First Ozone Layer Depletion Did Not Start in Antarctica, But in the Tropics in the 1950s

A new and comprehensive study published in the journal Proceedings of the National Academy of Sciences (PNAS) is rewriting the long-held classical views on the thinning of the ozone layer worldwide and the origin of the famous 'ozone hole' phenomenon. This research, the details of which were also shared by National Geographic, claims that the damage to the ozone layer did not begin over Antarctica as previous modeling suggested, and that chlorofluorocarbons (CFCs) were not the only ones responsible. By analyzing decades of atmospheric observations and historical data, scientists revealed that the damage actually started much earlier and in different parts of the world, particularly in the tropical stratospheric layers.

A team led by scientist Susan Solomon, an authority on the subject in the scientific world, scrutinized changes in the upper atmosphere and the impacts of industrial chemicals in their detailed examinations. Based on traces in samples obtained from ice cores and inductive measurements, the research team determined that the weakening of the ozone layer was actually observed in tropical regions in the early 1950s. In this period, it was proven that compounds with the potential to destroy the ozone layer caused an imbalanced disruption in the atmosphere long before causing a major collapse over Antarctica.

One of the most striking findings of the study is that 'carbon tetrachloride', used frequently in industry in the 20th century as a common solvent, is primarily responsible for this early period depletion. This harmful substance had created a visible and negative impact in the atmosphere before the widespread use of CFCs globally and the large-scale effects they created. High-resolution climate models show that the damage caused by such substances initiated a gradual reduction process in the global atmosphere long before the seasonal crisis in Antarctica.

The scientific view supported by international institutions such as the National Aeronautics and Space Administration (NASA), the National Oceanic and Atmospheric Administration (NOAA), and the World Meteorological Organization (WMO) is that the ozone hole is a seasonal event and stems mainly from Antarctica's extreme cold conditions and atmospheric dynamics. Satellite observations and in situ measurements made since the 1980s confirm that human-made chlorine is directly linked to the process of destroying the ozone layer, and these findings form the basis of environmental agreements like the Montreal Protocol.

However, this new research adds a new dimension to scientific knowledge by further detailing and deepening the current scientific framework rather than invalidating the Montreal Protocol. Susan Solomon and her team state that they are rewriting the history of the ozone layer's weakening by clarifying the contribution of other chemicals like carbon tetrachloride at the very beginning of the process, without changing the fact that CFCs are the main factor. This does not mean the current explanation is wrong, but shows that the complexity of environmental events is better understood in the light of the development of science and new data, and that early effects cannot be dismissed.