Overview

• The WMO’s 2024 Ozone Bulletin reports the Antarctic ozone hole peaked at a maximum ozone mass deficit of 46.1 million tonnes on September 29, smaller than the unusually large holes from 2020 to 2023 and below the 1990–2020 average.
• The 2024 season saw a delayed onset of depletion followed by rapid recovery, a pattern cited as a robust early sign of Antarctic improvement within year-to-year natural variability.
• Global stratospheric ozone levels were higher in 2024 than in recent years, with the bulletin linking part of the improvement to atmospheric factors such as El Niño and solar activity.
• Long-term projections remain unchanged: recovery to 1980 values is expected around 2040 for most latitudes, by 2045 over the Arctic, and by 2066 over Antarctica if current policies hold.
• The Montreal Protocol has phased out over 99% of controlled ozone‑depleting substances, and experts call for continued surveillance of ozone, ODS replacements, and adequate funding for ground stations and satellites, with Kigali-driven HFC cuts offering added climate benefits.