By Irina Petropavlovskikh, President of the International Ozone Commission and a CIRES and NOAA scientist
September 16th is the International Day for the Preservation of the Ozone Layer, celebrating the signing anniversary of the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. The Montreal Protocol is the treaty, ratified by every country in the world, that controls the production and use of ozone depleting substances (ODSs) such as chlorofluorocarbons (CFCs) and their early replacements. As a result of the Protocol, ODSs are declining and the ozone layer, including the Antarctic ozone hole, is showing signs of recovery, ensuring continued protection of life on Earth from harmful solar ultraviolet radiation. Nevertheless, the future evolution of surface solar ultraviolet radiation has important uncertainties caused by the expected changes in our climate.
The theme of the 2024 International Day for the Preservation of the Ozone Layer is “Montreal Protocol: Advancing Climate Action”. This theme acknowledges the Protocol’s accomplishments beyond its central focus of putting the world on the road to repairing the ozone layer. Specifically, as ODSs are also potent greenhouse gases, their decline has also contributed to a reduction in the warming of the climate. It is estimated that the Protocol has postponed the expected date of an ice-free Arctic by up to 15 years. The 2016 Kigali Amendment to the Protocol, ratified by 80% of the original Protocol signatories, phases down production of the ozone-safe hydrofluorocarbons (HFCs) in light of their global warming potential, in favor of newer compounds that have a smaller climate footprint.
Among the numerous and diverse studies on the ozone layer and the processes affecting it carried out over the past year, many have provided reassurances that the core factors affecting ozone layer stability are generally well understood and that ozone recovery is continuing in line with expectations.
Read more in the September 16 press release from the International Ozone Commission. For the current state of the ozone layer at the South Pole and to learn what happens to ozone during the Antarctic spring ozone season, follow this blog and visit NOAA’s South Pole Ozone Hole webpage.
