Environmental policy | Ozone layer continues to recover

The Earth's protective ozone layer is recovering, and the ozone hole continued to shrink last year, according to a new report presented by the World Meteorological Organization (WMO) in Geneva on Tuesday. While this is partly due to natural atmospheric factors that lead to annual fluctuations, the long-term positive trend reflects the success of joint international action, the report states.

Comment on the topic: It's possible after all – lessons can be learned from saving the ozone layer

The UN organization publishes an annual bulletin with current calculations on World Ozone Day on September 16. In 2025, it will coincide with the 40th anniversary of the entry into force of the Vienna Convention, which first recognized the depletion of the stratospheric ozone layer as a global problem. The subsequent Montreal Protocol established a binding ban on certain greenhouse gases such as CFCs and HFCs. This has been successful: To date, the production and consumption of these ozone-depleting substances, which were used in refrigerators, air conditioners, fire-fighting foam, and even deodorant and hairspray, have decreased by 99 percent. "The Vienna Convention and its Montreal Protocol became a milestone of multilateral success," said UN Secretary-General António Guterres. "Today, the ozone layer is recovering. This reminds us that progress is possible when nations heed the warnings of science."

Scientists had already sounded the alarm in 1975 that the ozone layer was being damaged by human activities, allowing more of the sun's dangerous UV radiation to reach Earth, increasing the risk of skin cancer, cataracts, and ecosystem damage. Meanwhile, according to WMO forecasts, the ozone layer is well on its way to recovering to 1980 levels (before the ozone hole appeared) by around 2066 over Antarctica, by 2045 over the Arctic, and by 2040 over the rest of the world. The largest ozone hole is traditionally found over Antarctica in spring. In 2024, its depth was below the 1990-2020 average, with a maximum ozone mass loss of 46.1 million tons. "The continued later onset has been identified as a clear sign of incipient recovery," the bulletin states.