Ozone Hole Declines: 2025 Ranked Fifth Smallest Since 1992

In 2025, the Antarctic ozone hole was reported as the fifth smallest since 1992, marking a significant environmental achievement. According to NASA and NOAA, the ozone hole's size peaked on September 9, reaching 8.83 million square miles, which is about 30% smaller than the largest hole recorded in 2006.

The average extent of the ozone hole during its peak season from September 7 through October 13 was approximately 7.23 million square miles, indicating a trend toward smaller ozone holes compared to the early 2000s.

Paul Newman, a senior scientist at the University of Maryland and leader of NASA's ozone research team, noted that the hole this year would have been over one million square miles larger had chlorine levels in the stratosphere remained the same as they were 25 years ago.

The reduced size of the ozone hole is attributed to decades of global efforts to phase out ozone-depleting substances under the Montreal Protocol, which was established in 1992 and has since been amended to drive the gradual recovery of the ozone layer.

The Montreal Protocol led to significant reductions in chlorofluorocarbons and other harmful chemicals that were previously prevalent in products like aerosol sprays and refrigerants. Stephen Montzka, a senior scientist at NOAA's Global Monitoring Laboratory, remarked that the levels of ozone-depleting substances in the Antarctic stratosphere have declined by about a third since peaking around the year 2000.

Furthermore, natural factors such as temperature and atmospheric circulation play a role in ozone concentrations, with a weaker polar vortex noted in August likely contributing to the smaller ozone hole this year.

The ozone layer, positioned between seven and 31 miles above the Earth's surface, acts as a crucial barrier against harmful ultraviolet radiation. Increased UV exposure can lead to adverse effects such as crop damage and heightened risks of skin cancer and cataracts.

The ozone depletion process is initiated when man-made compounds containing chlorine and bromine reach the stratosphere, where they are broken down by UV radiation, leading to ozone molecule destruction.

Measuring the ozone levels is done using various satellites, including NASA's Aura satellite and NOAA's satellites, along with ground-based instruments. This year's lowest recorded ozone concentration was 147 Dobson Units, compared to the lowest level ever recorded at the South Pole, which was 92 Dobson Units in October 2006.

While the 2025 ozone hole ranks as the fifth smallest since 1992, it ranks 14th smallest over the 46 years of satellite observations beginning in 1979. The projections suggest that the ozone hole is on a path to recovery, with expectations for it to fully recover by the late 2060s as legacy emissions from banned substances continue to diminish.