The Earth’s protective ozone layer is regenerating thanks to scientific efforts, and the ozone hole was smaller in 2024 than in recent years, the World Meteorological Organization (WMO) said Tuesday.
The WMO’s Ozone Bulletin noted that the relatively low level of ozone depletion observed in 2024 was partly due to natural atmospheric factors causing annual fluctuations, but highlighted that the long-term positive trend “reflects the success of coordinated international action.”
The report was released to mark World Ozone Day, observed each year on Sept. 16, and the 40th anniversary of the Vienna Convention, which recognized stratospheric ozone depletion as a global problem and established a framework for international cooperation in ozone research, systematic monitoring, and scientific assessment.
The theme of this year’s World Ozone Day, “From Science to Global Action,” echoes the WMO’s 75th anniversary slogan, “Science for Action,” said WMO Secretary-General Celeste Saulo, noting that the organization’s scientific work on the ozone layer “spans several decades” and relies on trust, international collaboration, and open data sharing.
UN Secretary-General Antonio Guterres added: “Forty years ago, nations came together to take the first step in protecting the ozone layer – guided by science, united in action.” He described the Vienna Convention and its Montreal Protocol as “a landmark of multilateral success..”
“Today, the ozone layer is healing. This achievement reminds us that when nations heed the warnings of science, progress is possible,” Guterres said.
To date, the Montreal Protocol has enabled the phase-out of more than 99% of the production and consumption of ozone-depleting substances used in refrigeration, air conditioning, firefighting foams, and even hair sprays.
As a result, the ozone layer is on track to return to 1980s levels by mid-century, significantly reducing risks of skin cancer, cataracts, and ecosystem damage from excessive UV exposure, the UN said.
