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Keywords:

  • ozone;
  • climate;
  • stratosphere

[1] The impact of increasing greenhouse gases (GHGs) on the “recovery” of stratospheric ozone is examined using simulations of the Goddard Earth Observing System Chemistry-Climate Model. In this model, GHG-induced climate change has a large impact on the ozone evolution and when O3 recovery milestones are reached. The two distinct milestones of “O3 returning to historical values” and “O3 being no longer significantly influenced by ozone depleting substances (ODSs)” can be reached at very different dates, and which occurs first varies between regions. GHG-induced cooling in the upper stratosphere causes O3 to increase, and O3 returns to 1980 or 1960 values several decades before O3 is no longer significantly influenced by ODSs. In contrast, transport changes in the tropical and southern mid-latitude lower stratosphere cause O3 to decrease. Here O3 never returns to 1980 values, even when anthropogenic ODSs have been removed from the atmosphere. O3 returning to 1960 (or 1980) values should not necessarily be interpreted as O3 recovery from the effects of ODSs.