Clear signs that Antarctic ozone layer on the wane

The study found that the ozone hole had shrunk by 1.5 million square miles (four million square kilometres) – an area about the size of India – since 2000.

The hole won’t completely close for at least 30 years at the earliest but is opening up just a little bit less nearly every year, Solomon said.

The ozone layer is the shield that protects our skin from harmful ultraviolet radiation coming from the sun. But ozone is destroyed by reactions with chlorine and other atoms that are released by CFCs and similar chemicals, which were used for decades as refrigerants and propellants.

The ozone goes through a regular cycle each year, with depletion of ozone starting in late August at the end of Antarctica’s dark winter.

“We as a planet have avoided what would have been an environmental catastrophe”, says Susan Solomon, an atmospheric scientist at the Massachusetts Institute of Technology in Cambridge, and a pioneer in the field of Antarctic ozone loss. “That point hasn’t really been made strongly in the past”, she added.

“We can now be confident that the things we’ve done have put the planet on a path to heal, which is pretty good for us, isn’t it?” This reduction occurred despite the effects of some volcanic eruptions, including one previous year in the Chilean Andes that led to one of the largest holes ever measured. From then on, ozone depletion was typically tracked using October measurements. The researchers attribute this to the 1987 Montreal Protocol, which banned the use of chlorinated compounds in refrigerator coolants and aerosols, after scientists learned that these chemicals were making their way into the stratosphere and wreaking havoc on Earth’s ozone layer. According to this study, the ozone layer is showing signs of actively growing again. But they discovered something else, too.

Scientists are calling the new study a historic finding for the effort to mitigate the effects of climate change. “We predicted this way back in the day – we scientists said this would happen, and we said that if you do something, things will eventually get better”, he says.

“Now we’ve actually seen the planet starting to get better”.

The inherent complexity involved in parsing out trends in meteorological data makes it hard to pin down exactly how the Montreal Protocol has affected this swing in the right direction. When countries began phasing out CFCs, manufacturers replaced them with hydrofluorocarbons (HFCs).

Molecules that rip apart the ozone layer break down slowly, so even though we’re not emitting them anymore, the ones we’ve already emitted will persist for a while. News stories displayed here appear in our category for and are licensed via a specific agreement between LongIsland.com and The Associated Press, the world’s oldest and largest news organization.

It is hoped that the continuation to maintain the Montreal Protocol will lead to full ozone recovery by the mid-century.