Ozone Hole Smallest in Six Years, Confirming Long-Term Recovery Trend

The World Meteorological Organization announced in December 2025 that the ozone hole over Antarctica was its smallest and shortest-lived in six years, confirming a long-term recovery trend. This continues a pattern where the annually variable hole is steadily closing up — entirely the result of the Montreal Protocol, the 1987 international treaty that banned ozone-depleting chemicals.

The ozone layer protects life on Earth from harmful ultraviolet radiation. Its recovery is one of the greatest success stories of international environmental cooperation, proving that when nations act together on scientific evidence, they can reverse planetary-scale damage.

“This continues a pattern where the annually variable hole is steadily closing up — entirely the result of the Montreal Protocol, the 1987 international treaty that banned ozone-depleting chemicals.”

"The 2025 ozone hole data provides further encouraging evidence that the Montreal Protocol is working," said WMO scientists. The full recovery of the ozone layer is expected by around 2066 over Antarctica.