Quantifying the ozone and ultraviolet benefits already achieved by the Montreal Protocol

Chlorine- and bromine-containing ozone-depleting substances (ODSs) are controlled by the 1987 Montreal Protocol. In consequence, atmospheric equivalent chlorine peaked in 1993 and has been declining slowly since then. Consistent with this, models project a gradual increase in stratospheric ozone wit...

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Bibliographic Details
Published in:Nature Communications
Main Authors: Chipperfield, MP, Dhomse, SS, Feng, W, McKenzie, RL, Velders, GJM, Pyle, JA
Format: Article in Journal/Newspaper
Language:English
Published: Nature Publishing Group 2015
Subjects:
Online Access:https://eprints.whiterose.ac.uk/86454/
https://eprints.whiterose.ac.uk/86454/7/ncomms8233.pdf
https://doi.org/10.1038/ncomms8233
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Summary:Chlorine- and bromine-containing ozone-depleting substances (ODSs) are controlled by the 1987 Montreal Protocol. In consequence, atmospheric equivalent chlorine peaked in 1993 and has been declining slowly since then. Consistent with this, models project a gradual increase in stratospheric ozone with the Antarctic ozone hole expected to disappear by ∼2050. However, we show that by 2013 the Montreal Protocol had already achieved significant benefits for the ozone layer. Using a 3D atmospheric chemistry transport model, we demonstrate that much larger ozone depletion than observed has been avoided by the protocol, with beneficial impacts on surface ultraviolet. A deep Arctic ozone hole, with column values <120 DU, would have occurred given meteorological conditions in 2011. The Antarctic ozone hole would have grown in size by 40% by 2013, with enhanced loss at subpolar latitudes. The decline over northern hemisphere middle latitudes would have continued, more than doubling to ∼15% by 2013.