Hole in ozone layer mending; to heal by 2066: UN report

According to a recent United Nations report, the Earth's protective ozone layer is slowly but visibly healing at a rate that would completely close the hole above Antarctica in 43 years.

More than 35 years after every country in the world agreed to stop producing chemicals that eat away at the layer of ozone in the Earth's atmosphere that protects the planet from harmful radiation linked to skin cancer, cataracts, and crop damage, a once-every-four-years scientific assessment found recovery in progress.

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

The research, which was published on Monday at the American Meteorological Society convention in Denver, states that the progress is slow. It will take until around 2040 for the average amount of ozone in the atmosphere to return to its 1980 pre-thinning levels at 18 miles (30 kilometres) height, according to the paper. Furthermore, the Arctic won't return to normal until 2045, Associated Press reported.

According to a source, Antarctica won't be entirely fixed until 2066 because the atmosphere there is so thin that a gigantic gaping hole forms every year.

One of the greatest ecological achievements for humanity, according to scientists and environmentalists worldwide, has been the attempt to close the ozone hole, which was made possible by the 1987 Montreal Protocol, which outlawed a group of chemicals often found in refrigerants and aerosols.

“Ozone action sets a precedent for climate action. Our success in phasing out ozone-eating chemicals shows us what can and must be done – as a matter of urgency — to transition away from fossil fuels, reduce greenhouse gases and so limit temperature increase,” World Meteorological Organization Secretary-General Prof. Petteri Taalas said in a statement.

Four years ago, there were reported signs of healing, but they were small and more preliminary. “Those numbers of recovery have solidified a lot,” Newman said.

According to Newman, chief Earth scientist at NASA's Goddard Space Flight Center, the two main compounds that eat away at ozone are present in the atmosphere at lesser concentrations. The amount of chlorine in the air has decreased by 11.5 per cent since its peak in 1993, while the amount of bromine, which is more effective at consuming ozone but is present in lower concentrations, has decreased by 14.5 per cent since its 1999 peak.

That bromine and chlorine levels “stopped growing and is coming down is a real testament to the effectiveness of the Montreal Protocol,” Newman said.

“There has been a sea change in the way our society deals with ozone-depleting substances,” said scientific panel co-chair David W. Fahey, director of the US National Oceanic and Atmospheric Administration’s chemical sciences lab.

In the past, refrigerants that deplete the ozone layer, pierce it and contaminate the atmosphere could be purchased in a can from a store, according to Fahey. In addition to being prohibited, the compounds are no longer commonly found in homes or automobiles since they have been replaced by cleaner chemicals.

Ozone hole levels, which reach their highest in the fall, are influenced by natural weather patterns in the Antarctic. And as a result, the holes have gotten a little bit bigger over the previous couple of years, but overall, healing is the trend, according to Newman.

Inger Andersen, director of the United Nations Environment Programme, stated in an email to The Associated Press earlier this year that this "saves 2 million people every year from skin cancer."

Chlorofluorocarbon-11 (CFC-11) emissions, one of the substances that are prohibited, started to increase a few years ago rather than decrease. Rogue emissions were observed in some areas of China, but they have since returned to normal, according to Newman.

A third generation of those compounds, known as HFC, was outlawed a few years ago because of its ability to trap heat and not because it would eat away at the ozone layer. According to the new analysis, the prohibition would prevent additional warming of 0.5 to 0.9 degrees (0.3 to 0.5 degrees Celsius).

The paper also stated that Antarctica's ozone layer could decrease by up to 20% as a result of efforts to artificially cool the planet by spraying aerosols into the atmosphere to reflect sunlight.