GENEVA (AN) — Scientists say global efforts to fix the ozone hole over Antarctica are progressing as atmospheric abundances of tropospheric chlorine and bromine from long-lived ozone-depleting substances decline.
What's new: There's "growing evidence that the ozone layer is indeed on track to long-term recovery," the World Meteorological Organization said on Monday while issuing its WMO Ozone and UV Bulletin for World Ozone Day. "Given that some ozone-depleting substances also function as greenhouse gases, their phaseout is an added bonus for the climate."
What's next: Efforts to replace chloroflourocarbons used in refrigerators, air conditioners and foams must be monitored to avoid "complacency," the United Nations weather agency says. "Many factors will influence the expected recovery of ozone, which must be fully measured and understood," its Bulletin concludes. CFCs not only trap Earth’s heat, contributing to a rise in average surface temperatures, but they also destroy ozone, the atmospheric layer that protects against the sun’s most harmful rays.
“The ozone layer, once an ailing patient, is on the road to recovery,” said U.N. Secretary-General António Guterres. "Now, it’s time to go further." Guterres called for all nations to adopt the 1989 Montreal Protocol's 2019 Kigali Amendment – four-fifths have done so already – which requires a gradual reduction of hydrofluorocarbons, or HFCs.
What's important: When the Montreal Protocol was first signed, countries did not recognize that CFC users would turn to the cheapest available alternative, hydrochloroflourocarbons, or HCFCs, and their byproducts, HFCs. Both decompose faster than CFCs, because they contain hydrogen, but like the CFCs they are potent greenhouse gases – and can harm the climate up to 10,000 times worse than carbon dioxide emissions.
"If fully ratified and implemented, the Kigali Amendment could help avoid as much as 0.5° Celsius of global heating by the end of this century," Guterres said. "Yet, a range of climate solutions – including those related to refrigerants and energy efficiency – are also needed to avert a climate crisis by mid-century."
Who's involved: The Montreal Protocol, which includes all 193 U.N. member nations plus the Cook Islands, Holy See, Niue, Palestine, and European Union, is considered one of the most effective environmental treaties – and the first to be adopted by all countries.
More than US$3.6 billion has been spent through an affiliated fund to encourage nations to get rid of CFCs, eliminating 488,909 metric tons of ozone-damaging materials through 7,000 projects. Scientists blame CFCs for creating a seasonal hole in the stratospheric ozone layer between 15 and 30 kilometers over Antarctica, but expect it to heal by 2050. The Arctic also has suffered from ozone depletion, but its hole is generally smaller than the one over Antarctica.
"In 1987, as a global community, we decided to phase out ozone-depleting substances. The result? The ozone layer is on track to being fully restored by 2050!" says U.N. Climate Change. "Let's do the same for our climate."
What's happening now: The Bulletin explores how weather conditions and a major volcanic eruption impacted the Antarctic ozone hole in 2023. It also outlines measures to protect human health and the environment from damaging UV radiation.
