40 years later: What happened to the hole in the ozone layer?
The 1985 discovery by scientists at the British Antarctic Survey identified a dramatic thinning of the ozone layer over our southernmost continent, triggering immediate global concern about potential harm to human health and ecosystems worldwide.
Located in the stratosphere, the ozone layer acts like sunscreen, blocking potentially harmful ultraviolet energy from reaching our planet's surface. Without it, humans and animals could experience increased rates of skin cancer, DNA damage, cataracts and other ailments. It also affects the physiological and developmental processes of plants.
"The discovery of the ozone hole stands as one of the most important environmental discoveries of the 20th century and demonstrates how robust science, clear communication and international cooperation can address planetary-scale threats," said Dominic Hodgson, interim director of science at the British Antarctic Survey, in a statement released May 13.
Jon Shanklin, now an emeritus fellow at the British Antarctic Survey, added that "publishing our findings in Nature 40 years ago, we couldn't have anticipated the global response that would follow."
More: Study: Ozone hole over Antarctica beginning to heal
Scientists determined the production of chlorofluorocarbons (CFCs), which were widely used in refrigeration, aerosols, solvents, and fire extinguishers caused the problem.
When chlorine and bromine atoms from CFCs rise and come into contact with ozone in the stratosphere, they destroy ozone molecules, the Environmental Protection Agency says in an online report. Ozone can be destroyed more quickly than it is naturally created, the EPA said.
A large and deep ozone hole still forms every Antarctic spring, being deepest and largest toward the end of September, Shanklin told USA TODAY in a May 15 e-mail. "There is a very slow recovery, but we'll still have ozone holes for another 50 years or more."
Indeed, though the Antarctic ozone hole shows signs of recovery, the healing process is very slow. CFCs have atmospheric lifetimes of more than 50 years, so even without further emissions, a full recovery might not occur until after 2070, the BAS said.
"The current rate of recovery is a bit slower than might be expected, so there could be feedbacks with climate change taking place," Shanklin told USA TODAY.
More: Ozone hole shrinks to smallest size on record, and it's not related to global warming
The discovery of the ozone hole led directly to the Montreal Protocol just two years later – an agreement that froze the production and use of ozone-depleting substances at 1986 levels and set the groundwork for phasing them out entirely.
Today, the protocol stands as one of the most successful international environmental treaties ever implemented. By preventing harmful UV radiation from reaching the Earth's surface, the agreement has saved thousands of lives, the BAS said.
"The Montreal Protocol is a very successful treaty that all the world's governments have signed. It is working, with the amount of ozone depleting chemicals in the atmosphere declining as expected," Shanklin said in an e-mail to USA TODAY.
USA TODAY asked Shanklin if there is a regret that we haven't made similar progress in reducing the human-caused greenhouse gas emissions that cause climate change.
"Very much so," Shanklin answered. "The Montreal Protocol shows what can be done, but with most other environmental issues (climate, biodiversity loss, sewage pollution, soil degradation, etc.) there is mostly talk and small-scale action."
"It is largely because the economic model is flawed and perverse – it assumes that resources are infinite and that there is no cost in using them," Shanklin said. "This perversely then creates all the crises that we could be avoiding."
This article originally appeared on Evening World: 40 years: What happened to the hole in the ozone layer?
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