The Earth’s protective ozone layer is on the mend and could fully recover within the coming decades, the United Nations said Tuesday, praising the success of coordinated global action.
A new report by the UN’s World Meteorological Organization (WMO) revealed that the ozone hole over Antarctica in 2024 was smaller compared to recent years, calling it “encouraging scientific news for both human and planetary health.”
“Today, the ozone layer is healing,” UN Secretary-General Antonio Guterres said. “This milestone shows us that when nations listen to science, real progress is possible.”
The WMO’s Ozone Bulletin 2024 noted that the recent decline in depletion was partly linked to natural atmospheric variations that fluctuate year by year.
However, it stressed that the long-term improvement is largely the result of sustained international efforts.
The bulletin coincided with World Ozone Day and marked 40 years since the Vienna Convention, the first global treaty to recognize ozone depletion as a serious threat.
That 1975 agreement paved the way for the landmark Montreal Protocol of 1987, which targeted the phase-out of harmful ozone-depleting chemicals used in refrigeration, air conditioning, and aerosol sprays.
According to the WMO, the Montreal Protocol has already eliminated over 99 percent of the production and consumption of controlled ozone-depleting substances.
“As a result, the ozone layer is now on track to return to 1980s levels by mid-century significantly lowering the risks of skin cancer, cataracts, and damage to ecosystems caused by excessive ultraviolet radiation,” the WMO said.
The bulletin determined that the depth of the ozone hole, which appears over the Antarctic every spring, had a maximum ozone mass deficit of 46.1 million tonnes on September 29 last year below the 1990-2020 average.
WMO highlighted a relatively slow onset, with delayed ozone depletion observed through the month of September, followed by a relatively rapid recovery after the maximum deficit was reached.
“This persistent later onset has been identified as a robust indication of initial recovery of the Antarctic ozone hole,” the bulletin said.
The WMO and the UN Environment Programme co-sponsor a scientific assessment of ozone depletion every four years.
The most recent assessment in 2022 indicated that, if current policies remain in place, the ozone layer should recover to 1980 values before the hole appeared by around 2066 over the Antarctic, by 2045 over the Arctic, and by 2040 for the rest of the world.
