Ozone layer on track to recover by 2060s, UN study finds

The ozone layer above the Antarctic is set to recover to 1980 levels in around four decades, and significantly earlier above the rest of the world, a UN study has found.

In a new quadrennial assessment report, the researchers confirm the phase out of nearly 99% of banned ozone-depleting substances since the Montreal Protocol was agreed more than 30 years ago.

If current policies remain in place, they expect the ozone layer to recover to 1980 values by around 2066 over the Antarctic, by 2045 over the Arctic, and by 2040 for the rest of the world.

The report highlights how positive changes in human behaviour, such as ending the use of gases like chlorofluorocarbons (CFCs), have led to fewer people being exposed to harmful ultraviolet rays from the sun – providing hope that similar action can help tackle climate change.

Commenting on the findings, the World Meteorological Organization's (WMO) secretary-general, professor Petteri Taalas, said that “ozone action sets a precedent for climate action".

He added: "Our success in phasing out ozone-eating chemicals shows us what can and must be done – as a matter of urgency – to transition away from fossil fuels, reduce greenhouse gases and so limit temperature increase."

The latest assessment has been made based on extensive studies, research and data compiled by a experts from the WMO, United Nations Environment Programme (UNEP), the US National Oceanic and Atmospheric Administration, NASA and the EU.

It also highlights how the Kigali Amendment to the Montreal Protocol in 2016 – which requires the phase down of many climate changing hydrofluorocarbon gases – could avoid 0.3–0.5°C of global warming by 2100.

Furthermore, for the first time, the panel of experts examine the potential impact of geoengineering through stratospheric aerosol injection, warning that the method could have unintended consequences on stratospheric temperatures, circulation and ozone production.

“The impact the Montreal Protocol has had on climate change mitigation cannot be overstressed,” said Meg Seki, executive secretary of the UNEP’s Ozone Secretariat. “Over the last 35 years, the Protocol has become a true champion for the environment.

“The assessments and reviews undertaken by the scientific assessment panel remain a vital component of the work of the Protocol that helps inform policy and decision-makers.”