A new study confirms that the Antarctic ozone layer is healing due to global efforts to reduce ozone-depleting substances, with a significant decrease in CFCs being the main cause.
A new study led by researchers from MIT has confirmed that the Antarctic ozone layer is healing due to global efforts to reduce ozone-depleting substances. ‘The recovery of the ozone hole is mainly attributed to the decrease in chlorofluorocarbons (CFCs) and other ozone-depleting substances.’ The study, published in the journal Nature, found that with 95% confidence, the recovery of the ozone hole is mainly attributed to the decrease in CFCs and other ozone-depleting substances.
CFC emissions refer to the release of chlorofluorocarbons, a type of greenhouse gas that contributes to ozone depletion and climate change.
Historically, CFCs were widely used as refrigerants in air conditioning and refrigeration systems, propellants in aerosol cans, and solvents in industrial processes.
According to the 'United Nations Environment Programme' (UNEP), the production of CFCs peaked in 1988, with over 1 million metric tons released annually.
The 'Montreal Protocol', an international agreement signed in 1987, aimed to phase out CFCs by reducing their production and consumption.
The Cause of Ozone Recovery
In the past, scientists have observed signs of ozone recovery in the Antarctic. However, this new study is the first to quantify confidence in the recovery of the ozone hole. The researchers used a method called ‘fingerprinting,’ which was pioneered by Klaus Hasselmann, who was awarded the Nobel Prize in Physics in 2021 for the technique. This approach isolates the influence of specific climate factors, apart from natural, meteorological noise.
Anthropogenic Healing
The MIT team applied the fingerprinting method to identify the effect of human reductions in ozone-depleting substances on the recovery of the ozone hole. They ran simulations of the Earth’s atmosphere under different starting conditions and compared these simulations to actual satellite observations of the Antarctic ozone hole from 2005 to the present day.
A Clear Signal
The team found that, over time, a clear signal of ozone recovery emerged in the observations, confirming that the decrease in CFCs is the main cause of the healing ozone layer. In 2018, the signal was at its strongest, and the team could say with 95% confidence that ozone recovery was due mainly to reductions in ozone-depleting substances.
The Montreal Protocol, signed in 1987, aimed to reduce ozone-depleting substances.
As a result, the concentration of chlorofluorocarbons (CFCs) decreased by 10% annually.
By 1998, CFC production had ceased, and the ozone layer began to recover.
According to NASA, the Antarctic ozone hole has shrunk by 20% since its peak in 2000.
The recovery is attributed to a combination of reduced emissions and natural atmospheric processes.
A Promising Future
If the trend continues, and the fingerprint of ozone recovery grows stronger, Solomon anticipates that soon there will be a year when the ozone layer stays entirely intact. Eventually, the ozone hole should stay shut for good. ‘By something like 2035, we might see a year when there’s no ozone hole depletion at all in the Antarctic,’ she says.
Supporting Research
This research was supported, in part, by the National Science Foundation and NASA. The study highlights the importance of international cooperation and agreements to reduce emissions and protect the environment.
