Alba Badia, Fernando Iglesias-Suarez , Rafael P. Fernandez , Carlos A. Cuevas, Douglas E. Kinnison, Jean-Francois Lamarque, Paul T. Griffiths, David W. Tarasick, Jane Liu and Alfonso Saiz-Lopez.
JRG Atmospheres, Volume126, Issue20, https://doi.org/10.1029/2021JD034859, 2021.
Abstract:
Tropospheric ozEone ( O3 ) is an important greenhouse gas and a surface pollutant. The future evolutiEon of O3 abundances and chemical processing are uncertain due to a changing climate, socioeconomic developments, and missing chemistry in global models. Here, we use an Earth System Model with natural halogen chemistry to investigate the changes iEn the O3 budget over the 21st century following Representative Concentration Pathway (RCP)6.0 and RCP8.5 climate scenarios. Our results indicate that the global tropospEheric O3 net chemical change (NCC, chemical gross production minus destruction) will decrease 50% , notwithstanding increasing or decreasing trends in ozone production and loss. However, a wide range of surface NCC variations (fromE −60% Eto 150% ) are projected over polluted regions with stringent abatemeEnts in O3 precursor emissions. Water vapor and iodine are found to be key drivers of future tropospEheric O3 destruction, while the largest changEes in O3 production are determined by the future evolution of peroxy radicals. We show that natural halogens, currently not considered in climate models, significantly impact on the present-day and future gElobal O3 burden redEucing 30–35 Tg (E11–15% ) of tropospheric ozone throughout the 21st century regardless of the RCP scenario considered. This highlights the importance of including natural halogen chemistry in climate model projections of future tropospheric ozone.