Quantifying ozone recovery: new scientific study confirms Montreal Protocol’s success in reducing Antarctic ozone depletion

Within the Earth’s stratosphere, ozone is a naturally occurring gas which protects the planet from the sun’s harmful ultraviolet radiation. Ozone-depleting substances (ODSs), chlorofluorocarbons (CFCs) have been identified as the primary cause of the ozone ‘hole’ discovered over the Antarctic in 1985.

 

Following reductions of ODSs under the Montreal Protocol, signs of ozone recovery have been reported (see our previous article), and qualitative observations suggest that the ozone hole seem to be shrinking every year ^[1].

 

A new study published in March 2025 now confirms these observations using rigorous quantitative methodology ^[2]. The team of scientists from the Massachusetts Institute of Technology, Woods Hole Oceanographic Institution, National Center for Atmospheric Research, University of Washington, New Mexico Institute of Mining and Technology, and California Institute of Technology in the USA used satellite observations together with single-model and multi-model ensemble simulations to identify and quantify the effect of human reductions in ODSs on the recovery of the ozone hole.

 

Drawing on 15 years of observational records, this study is the first to quantify with 95% confidence the positive impact of CFCs reduction on ozone recovery.

According to the quadrennial report of the Montreal Protocol Scientific Review Panel released in January 2023, if current ODS regulations remain in place, the ozone layer could return to 1980 levels by around 2066 over Antarctica, around 2045 over the Arctic and by 2040 in the rest of the world.

 

 

Sources

[1] https://climate.mit.edu/posts/study-ozone-hole-healing-thanks-global-reduction-cfcs

[2] Wang, P., Solomon, S., Santer, B.D. et al. Fingerprinting the recovery of Antarctic ozone. Nature (2025). https://doi.org/10.1038/s41586-025-08640-9