EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Influence of Natural Halogens on Global Tropospheric Ozone During the 21st Century

Alfonso Saiz-Lopez
Alfonso Saiz-Lopez
  • Consejo Superior de Investigaciones Científicas (CSIC), Institute of Physical Chemistry Rocasolano, Madrid, Spain (

Tropospheric ozone (O3) is an important greenhouse gas relevant for global warming projections as well as secondary pollutant affecting air quality on the regional scale. In this Communication, we use halogen version of the CAM-Chem model to investigate the evolution of the O3 budget during the 21st century following two different climate scenarios (RCP6.0 and RCP8.5) and halogen emissions. Our results indicate that the global ozone net chemical change (NCC) will decrease by ~50%, notwithstanding increasing or decreasing trends in ozone production and loss. However, a wide range of surface NCC variations (from −60% to 150%) are projected over polluted regions depending on the evolution of anthropogenic O3 precursor emissions. Most notably, water vapor and iodine are found to be key drivers of future tropospheric O3 destruction, while the largest changes in O3 production are determined by the future evolution of peroxy radicals. Overall, future surface ozone destruction due to halogens will become more important moving into the future for both scenarios, reaching a net reduction from −30 to −35 Tg (−11 to −15%) on the global O3 burden.

How to cite: Saiz-Lopez, A.: Influence of Natural Halogens on Global Tropospheric Ozone During the 21st Century, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-13226,, 2023.