DOI:
10.1038/s41586-023-06119-z
IAA authors:
Gómez Martín, Juan Carlos
Authors:
Saiz-Lopez, Alfonso;Fernandez, Rafael P.;Li, Qinyi;Cuevas, Carlos A.;Fu, Xiao;Kinnison, Douglas E.;Tilmes, Simone;Mahajan, Anoop S.;Gómez Martín, Juan Carlos;Iglesias-Suarez, Fernando;Hossaini, Ryan;Plane, John M. C.;Myhre, Gunnar;Lamarque, Jean-François
Abstract:
Observational evidence shows the ubiquitous presence of ocean-emitted short-lived halogens in the global atmosphere<SUP>1-3</SUP>. Natural emissions of these chemical compounds have been anthropogenically amplified since pre-industrial times<SUP>4-6</SUP>, while, in addition, anthropogenic short-lived halocarbons are currently being emitted to the atmosphere<SUP>7,8</SUP>. Despite their widespread distribution in the atmosphere, the combined impact of these species on Earth's radiative balance remains unknown. Here we show that short-lived halogens exert a substantial indirect cooling effect at present (−0.13 ± 0.03 watts per square metre) that arises from halogen-mediated radiative perturbations of ozone (−0.24 ± 0.02 watts per square metre), compensated by those from methane (+0.09 ± 0.01 watts per square metre), aerosols (+0.03 ± 0.01 watts per square metre) and stratospheric water vapour (+0.011 ± 0.001 watts per square metre). Importantly, this substantial cooling effect has increased since 1750 by −0.05 ± 0.03 watts per square metre (61 per cent), driven by the anthropogenic amplification of natural halogen emissions, and is projected to change further (18-31 per cent by 2100) depending on climate warming projections and socioeconomic development. We conclude that the indirect radiative effect due to short-lived halogens should now be incorporated into climate models to provide a more realistic natural baseline of Earth's climate system.
URL:
https://ui.adsabs.harvard.edu/#abs/2023Natur.618..967S/abstract