Back when I was in middle school, big hair, made possible through large amounts of aerosol hairspray, was a thing. Do you know what else was discovered to be a thing? A big hole in the ozone layer over the Antarctic was growing, and likely part of the reason for increased skin cancer levels. In very short order, the world came together in one of the greatest examples of multinational teamwork I can identify, and following the advice of scientific research, they banned the use of a lot of ozone layer depleting chemicals like freon, and that hairspray I used so much got changed from aerosol to pump, and things went from the fuzzy, big hair of the 80s to the crunchy locks of the 90s.
Haircare aside, because of our actions, the ozone hole in the south has been reduced over time.
The Northern Ozone Layer had been saved from seasonal depletion by a trick of the lack of landscape. While the Antarctic warmed in the summer, allowing a high-altitude vortex to warm the atmosphere, the sea ice and oceans of the north lacked that kind of dynamic heating, and without the heating, no ozone hole had been seen.
The record-high North Pacific sea surface temperatures of spring 2020 brought with them the dynamical heating needed to create an Arctic ozone hole. According to study lead author Youngyun Hu: The formation of the record Arctic ozone loss in spring 2020 indicates that present-day ozone-depleting substances are still sufficient to cause severe springtime ozone depletion in the Arctic stratosphere. These results suggest that severe ozone loss is likely to occur in the near future as long as North Pacific warm SST anomalies or other dynamical processes are sufficiently strong.”
This one-two punch of our past pollutants and the warming Arctic is just one more source of existential dread that will keep me awake at night.
“Record Arctic Ozone Loss in Spring 2020 is Likely Caused by North Pacific Warm Sea Surface Temperature Anomalies,” Yan Xia et al., 2021 July 10, Advances in Atmospheric Sciences