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The World Avoided by the Montreal Protocol
Author(s) -
Morgenstern Olaf,
Braesicke Peter,
Hurwitz Margaret M.,
O'Connor Fiona M.,
Bushell Andrew C.,
Johnson Colin E.,
Pyle John A.
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2008gl034590
Subject(s) - montreal protocol , ozone layer , climatology , environmental science , atmospheric sciences , ozone , ozone depletion , atmosphere (unit) , climate change , latitude , atmospheric temperature , mode (computer interface) , polar , stratosphere , meteorology , geography , geology , physics , oceanography , geodesy , astronomy , computer science , operating system
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 Cl y , 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.