Antarctic Ozone Hole Expands Sharply in Early September

The ozone hole over Antarctica has experienced a significant expansion in early September, according to analysis from the Copernicus Atmosphere Monitoring Service (CAMS). Scientists observed a sharp increase in the hole's area, which is now larger than typically seen at this time of year and is projected to grow further.

In August, the ozone hole was developing at a typical rate, covering an area of approximately 5.79 million square miles (15 million square kilometers). However, by September 12, the area had surged to 9.6 million square miles (25 million square kilometers), which is about 1.9 million square miles (five million square kilometers) above the average for this period.

Laurence Rouil, Director of CAMS, stated that these findings underscore the importance of monitoring the complex interplay between human-caused disturbances and natural factors affecting the ozone layer. He noted that while the hole's area has increased rapidly in early September, other indicators remain close to historical averages.

The ozone layer, situated in the stratosphere approximately 7 to 25 miles above Earth's surface, acts as a vital shield, absorbing much of the sun's harmful ultraviolet radiation. Human emissions over the past half-century have led to its thinning, most notably over the Antarctic, where a hole characteristically reopens each austral spring (September to November).

While the record for the largest ozone hole was set in the late 1970s at 11.42 million square miles (29.6 million square kilometers), recent years have shown smaller and shorter-lived holes, suggesting a potential recovery. The current expansion is attributed by researchers to a sudden decrease in stratospheric temperatures. Colder weather facilitates the formation of polar stratospheric clouds, which play a role in the chemical destruction of ozone in the presence of sunlight and halogens.

This development follows CAMS' confirmation that August 2026 was the warmest month on record globally, with an average temperature of 16.96°C (62.52°F). This period also saw record-high average sea surface temperatures, indicating a strengthening El Niño. Samantha Burgess, Strategic Lead for Climate at the European Centre for Medium-Range Weather Forecasts (ECMWF), highlighted that these conditions demonstrate how climate change is driving extreme weather patterns across the atmosphere and oceans.