The UN released a report this week showing the ozone layer is healing, with the hole over the South Pole expected to close completely by 2060.

The Scientific Assessment of Ozone Depletion: 2018 has shown a continued decrease in ozone-depleting substances in the Earth's atmosphere since 2000.

The ozone layer is the term for the layer of ozone that appears in the Earth's atmosphere 15km to 30km above the planet's surface (ozone is oxygen with three oxygen atoms, while the stuff we breathe consists of two atoms).

The depletion of the ozone layer was discovered in 1974 and the famous hole in ozone above the Antarctic was discovered in the mid-1980s.

The Montreal Protocol is an international agreement that was signed in 1987 to protect the ozone layer, and in 2012 became the first international environmental treaty to be ratified by every nation, when South Sudan signed up.



The ozone layer has recovered steadily over the past 18 years and at the current rate of chlorofluorocarbon (CFC) depletion, the layer should heal completely by the 2030s.

However, the polar regions will take until the 2060s to heal because CFCs have caused more damage there.

CFCs were commonly used as refrigerants and aerosol propellants until the end of 2010, when they were phased out by the Montreal Protocol in developing countries, 15 years after developed nations were required to stop their use.



Dr Olaf Morgenstern, a climate scientist and one of the reviewers of the UN report, told BuzzFeed News that the lead finding is that "the total amount of chlorine and bromine in the atmosphere is coming down slowly over time".

Morgernstern is quick to point out that the report doesn't exclusively contain good news — the scientists also found that in the last three years there has been slightly increased CFC presence in the atmosphere, suggesting that a nation (or nations) is shirking the rules.

"On the other hand, two leading species in that group [two types of CFCs] have emissions that were not anticipated ... if there is production going on that would be illegal, criminal activity and we have to assume that's happening. In the history of the Montreal Protocol, this is the most blatant violation of the treaty."

The UN says the Ozone Depletion report illustrates the success of the Montreal Protocol. The UN also says the positive outcome will be strengthened by the Kigali Amendment to the protocol, which will be set in motion next year.

The amendment will phase out hydrofluorocarbons (HFCs), which were actually used in refrigerants and air conditioners to replace CFCs before scientists cottoned on to the fact that they act as a greenhouse gas, with a potency up to 4,100 times that of carbon.

So, does the ozone layer healing mean that climate change will slow down?

Well no, not really.

Morgernstern says that closing of the ozone hole will have only a "moderate" effect on climate change, as changes to the ozone layer only have a minimal effect on global warming.

"The amount of global warming avoided because these CFCs disappear is measured in a few tenths of a degree," said Morgernstern.



Morgernstern says the UN report represents a promising environmental outcome and that if ozone didn't exist "there would've been no land-based life forms on the planet".