Abstract/Summary

We calculate ozone radiative forcing (RF) and stratospheric temperature adjustments for the period 1850-2014 using the newly availableCMIP6 ozone dataset. The CMIP6 total ozone RF (1850s-2000s) is 0.28+/-0.17 W m-2 (which is 80% higher than our CMIP5 estimation), and 0.30+/-0.17 W m-2 out to the present day (2014). The total ozone RF grows rapidly until the 1970s, slows towards the 2000s, and shows a renewed growth thereafter. Since the 1990s the shortwave RF exceeds the longwave RF. Global stratospheric ozone RF is positive between 1930 and 1970 and then turns negative, but remains positive in the Northern Hemisphere throughout. Derived stratospheric temperature changes show a localized cooling in the subtropical lower stratosphere due to tropospheric ozone increases, and cooling in the upper stratosphere due to ozone depletion by more than 1K already prior to the satellite era (1980), and by more than 2K out to the present day(2014).