Ozone hole over Antarctica expands sharply

The likely cause has been identified.

In September, the ozone hole over Antarctica grew sharply and, according to scientists’ forecasts, is about to become even larger. Researchers suggest that the likely cause is a sudden drop in temperature.

This is stated in a report by the Copernicus Atmosphere Monitoring Service (CAMS). In addition, the average ozone level was below normal across a vast area stretching from Greenland and Europe to Central Asia, Japan, and Muscovy’s Kamchatka Peninsula.

“The development of the ozone hole over Antarctica can vary significantly from year to year, depending on a number of atmospheric and chemical factors. Although we observed a rapid increase in its area at the beginning of September this year, other indicators remain close to historical averages. These findings highlight the importance of monitoring the complex interaction between human impacts and natural factors. CAMS provides the high-quality data, forecasts, and analyses needed to understand the state of the ozone layer and track its long-term recovery,” said Laurence Rouil, director of the Copernicus Atmosphere Monitoring Service.

CAMS diagram of the ozone hole’s area as of September 12, 2026. The red line shows data for the current year, while the dashed red line is the forecast for the next 5 days. The thicker, darker blue line shows the development of the ozone hole throughout 2025. The lighter blue line represents 2024. The gray colors indicate the period from 1979 to 2023.

Researchers found that in August, the ozone hole developed at a rate typical of the previous 46 years, reaching an area of about 15 million square kilometers.

In the first half of September, this figure rose sharply, reaching 25 million square kilometers on Saturday, September 12.

This is approximately 5 million square kilometers more than the average for that period.

“Forecasts indicate a possible further increase in the area in mid-September. Ozone depletion in the stratosphere of the Southern Hemisphere occurs because low temperatures promote the formation of polar stratospheric clouds, which play a role in activating the chemical destruction of ozone by halogens in the presence of sunlight during the southern spring (from August to November),” CAMS reported.

It is worth recalling that the ozone hole reached a record size (29.6 million square kilometers) in September 2006. In recent years, it has been shrinking, indicating the partial recovery of the ozone layer.

The ozone layer is located in the stratosphere at an altitude of 15 to 50 kilometers above the Earth’s surface.

It can be called the planet’s natural “sunscreen.” Ozone is a molecule consisting of three oxygen atoms that occurs naturally in small quantities. Closer to the ground, ozone can also form as a result of photochemical reactions between sunlight and polluted air, creating harmful smog.

In the stratosphere, ozone serves as a “shield,” protecting the planet from potentially harmful ultraviolet radiation, which is the main cause of skin cancer.