The World Meteorological Organization (WMO) Ozone & UV Bulletin No. 3 (Sept 2025) reports that stratospheric ozone levels in 2024 were above the long-term global averages over much of the Northern Hemisphere, particularly in Arctic spring, where total ozone columns were observed to be ~14% higher than the 1960–2023 average. These elevated ozone levels led to a decrease in Northern Hemisphere UV radiation at the surface by about 5% during summer months. At Antarctica, the 2024 ozone hole was shallower than recent years, with a delayed onset of depletion and faster recovery, signaling early signs of ozone layer healing under the Montreal Protocol.
However, the Bulletin emphasizes that recovery is not uniform—some tropical regions saw negative anomalies (lower ozone levels), and many of the gains are sensitive to atmospheric transport, solar variability, and greenhouse gas interactions. The report also highlights issues around the durability and calibration of monitoring instruments, the need to update and expand UV/radiation measurement networks, especially in under-monitored regions, and risks to human health from intermittent increases in UV exposure.
This data underlines that international environmental treaties like the Montreal Protocol and its amendments remain crucial and effective but vigilance is needed. For policy in India, this means strengthening ozone layer protection commitments, expanding ground and satellite‐based monitoring, and integrating UV exposure risk into public health guidelines (skin cancer, eye damage). Additionally, it suggests investing in instruments and networks to ensure quality, calibration, and coverage, particularly in tropical and high UV regions where risks may be under-documented.
Relevant Question for Policy Stakeholders:
What steps should India take to ensure consistent, high-quality ozone and UV monitoring, and how can those data feed into public health policies to mitigate UV-related risks (especially in tropical zones)?
Follow the full bulletin here:
https://wmo.int/sites/default/files/2025-09/Ozone-and-UV-Bulletin_3_en_0.pdf
