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Despite fears that due to the eruption of the Hunga Tonga volcano in 2022 and early projections that 2023 would result in the biggest ozone hole ever, this is not the case.

According to Paul Newman, former co-chair of the Scientific Assessment Panel to the Montreal Protocol on Substances that Deplete the Ozone Layer and leader of NASA's ozone research team and chief scientist for Earth sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, “It’s a very modest ozone hole.”

While the hole this year averaged 8.9 million square miles (23.1 million square kilometers), approximately the size of North America, he goes on to say, “Declining levels of human-produced chlorine compounds, along with help from active Antarctic stratospheric weather slightly improved ozone levels this year.”

The 2023 Antarctic ozone hole reached its maximum size at 10 million square miles, or 26 million square kilometers, on Sept. 21, which ranks it the 12th largest since 1979, according to annual satellite and balloon-based measurements made by NASA and NOAA.

Scientists keep a close watch on the size of the ozone hole each year and the ozone layer in general because of its importance in safeguarding all human life on Earth. The ozone layer acts like a sunscreen, filtering out up to 99% of harmful solar UV radiation. Extensive exposure to UV radiation can result in sunburns, skin cancer and eye cataracts and also damages animals and plants.

In 1985 the world was first alerted that a severe thinning of the ozone layer, more commonly referred to as a “hole” had been created by our use of chlorofluorocarbons (CFCs), ozone depleting substances used in everyday items such as fridges, air conditioners and aerosols. The Montreal Protocol was adopted in 1987 under which CFCs were banned. Since then, the Protocol has controlled additional ozone-depleting substances including hydrochlorofluorocarbons (HCFCs) used as substitutes for CFCs. The most recent Scientific Assessment Panel quadrennial assessment of 2022 indicates that ozone levels are slowly starting to recover and are expected to get back to pre-1980 levels by 2040. The more severe ozone loss over Antarctica will only recover around 2066.

“The full recovery of the ozone layer is a long-term project. It will require continued implementation and adherence to the Montreal Protocol. This is why we rely on our colleagues at NASA and NOAA to keep an eye on the annual ozone hole. It is vital that we know that we’re still on track or veered off course,” said Meg Seki, Executive Secretary of the Ozone Secretariat.

For more information contact:
Stephanie Haysmith, Communications & Information, Ozone Secretariat