Earth's protective ozone layer 'on track' to recover by 2066, according to UN

The Earth's protective ozone layer is "on track" to fully recover, according to a new assessment backed by the United Nations.

A scientific assessment, found that by around 2066, over the Antarctic, by 2045 over the Arctic, and by 2040 for the rest of the world, levels should return to what they were in the 1980s.

Paul Newman, co-chair of the scientific assessment, said: "In the upper stratosphere and in the ozone hole we see things getting better."

While Meg Seki, executive secretary of the United Nations Environment Programme's ozone secretariat, added that the report delivers "fantastic news".

Scientists and environmental advocates have contributed these latest efforts to the ongoing success of the 1989 Montreal Protocol, which banned 99% ozone-depleting substances.

Having first come into force after scientists raised the alarm over a "hole" in the Earth's ozone layer, chemicals that were found to deplete the upper stratospheric layer were banned.

Mr Newman went on to explain that the two chief chemicals that "munch away" at the ozone - bromine and chlorine - have "stopped growing" and levels are "coming down," another testament to the effectiveness of the Protocol.

In a 2016 update of the Protocol, known as the Kigali amendment, countries agreed to phase down the production and consumption of other compounds known to have a powerful effect on global warming.

The new assessment said the Kigali amendment is estimated to avoid 0.3C to 0.5C of global warming by 2100.

It also says that new studies support previous assessments that the decline in ozone-depleting substance emissions avoids an additional 0.5C to 1C of global warming by mid-century.

Ms Seki said: "Over the last 35 years, the Protocol has become a true champion for the environment."

The panel also examined the potential effects of a proposed deliberate addition of aerosols into the stratosphere - known as stratospheric aerosol injection - in order to reflect more sunlight and reduce warming.

It cautioned that the unintended consequences of this process could thin the ozone layer by as much as 20% in Antarctica.