For the first time in 30 years, the gaping hole in the ozone layer above Antarctica appears to be healing. A new study, published in Science, reports that the phase-out of chlorofluorocarbons (CFCs) has led to a slow recovery of the ozone hole.
According to the study, whose lead author is MIT’s Susan Solomon, the size of the September ozone hole has shrunk by approximately 1.5-million-square miles since 2000. The scientists were also able to separate ozone damage due to volcanic eruptions from manmade damage, demonstrating that changes in human behavior have made a significant impact on its recovery.
Solomon, the Ellen Swallow Richards Professor of Atmospheric Chemistry and Climate Science, has spent more than three decades studying atmospheric chemistry. In 1986, she was among the first to recognize the cause of the Antarctic ozone hole and how its size changes over the course of the year. Her work was the basis of the 1987 Montreal Protocol, an international treaty to ban ozone-depleting chemicals like CFCs.
In an interview with the Guardian, Solomon described Antarctica as “the canary in the coal mine that showed us that if we didn’t back off with these chemicals, we’d have a crisis.”
Another key finding of the study explained why, in spite of this healing, the hole reached peak size in October 2015. Volcanic activity also depletes ozone by releasing sulfur dioxide into the stratosphere. Researchers were able to tie the October spike to the eruption of volcano Calbuco in Chile. “When volcanoes team up with man-made chlorine, it’s a toxic mix and Antarctica is particularly vulnerable,” explained Solomon.
In spite of potential steps backward due to volcanoes, researchers are optimistic that the hole will eventually disappear, likely around 2050.
As for Solomon, she is hopeful that the global community might come together to combat climate change in the same way it helped heal the ozone layer. She noted, “It was amazing to see how quickly innovation solved the problem with CFCs so we got rid of them yet still have hair spray and air conditioning. We’re starting to see the same thing with global warming. We should look at the ozone problem and realize that nations can get together and come up with solutions.”