The ozone layer carries a lesson that climate diplomacy needs.
Persistent rules changed industrial behavior and helped a damaged planetary shield begin recovering.
Good outcome probability
Global stratospheric ozone recovery will remain on a long-term upward trajectory through 2030 under existing controls.
Few environmental stories are as instructive as ozone recovery: governments identified a threat, acted collectively and kept restrictions in place for decades.
The World Meteorological Organization attributes the continuing recovery to the control of destructive substances, while cautioning against treating one year’s ozone-hole size as a definitive trend.
Progress came through unglamorous persistence. Future success depends on monitoring illicit emissions and maintaining the international institutions that made the repair possible.
What this could mean.
- Why this could be good
- Ozone absorbs ultraviolet radiation and provides protection for people, crops and ecosystems.
- Potential positive outcomes
Less harmful ultraviolet exposure could lower avoidable health risks over time.
The Montreal Protocol could guide enforcement design for other shared environmental threats.
Atmospheric surprises still make continued monitoring essential.
The assessment.
- What we are forecasting
- Global stratospheric ozone recovery will remain on a long-term upward trajectory through 2030 under existing controls.
- Time horizon
- Through December 2027
- Editorial confidence in the evidence: 96%
- WMO reports long-term ozone recovery linked to restrictions on ozone-depleting chemicals.
- What could change the outcome
- Individual seasons fluctuate, and unexpected emissions could slow progress.
The evidence.
- WMO ozone recovery bulletin ↗World Meteorological Organization · September 2026