Abstract

I will present two central results from my PhD thesis. Using an atmosphere-ocean coupled climate model, I investigated links between the model representation of the atmospheric trace gas ozone and surface climate change projections for a standard climate sensitivity experiment. I found that:

1) circulation-driven ozone changes in the tropical upper troposphere and lower stratosphere (UTLS) can have a highly significant influence on climate sensitivity estimates.

2) the representation of ozone in the UTLS can also have a major impact on the response of the Walker circulation and the El Niño Southern Oscillation to carbon dioxide forcing.

These (surprising) results are explained mechanistically, with an emphasis on how future modelling studies could address similar research questions effectively. Time allowing, I will further discuss modelling results on how solar and sulphate geoengineering schemes might affect human exposure to ultra-violet radiation and air quality.