Overview

• The UN’s World Meteorological Organization reports the Antarctic ozone hole was smaller in 2024 than in recent years, confirming a continued recovery trend.
• The 2024 peak occurred on 29 September with an ozone mass deficit of 46.1 million tonnes, below the 1990–2020 average, alongside generally higher global ozone columns.
• Officials attribute the long‑term improvement to the Montreal Protocol, which has cut production and consumption of most ozone‑depleting substances by more than 99%.
• Current UN assessments project a return to 1980‑like ozone levels by mid‑century, with timelines of about 2066 over the Antarctic, 2045 over the Arctic, and 2040 for most other regions.
• Scientists note that natural variability—such as El Niño, volcanic activity and high solar activity—shaped 2024 outcomes, and Copernicus reports the 2025 Antarctic hole developed earlier and spans about 15 million km² at the latest reading.