But holes in the ozone layer are shrinking thanks to decades of global efforts to repair it, the World Meteorological Organization (WMO) confirmed yesterday.
Scientists first discovered a void over Antarctica in 1985. A few years later, countries around the world adopted the Montreal Protocol, a global effort to phase out “ozone-depleting substances.” And now, thanks to this study, scientists expect the ozone layer to look like its normal, healthy state for years to come. This is an advance that will reduce the risk of skin cancer and cataracts in humans, as well as sun damage to plants and crops.
WMO thinks that around 2066, the ozone layer will return to what it was over Antarctica in 1980. Other areas are expected to recover even more quickly, as ozone depletion is most severe here. Above the Arctic, the ozone layer will appear in 2045 as it did in 1980. For the rest of the world, this improvement is expected to occur by 2040. A panel of United Nations experts presented these findings yesterday at the annual meeting of the American Meteorological Society. Of course, this progress depends on policies that limit ozone-depleting substances.
The apocalypse scenario has been postponed for now! We survived at the last minute!
Ozone molecules in the stratosphere absorb harmful UV-B radiation from the sun, preventing most of it from reaching us. It’s part of the continuous process of creating and destroying ozone in our atmosphere. However, when certain chemicals rise, this balance is disturbed and causes more ozone to be destroyed than is created.
Some of the worst offenders are chlorofluorocarbons (CFCs), once used in refrigeration, air conditioning, aerosol sprays, and a number of other products, and hydrochlorofluorocarbons (HCFCs), which were developed as less harmful substitutes for CFCs. Fortunately, so far, the Montreal Protocol has managed to phase out about 99% of ozone-depleting substances.
The global agreement to protect the ozone layer is also beneficial for efforts to slow climate change. Substances that deplete the ozone layer have been replaced by another class of chemicals, called HFCs, with strong greenhouse gas emissions. The Kigali Agreement was added to the Montreal Agreement in 2016 to limit chemicals that warm the planet. Undermining HFCs globally is expected to significantly reduce global warming – by half a degree Celsius by 2100. In terms of context, the world has already warmed by about 1.2 degrees Celsius since the pre-industrial era, which exacerbates many of the extreme weather events we experience today.
But there’s a climate warning about the WMO’s good news. The expert panel warns that “geoengineering” that deliberately manipulates the climate and atmosphere to undo some of the damage we do by burning fossil fuels could potentially pay for itself in the ozone layer. Proponents think this tactic could help cool the planet because aerosols can reflect some of the sunlight back into space. However, according to a recent WMO-sponsored report, these “carry significant risks and can have unintended consequences”. And some climate experts have already sounded the alarm bells about an initiative’s recent attempt to release reflective sulfur particles in the stratosphere.