WMO: 2025 ozone hole among the smallest in recent decades

The World Meteorological Organization (WMO) reported that the ozone hole in 2025 was one of the smallest observed in recent decades, citing both reduced area and shallower depth compared with past years.

The agency says 2025 marks the second consecutive year in which the size and depth of the ozone hole were significantly below the 1990–2010 average. Last year’s ozone hole was recorded as the fourth or fifth smallest since severe ozone depletion patterns were first noted in 1992.

WMO scientists point out that natural atmospheric variability contributes to annual fluctuations, but they single out the long-term decline in use of artificial ozone-depleting substances — notably chlorofluorocarbons (CFCs), commonly called freons — as a decisive factor in the recovery.

WMO Secretary‑General Celeste Saulo said: "The ozone layer has been recovering since 2000 and we can expect its full restoration within a few decades."

Rising UV and health concerns

Despite the recovery trend, the WMO warned that thinner ozone allows more harmful ultraviolet (UV) radiation to reach the surface. In parts of Europe, UV levels have risen by as much as 20 percent since the mid-1990s, the agency reported.

Ground-based measurements attribute much of that increase to reduced cloud cover and a longer annual duration of sunshine, which together raise the amount of solar radiation reaching people and ecosystems. Higher UV exposure increases the risk of skin damage, skin cancer and cataracts, prompting the WMO to urge targeted protective measures.

The report also highlighted the policy milestones behind the recovery: the Vienna Convention for the Protection of the Ozone Layer adopted in 1985 and the subsequent Montreal Protocol. According to the WMO, these measures led to the phased elimination of more than 99 percent of regulated ozone-depleting substances that were once used in refrigerators, air conditioners, fire‑extinguishing foams and hair sprays.

Photo: Printskrin/Iks