The last report published under the Montreal Protocol – Scientific Assessment of Ozone Depletion (2022) – announces a major achievement:
Actions taken under the Montreal Protocol continue to contribute to ozone recovery. Recovery of ozone in the upper stratosphere is progressing. Total Column Ozone (TCO) in the Antarctic continues to recover, notwithstanding substantial interannual variability in the size, strength, and longevity of the ozone hole. Outside of the Antarctic region (from 90°N to 60°S), the limited evidence of TCO recovery since 1996 has low confidence. TCO is expected to return to 1980 values around 2066 in the Antarctic, around 2045 in the Arctic, and around 2040 for the near-global average (from 60°N to 60°S). The assessment of the depletion of TCO in regions around the globe from 1980–1996 remains essentially unchanged since the 2018 Assessment.
Source: NASA Ozone Watch.
Figure 1: Ozone Maps from Northern Hemisphere (left column) and Southern Hemisphere (right column). The blue and purple colors show where there is the least ozone. The yellow and red colors show where there is more ozone.
Final thoughts
I confess that I was quite pessimistic about the healing of the ozone layer. But I am not anymore. It seems that mother nature has its own way of healing, with a little bit of support from us, humans. I hope that the same will happen with the global warming.
References:
- World Meteorological Organization (WMO). Executive Summary. Scientific Assessment of Ozone Depletion: 2022, GAW Report No. 278, 56 pp.; WMO: Geneva, 2022.
https://ozone.unep.org/system/files/documents/Scientific-Assessment-of-Ozone-Depletion-2022-Executive-Summary.pdf
The ozone map for the Southern Pole from September 2019 (this is when the spring begins in the Southern Hemisphere) shows quite a bit of improvement, even though the worldwide economy was up and running at its full potential. That improvement seems to have evaporated in 2020-2022, despite the fact that during the pandemic the worldwide economy slowed down considerably.
I did not find any explanation for this fact. If you are aware of such an explanation, please post it in the Comments section.