The Potential effects of increased methane on atmospheric ozone

Using a one dimensional atmospheric model, we investigate the possible influence of an increase in atmospheric methane on ozone. The couplings between methane and the catalytic destruction of ozone by NOx, HOx, and ClX are discussed. Our model calculations suggest that doubling the ground-level flux of methane, with fixed atmospheric temperatures and currently recommended chemical reaction rates, would increase the total ozone column by 3.5%. Calculations showing the very significant moderating effects of a methane increase on ozone perturbations due to N2O and chlorofluorocarbons are discussed.