The ozone layer above Antarctica, which had deteriorated to worrying levels, has started showing signs of improvement, scientists have said. In a new study, researchers found the “first fingerprints of healing” by measuring the amount of ozone in the stratosphere between 2000 and 2015. While the hole above the continent was approximately the size of India in 2000, it was around 4 million sq km smaller in September 2015, BBC reported.

“We don’t expect to see a complete recovery until about 2050 or 2060, but we are starting to see that in September, the ozone hole is not as bad as it used to be,” said American researcher Professor Susan Solomon, one of the authors of the study.

Scientists first noticed that the ozone layer above the Antarctic region was thinning in the mid 1980s. The primary cause was believed to be presence of chlorofluorocarbons in the atmosphere. CFC is released by products such as air conditioners, refrigerators and hairspray.

Now, scientists say the improvement is thanks to the efforts made to minimise the use of such destructive chemicals. The Montreal Protocol banned the use of CFCs worldwide in 1987. The ozone layer protects humans and animals from the harmful effects of ultraviolet rays. Without it, there are higher chances of living beings contracting cataract or skin cancer.