Scientists report that the Antarctic ozone hole in 2025 is the [1]fifth-smallest since 1992 , thanks largely to decades of global restrictions on ozone-depleting chemicals under the [2]Montreal Protocol . ABC News reports:

> The ozone hole reached its greatest one-day extent for 2025 in early September, measuring 8.83 million square miles, about 30% smaller than the largest hole on record in 2006. NOAA and NASA scientists emphasize that recent findings show efforts to limit ozone-depleting chemical compounds can have a significant impact. The regulations are established by the Montreal Protocol, which went into effect in 1992. Subsequent amendments are driving the gradual recovery of the ozone layer, which remains on track to fully recover later this century as countries worldwide replace harmful substances with safer alternatives.

>

> For decades, chlorofluorocarbons (CFCs) and other ozone-depleting compounds were widely used in aerosol sprays, foams, air conditioners and refrigerators, causing significant reductions in ozone levels. Natural factors, such as temperature and atmospheric circulation, also influence ozone concentrations and are likely to have contributed to a smaller ozone hole this year, according to researchers.

"This year's hole would have been more than one million square miles larger if there was still as much chlorine in the stratosphere as there was 25 years ago," said Paul Newman, a senior scientist at the University of Maryland system and longtime leader of NASA's ozone research team.



[1] https://abcnews.go.com/US/ozone-hole-ranked-5th-smallest-30-years-new/story?id=127840875

[2] https://www.unep.org/ozonaction/who-we-are/about-montreal-protocol