The hole in the ozone layer over the Antarctic is one of the largest and deepest in recent years, according to new data.
The World Meteorological Organization has announced that the ozone hole above Antarctica grew rapidly from mid-August and peaked at around 24 million square kilometers (over 9.2 million square miles) in early October – that’s an area larger than Russia. Along with the help of the Copernicus Atmospheric Monitoring Service, NASA, Environment and Climate Change Canada, they currently estimate the hole covers 23 million square kilometers (8.8 million square miles), a higher than the average area over the last decade.
But fear not, this is not necessarily a symptom of the environmental doom facing our planet. The large ozone hole has been driven by a strong cold polar vortex and will not be a permanent state. The ozone hole naturally fluctuates in size each year, reaching a maximum between mid-September to mid-October, and is likely to return to normal by the end of the year. In fact, last year, scientists reported that the hole in the ozone layer over the Antarctic is the smallest its been in decades.
“There is much variability in how far ozone hole events develop each year. The 2020 ozone hole resembles the one from 2018, which also was a quite large hole, and is definitely in the upper part of the pack of the last fifteen years or so,” Vincent-Henri Peuch, director of Copernicus Atmosphere Monitoring Service at ECMWF, said in a statement
“With the sunlight returning to the South Pole in the last weeks, we saw continued ozone depletion over the area. After the unusually small and short-lived ozone hole in 2019, which was driven by special meteorological conditions, we are registering a rather large one again this year, which confirms that we need to continue enforcing the Montreal Protocol banning emissions of ozone-depleting chemicals,” Peuch explained.
The ozone layer is a region of the stratosphere between 15 and 30 kilometers (9.3 to 18.6 miles) above Earth's surface that has a high concentration of the gas ozone compared to other parts of the atmosphere. It effectively acts as a shield for our plant, absorbing much of the Sun's harmful ultraviolet rays. It's clear that human-made chemicals, namely refrigerants and solvents, can act as ozone-depleting substances after they are wafted up into the stratosphere.
It is also closely related to the temperature in the stratosphere, which appears to explain this blip. A recent polar vortex has kept this layer of Earth's atmosphere extremely chilly, allowing the formation of polar stratospheric clouds, which can only form at temperatures below -78°C (-108°F). These high-altitude clouds help to increase the chemical reactions involving the human-made chemicals that lead to ozone depletion, thereby further diminishing the ozone layer.
Concerns over the hole in the ozone layer became one of the biggest environmental worries of recent times when researchers discovered a hole in the layer above the South Pole in the 1970s and 1980s. It transpired that the layer was being worn away by human-made chemicals, namely refrigerants and solvents, that can act as ozone-depleting substances after they are wafted up into the stratosphere.
Fortunately, the world decided to take swift and decisive action. The Montreal Protocol, finalized in 1987, saw a global agreement to protect the ozone layer through the phase-out of ozone-depleting substances. This remains one of the most successful calls for global action ever achieved and is, to date, the only UN treaty that’s been ratified by every member state.