The ozone layer is gradually healing and is expected to recover by 2066, according to a recent report by scientists from the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA). Scientists noted that during 2024’s peak depletion season, the ozone hole’s size was the seventh smallest since 1992.
The ozone layer is estimated to be 15 to 35 kilometers above the earth’s surface and is highly concentrated with a colorless but reactive and unstable ozone gas. It is known as the protective shield of the Earth, keeping UV radiation away, which poses health risks to humans and animals and damages plants.
A 20-million-square-km hole as a reason for optimism?
Yearly, a hole opens up in the ozone layer above the southern pole of the Earth which includes the Antarctic region, during the peak season of the ozone layer’s depletion. But during 2024’s peak depletion season from September 7 to October 13, scientists noted that the ozone hole’s size was the seventh smallest since the recovery began in 1992.
This year nearly 20 million square kilometers was the monthly average of ozone depletion in the Antarctic region, which was almost three times the size of the adjoining United States. As of September 2023, the hole exceeded 26 million square kilometers.
According to Paul Newman of NASA’s ozone research team, the 2024 Antarctic ozone hole was smaller than those of the early 2000s. He attributes the gradual recovery over the past two decades to international efforts to minimize ozone-depleting substances (ODS) in the atmosphere.
Causes and countermeasures
ODS are hydrochlorofluorocarbons (HCFCs) which are gases globally utilized in refrigeration, spray cans, air conditioning, and foam manufacturing. When released, they break down the ozone layer molecules in the upper atmosphere. HCFCs were replaced with hydrofluorocarbons (HFCs) which cause less harm to the ozone layer and this has apparently helped it to recover albeit slowly.
NASA scientists are optimistic about the ozone hole recovering by 2066 although that may be hindered by the long lifespan of ODS hovering in the atmosphere. Even if the heavily populated and industrial eastern China releases ODS in the short term, that will not delay the recovery of the ozone layer, the scientists added. 94% of the Chinese population lives in the eastern region and occupies 43% of the country’s land area.
Speaking in January 2023, World Meteorological Organization Secretary-General, Petteri Taalas, said:
“Success in phasing out ozone-eating chemicals shows us what can and must be done – as a matter of urgency – to transition away from fossil fuels, reduce greenhouse gases and so limit temperature increase”.
Since complying with the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer can be an economic burden to developing countries, the Multilateral Fund for the Implementation of the Montreal Protocol was set up to assist them. As of May 2023, contributions to this fund had reached almost US$5.1 billion, and 144 developing countries had been assisted in complying. This money helps such countries to speed up the phasing out of ODS still used by industries there.
Why does ozone layer recovery matter?
The ozone layer protects humans from radiation caused by the sun’s ultraviolet rays, which can cause sunburn, glaucoma, or skin cancer. Also, if the Earth receives high levels of ultraviolet rays, they can cause death in human, animal, and plant life, hence causing food insecurity.
According to UNEP ozone reports, from 1987 to 2060 the Montreal Protocol will globally yield about US$1.8 trillion in health benefits, and nearly US$460 billion estimated worth of damage will be avoided in fisheries, agriculture, and materials.
Although there are positive strides in the recovery of the ozone layer through the Montreal Protocol, there are also climate change-related challenges that remain, Megumi Seki, the executive secretary of the Ozone Secretariat at UNEP said in a September 2022 UNEP interview.
“It’s very difficult to talk about complete recovery because the atmosphere itself is very different to what it was when there was no ozone depletion. Greenhouse gases, temperature changes and global warming all affect the dynamics and chemical processes in the atmosphere, impacting the recovery process. In other parts of the stratosphere, the ozone layer recovery is expected to be earlier,” she said.
