The United Nations weather agency reports promising news regarding the recovery of the ozone layer.
The World Meteorological Organization (WMO) has released its annual Ozone and UV Bulletin, which analyzes the effects of significant volcanic eruptions and weather conditions on the Antarctic ozone hole in 2023. The report provides increasing evidence that the ozone layer is on a positive trajectory for long-term recovery.
Data from the research indicates that ozone loss during October and November 2023 was noticeably lower compared to 2022. The study explains that the significant eruption of the Hunga Tonga-Hunga Ha’apai volcano on January 15, 2022, resulted in increased water vapor in the stratosphere. However, this additional water vapor has only had a minor effect on the rate of ozone depletion in the lower Antarctic stratosphere, a process primarily driven by sunlight and specific chemicals.
Nevertheless, the excess water vapor has contributed to heightened depletion in the middle and upper stratospheric layers, particularly near the Antarctic stratospheric vortex’s edge. The eruption also caused alterations in ozone transport.
In the southern hemisphere, the year 2023 marked a return to higher mid-latitude ozone levels, ending several years of low total ozone columns, a situation exacerbated by significant wildfires in Australia in 2020 and 2021, as well as changes in ozone transport caused by the volcanic eruption’s water vapor.
According to the research, the eruption’s gases reached altitudes of up to 55 kilometers and, within just one week, led to a 5% reduction in the ozone layer over the tropical southwestern Pacific and Indian Ocean regions.
Furthermore, the WMO report noted that between January and July 2023, total ozone levels over Antarctica were below average, which facilitated the early identification of the ozone hole based on standard detection methods. These low initial levels affected total ozone column levels during the Antarctic spring, potentially linked to the eruption’s accelerated mid-latitude stratospheric ozone depletion.
Despite these challenges, there is optimism. The research suggests that if current measures continue to be upheld, the ozone layer is expected to return to 1980 levels—prior to the formation of the ozone hole—by 2066 for Antarctica, 2045 for the Arctic, and 2040 for the global average.