The World Avoided by the Montreal Protocol
Article first published online: 28 AUG 2008
Copyright 2008 by the American Geophysical Union.
Geophysical Research Letters
Volume 35, Issue 16, August 2008
How to Cite
2008), The World Avoided by the Montreal Protocol, Geophys. Res. Lett., 35, L16811, doi:10.1029/2008GL034590., , , , , , and (
- Issue published online: 28 AUG 2008
- Article first published online: 28 AUG 2008
- Manuscript Accepted: 28 JUL 2008
- Manuscript Revised: 11 JUL 2008
- Manuscript Received: 6 MAY 2008
- stratosphere-troposphere coupling;
- Montreal Protocol
 The impact of increased stratospheric chlorine, averted by controls imposed by the Montreal Protocol, is studied using the UKCA chemistry-climate model. We contrast an atmosphere with 9 ppbv Cly, which could have occurred by ∼2030, with the present-day loading (3.5 ppbv), and consider the response of climate to resulting ozone perturbations, disregarding the radiative impact of the additional CFCs. Ozone columns decline everywhere, with climate impacts in both polar regions. The additional chlorine leads to a strengthening of the Southern Annular Mode, versus the reference, and Antarctic surface temperature differences resemble observed changes. Over Eurasia, winter surface temperature changes project on the Northern Annular Mode. These high-latitude temperature perturbations (>1 K) are larger than the global mean temperature rises projected over the next few decades, and perhaps comparable with projected regional changes. The Montreal Protocol has not only averted further damage to the ozone layer but has helped prevent significant regional climate change.