A new ACPD article by H. Zhang and co-authors investigates the effects of recovering stratospheric ozone on tropospheric chemistry and air quality using the global chemistry-transport model GEOS-Chem. They find that surface ozone photolysis rates decrease significantly while ozone lifetime in the troposphere increases by up to 7% and the tropospheric ozone burden increases slightly (0.78%). Perturbations of tropospheric and surface ozone show large seasonal and spatial variations, with increases of up to 5% for some regions. The full abstract can be found here.