Researchers say they have found the first clear evidence that the thinning in the ozone layer above Antarctica is starting to heal.
The scientists said that in September 2015 the hole was around 4 million sq km smaller than it was in the year 2000 - an area roughly the size of India.
The gains have been credited to the long term phasing out of ozone-destroying chemicals.
The study also sheds new light on the role of volcanoes in making the problem worse.
