Large ozone hole detected over Antarctica: Is it a matter of concern?

Subject: Environment

Section: Climate Change

Context:

Satellite measurements over Antarctica have detected a giant hole in the ozone layer.

Details:

Ozone hole is detected by the European Space Agency Copernicus Sentinel-5P satellite under the EU’s environmental programme.
The hole, called the “ozone-depleted area” was 26 million square kilometers (10 million square miles) in size, roughly three times the size of Brazil.
The satellite measured trace gasses in the atmosphere in order to monitor the ozone and climate. It showed that this year’s ozone hole started earlier than usual, and had a big extension.
Experts believe the hole in the ozone is not likely to increase warming on the surface of Antarctica.

Ozone holes grow and shrink every year:

The ozone layer is a trace gas in the stratosphere, one of the four layers of the Earth’s atmosphere.
It functions as a protective gas shield that absorbs ultraviolet radiation, protecting humans and ecosystems from dangerous amounts of UV.
The size of the ozone hole over Antarctica fluctuates each year, opening each year in August and closing again in November or December.

Why is the ozone hole formed?

The ozone hole opens up because of the rotation of the Earth causing special winds over the closed landmass of Antarctica.
The winds create a mini climate, creating a shield over Antarctica preventing it from mixing with surrounding air. When the winds die down, the hole closes.

What caused the giant ozone hole this year?

It could be due to the volcanic eruptions at Hunga Tongain Tonga during December 2022 and January 2023.
Under normal conditions, gas released from a volcanic eruption stays below the level of the stratosphere, but this eruption sent a lot of water vapor into the stratosphere.
The water had an impact on the ozone layer through chemical reactions and changed its heating rate. The water vapor also contained other elements that can deplete ozone like bromine and iodine.

Human-caused ozone holes:

Human activities were creating huge ozone holes in the 1970s.
Ground and satellite-based measurements detected the holes, which were caused by widespread use of chemicals called chlorofluorocarbons.
One of the factors for ozone hole creation is the propellants we use as gasses to propel the solutions inside. These gaseous propellants contain chlorine, which is released high in the stratosphere and depletes the ozone.

Protection of ozone layer:

The 1985 Vienna Convention for the Protection of the Ozone Layer was an international agreement in which United Nations members recognized the fundamental importance of preventing damage to the stratospheric ozone layer.
In 1987,TheMontreal Protocol was created to protect the ozone layer by phasing out the production of these harmful substances.
The protocol was effective as the ozone holes got smaller in the decades after ozone-depleting gas emissions were controlled.

Is climate change reopening ozone holes?

Ozone depletion is not a principal cause of global climate change.
There are signs that rising global temperatures could be having an impact on ozone holes.
- The 2020 ozone hole opening was attributed to the wildfires of Australia.
- In 2021 it was due to the boreal forest fires.

Source: IE