World Ozone Day
Context
World Ozone Day is observed annually on 16 September to commemorate the signing of the Montreal Protocol. In 2026, the observance also marks a decade since the adoption of the Kigali Amendment, adopted in 2016.
Ozone Layer
- The ozone layer is primarily located in the stratosphere, roughly 10 to 40 km above Earth’s surface.
- It plays a crucial protective role by absorbing a significant portion of the Sun’s harmful ultraviolet B (UV B) radiation, thereby reducing its impact on life on Earth.
Montreal Protocol, 1987
- The Montreal Protocol is an international environmental agreement designed to control and gradually eliminate the production and consumption of ozone depleting substances (ODS).
- It targets nearly 100 controlled substances, including chlorofluorocarbons (CFCs) and other chemicals responsible for ozone depletion.
- The agreement is widely regarded as a major example of coordinated international action for protecting the ozone layer.
Kigali Amendment
- Adopted in 2016 and coming into effect in 2019, the Kigali Amendment strengthened the Montreal Protocol by bringing hydrofluorocarbons (HFCs) under its control.
- HFCs do not significantly deplete ozone, but many of them have a high global warming potential. Their phasedown therefore provides both climate and ozone related benefits.
- The amendment provides for an 80 to 85% reduction in HFC consumption over time, with different timelines for developed and developing country groups.
- Full implementation has been projected to help avoid up to 0.5°C of global warming by 2100.
Status of Ozone Layer Recovery
- The global ozone layer is showing a long-term recovery trend, supported by the progressive phase out of nearly 99% of controlled ozone depleting substances under the Montreal Protocol.
- According to the 2022 UNEP WMO Scientific Assessment of Ozone Depletion, ozone levels outside the polar regions are projected to return to approximately 1980 levels around 2040.
- Arctic ozone is projected to recover around 2045, while Antarctic ozone is expected to return to 1980 levels around 2066.