUPLED OCEAN-ATMOSPHERE CCM. USING AN OCEAN-ATMOSPHERE CCM THE IMPACTS OF HFCS ON BOTH TROPICAL AND POLAR CLIMATE AND AN ABSOLUTE ESTIMATE OF THE HFC CONTRIBUTION TO BOTH SURFACE WARMING AND STRATOSPHERIC CLIMATE CHANGE CAN BE QUANTIFIED.