Published: Fri, November 09, 2018
Research | By Raquel Erickson

Earth's ozone layer finally healing, says UN

Earth's ozone layer finally healing, says UN

Recovery from the holes and thinning caused by aerosol chemicals has progressed at a rate of about 1% to 3% a decade since 2000, meaning the ozone layer over the northern hemisphere and mid-latitudes should heal completely by the 2030s, if current rates are sustained.

The ozone layer's increasing health has been put down to the 1987 Montreal Protocol - an global treaty banning ozone-depleting chemicals, including chlorofluorocarbons (CFCs), alongside new technology.

The University of Colorado's Brian Toon, who wasn't part of the report, said the success doesn't mean the fight to save the ozone layer is over just yet.

The report finds that the concentration of ozone-depleting substances in the atmosphere continues to decrease, leading to an improvement in the ozone layer since the previous assessment carried out in 2014.

A United Nations study has revealed that the ozone layer is slowly recovering, and is even expected to be fully repaired by the 2060s.

Paul Newman, chief Earth scientist at Nasa's Goddard Space Flight Center, described the discovery as "really good news".

The ozone layer is one layer of the stratosphere - the mass of protective gases around our planet - and the second layer of the Earth's atmosphere.

"We're raising a flag to the global community to say, 'This is what's going on, and it is taking us away from timely recovery of the ozone layer, '" NOAA scientist Stephen Montzka, the study's lead author, said in a statement at the time.

The stratospheric ozone layer protects life on earth from harmful UV radiation.

This healing progress is attributed to worldwide initiatives under the Montreal Protocol, a global agreement that was formed more than 30 years ago in response to climate change concerns.

"We are only at a point where recovery may have started", Toon said, pointing to some ozone measurements that haven't increased yet.

However, while most of the banned damaging gases have been phased out, the study found at least one violation - having spotting that production and emission of CFC-11 unexpected increased in eastern Asia since 2012.

Further amendments to the protocol will come into effect in 2019, restricting the levels of climate change-worsening chemicals used in refrigerators and cars.

"I don't think we can do a victory lap until 2060", Newman said. Ozone is a colourless combination of three oxygen atoms kilometres above Earth's surface, it shields us from ultraviolet rays which cause skin cancer, crop damage and other problems.

As a result of the Montreal Protocol much more severe ozone depletion in the polar regions has been avoided.

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