Details of the study

While we thought the huge hole in Antarctica’s ozone layer was gradually closing, it gradually grew larger. After analyzing monthly and daily changes in ozone from 2004 to 2022, researchers found that there is significantly less ozone in the ozone hole than there was 19 years ago, with levels dropping a shocking 26 percent.

Our analysis ended with data for 2022, but as of today the 2023 ozone hole has already exceeded the size of the ozone hole three years ago; By the end of last month it was more than 26 million square kilometers, nearly twice as large. Antarctica.
– said the study’s lead author, Hanna Kessenich from the University of Otago.

Located in the stratosphere, miles above the surface, the ozone layer is vital to life on Earth, protecting our planet from the Sun’s harsh ultraviolet radiation. To protect this, world leaders at the United Nations adopted the historic Montreal Protocol in 1987, which internationally banned chlorofluorocarbons (CFCs) used in refrigerators and aerosols. As scientists discovered several years ago, these chemical compounds destroy ozone.

The agreement was widely hailed as a major environmental victory. A recent UN report even predicted that the ozone layer will return to 1980s levels by 2040.

But Hanna Kessenich and her team argue that we are celebrating too early. He says much of the news we’ve heard about the ozone layer over the past few years has left the public with the impression that “the ozone problem” has been solved. While the Montreal Protocol has greatly improved our situation with the destruction of the ozone layer by CFCs, this new hole is one of the largest in recent years.

What could be other reasons?

So the CFC ban worked, but they may not be the only ones to blame if we are to explain this latest expansion. Researchers suggest that ozone depletion may also be caused by the Antarctic polar vortex, a low-pressure vortex formed by cold westerly winds. So far they have noticed a connection between changes in the vortex and ozone depletion, but they cannot explain why this happens and what the connection is.

Other thoughts

Some of the researchers’ colleagues dispute the findings. Martin Uecker, from the Climate Change Research Center at the University of New South Wales, notes that existing literature has already established that these holes are caused by climate events such as bushfires and major volcanic eruptions in 2019. “It is important to note that the ozone hole is extremely variable from year to year, meaning it may be large one year and small the next., – Yuker wrote in response to the article. – A trend can only be detected over a longer period of time”. He also points out that the study “only used 22 years of data.”