Effects of Strongly Enhanced Atmospheric Methane Concentrations in a Fully Coupled Chemistry-Climate Model

This study investigates the impact of strongly increased atmospheric methane mixing ratios on the Earth's climate. An interactive model system including atmospheric dynamics, chemistry, and a mixed layer ocean model is used to analyse the effect of doubled and fivefold methane mixing ratios. We assess feedbacks on atmospheric chemistry and changes in the stratospheric circulation, focusing on the impact of tropospheric warming, and their relevance for the model's climate sensitivity