The two main chemicals that eat up ozone are in lower concentrations in the atmosphere, said Newman, senior Earth scientist at NASA’s Goddard Space Flight Center. Chlorine levels have fallen 11.5 percent since their peak in 1993, and bromine, which is more efficient at depleting ozone but is in smaller amounts in the air, has fallen 14.5 percent since its peak in 1999, they said in the report.
That bromine and chlorine levels “have stopped rising and falling is real testament to the effectiveness of the Montreal Protocol,” Newman said.
“There has been a fundamental change in the way our society deals with ozone-depleting substances,” said David W. Fahey, co-chair of the scientific panel, director of the US National Oceanic and Atmospheric Administration’s Laboratory of Chemical Sciences.
Decades ago, people could walk into a store and buy a can of refrigerant that would eat up the ozone, punch a hole in it, and pollute the atmosphere, Fahey said. Now the substances are not only banned, they are not often found in people’s homes or cars and are being replaced by cleaner chemicals.
Natural weather patterns in Antarctica also affect ozone hole levels, which peak in the fall. And in the last few years, the holes have been a little bigger because of it, but the overall trend is toward healing, Newman said.
This “saves 2 million people from skin cancer every year,” Inger Andersen, director of the United Nations Environment Programme, told The Associated Press in an email earlier this year.
A few years ago, emissions of one of the banned chemicals, chlorofluorocarbon-11 (CFC-11), stopped declining and were increasing. Rogue emissions were spotted in parts of China but have now receded where expected, Newman said.
A third generation of these chemicals called HFC was banned a few years ago not because it would deplete the ozone layer, but because it is a heat-trapping greenhouse gas. The new report says the ban would avoid 0.3 to 0.5 degrees Celsius of additional warming.
The report also warned that efforts to artificially cool the planet by forcing aerosols into the atmosphere to reflect sunlight would thin Antarctica’s ozone layer by up to 20 percent.
https://www.smh.com.au/environment/climate-change/the-ozone-layer-is-on-track-to-fully-recover-by-2066-un-20230110-p5cbld.html?ref=rss&utm_medium=rss&utm_source=rss_environment Ozone hole over Antarctica to heal by 2066: UN