The Ozone Hole Is Shrinking – Scientists Call It a ‘Reassuring Sign’ of Recovery

This year the hole in the ozone layer, which lies over the Antarctic, was the smallest and shortest-lived since 2019.

European space scientists described the finding as a ‘reassuring sign’ of atmospheric recovery.

The yearly gap in what scientists called ‘planetary sunscreen’ reached a maximum area of 21m sq km over the southern hemisphere in September.

This is far below the maximum of 26m sq km reached in 2023 data from the Copernicus Atmosphere Monitoring Service (Cams) shows.

It marks the second year in a row of smaller holes in the ozone layer, after a series of larger and longer-lasting holes that appeared between 2020 and 2023.

‘The earlier closure and relatively small size of this year’s ozone hole is a reassuring sign,’ said Laurence Rouil, the director of Cams, which is part of the EU’s space programme. ‘It reflects the steady year-on-year progress we are now observing in the recovery of the ozone layer thanks to the ODS (ozone-depleting substances) ban.’

What is the Ozone Layer?

The ozone layer, a stratospheric shield that protects life on Earth from ultraviolet (UV) rays, has been worn down by human-caused pollution.

The so-called ‘ozone hole’ is not an actual hole in the planet’s ozone layer, but rather a large region of Earth’s stratosphere with extremely low ozone concentrations.

Lack of ozone in the stratosphere allows more UV radiation to reach the surface of the Earth, damaging crops and increasing cases of skin cancer and cataracts.

However, since ozone-depleting chemicals were phased out by the 1987 Montreal protocol and a series of amendments that followed, the layer has begun to recover.

Scientists are still working to understand why the ozone holes were so big and persistent between 2020 and 2023, but suspect that the eruption of the Hunga Tonga volcano in 2022, which spewed ash and water vapour into the stratosphere, played a significant role.

The scientists at Cams said large holes in recent years showed the decline in global stratospheric ozone could have reached ‘catastrophic levels’ without successful agreements to phase out pollutants.

‘This progress should be celebrated as a timely reminder of what can be achieved when the international community works together to address global environmental challenges,’ said Rouil.

Paul Newman, the leader of the ozone research team at NASA’s Goddard Space Flight Center, said the change in the size of holes was following predictions.

‘They’re forming later in the season and breaking up earlier,’ he said. ‘But we still have a long way to go before it recovers to 1980s levels.’