RADIATIVE FORCING OF CLIMATE BY CHANGES IN THE VERTICAL-DISTRIBUTION OF OZONE

The method employs a parameterization based on one-dimensional radiative-convective equilibrium calculations; these calculations predict that the surface temperature should warm in response to both decreases in ozone above 30km and increases in ozone below 30km. We show that observed ozone trends, taken at face value, suggest a cooling of the surface temperature at northern mid-latitudes during the 1970s equal in magnitude to about half the warming predicted for CO2 for the same time period. However, the measurement uncertainty of the observed trends is large, with the best estimates for mid-latitude cooling being -0.05±0.05°C. The surface cooling is caused by ozone decreases in the lower stratosphere, which outweigh the warming effects of ozone increases in the troposphere. -from Authors