Just a few weeks ago, scientists from the European Space Agency (ESA) discovered the largest hole in the ozone layer ever in the Arctic—a hole that covered an area roughly three times the area of Greenland. But scientists at the Copernicus' Atmosphere Monitoring Service (CAMS), who were monitoring the progress of the hole, have now declared that this hole has closed up—just as suddenly as it had appeared.
While this may seem like good news for the environment—people have been freaking out over the ozone hole since before Smashmouth immortalised it in the lyrics for “All Star”—this disappearance is likely not due to the decrease in pollution around the world as we all stay indoors. “This Arctic ozone hole actually has nothing to do with coronavirus-related lockdowns,” CAMS explained repeatedly in the comments to the tweet. “It's been driven by an unusually strong and long-lived polar vortex, and isn't related to air quality changes.” Even in their statement a few weeks ago, the ESA had said they expected it to heal back by mid-April 2020.
The ozone layer is a layer of gas in the stratosphere that absorbs most of the sun’s harmful ultraviolet radiation—rays that are associated with skin cancer, cataracts, and a host of environmental issues. The infamous ozone holes occur because of the thinning of this layer of air—driven by extremely cold temperatures, sunlight, and substances such as chlorofluorocarbons (CFCs), which are common in products such as aerosol sprays, pesticides, and flame retardants. But the massive hole in question was bizarre in ways more than one. “While we are used to ozone holes developing over the Antarctic every year due to seasonal changes, the conditions needed for such strong ozone depletion are not normally found in the Northern Hemisphere,” said CAMS in their statement.
The holes in the Antarctic are mainly caused due to the migration of human-made chemicals such as CFCs into the stratosphere. These chemicals accumulate inside the polar vortex—a large area of cold air in the stratosphere over the poles—that develops over the Antarctic every winter. The polar vortex over the Arctic, however, is usually weaker than the Southern Hemisphere, so it is unusual for the Arctic to have ozone holes this huge.
According to recent data from NASA, ozone levels above the Arctic reached this record low after almost ten years—2011 was the last when this had happened. In fact, in October, the hole over Antarctica made news for shrinking to the smallest size ever on record. And though the hole that closed up might not have been because of long-term healing, CAMS believes there’s still hope. It tweeted: The ozone layer is also healing, but slowly.