In a recent study conducted by scientists from the University of Otago, it has been discovered that the ozone hole over Antarctica is more extensive and enduring than previously believed. The study, published in Nature Communications, analyzed monthly and daily changes in ozone concentration from 2004 to 2022. The results indicate that the ozone hole not only increases in size but also deepens for a significant part of the spring.

The lead author of the study, Hannah Kessenich, highlights that the ozone decline may result from changes in the air entering the polar vortex over Antarctica. This suggests that recent large ozone holes may not be solely caused by chlorofluorocarbons (CFCs), which were previously considered the primary cause of their formation.

The Montreal Protocol of 1987, aimed at regulating the production and consumption of ozone-depleting substances, has brought some improvements concerning CFCs. However, despite these efforts, the ozone hole in recent years has been one of the largest in history. By 2023, its size had already exceeded 26 million square kilometers, almost twice the surface area of Antarctica. Yet, questions about the relevance of combating freons seem to remain unasked, even though their significance is self-evident.

The ozone hole has a significant impact on the climate of the southern hemisphere. It not only causes extreme levels of ultraviolet radiation on the surface of Antarctica but also influences the distribution of heat in the atmosphere, leading to changes in wind patterns and surface climate. These changes can have a local impact on regions such as Australia and New Zealand, as evidenced by recent bushfires and cyclones.

However, Kessenich reassures the residents of New Zealand, stating that they do not need to worry about increased ultraviolet radiation because the ozone hole is mainly located directly over Antarctica and the South Pole.

This study sheds new light on the complex factors contributing to the persistence of the ozone hole and underscores the importance of continuous research to better understand the impact of ozone layer depletion on the climate of the southern hemisphere and its potential influence on local regions.