Causes of ozone layer depletion
The Earth’s atmosphere composed of different layers. The troposphere is the lowest layer of Earth’s atmosphere where all the human activities happen. The next layer in Earth’s atmosphere is the stratosphere. Most commercial airplane activities occur in the lower layer of the stratosphere.
Most of the atmospheric ozone also concentrates on the lower layer of the stratosphere. Ozone contains three oxygen molecules. These ozone molecules create an ozone layer in the stratosphere. The ozone layer absorbs radiation from the Sun and prevents it from reaching the Earth’s surface. In short, the ozone layer absorbs the harmful ultraviolet radiation from the Sun that may cause various adverse effects to living organisms on the planet.
The ozone layer acts as a protective shield that protects us from hazardous UV radiation. Unfortunately, this protective shield is depleting due to various reasons; most of them are human-made reasons. There are multiple causes of ozone depletion which we are going to discuss below. Before that, it is imperative to understand what ozone depletion is –
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What is ozone depletion?
In simple terms, the reduction of the ozone concentration in the stratosphere is known as ozone layer depletion. The primary substance that disturbs the ozone concentration is CFCs i.e., chlorofluorocarbon. The depletion of the ozone layer starts when CFCs enter into the stratosphere layer of Earth’s atmosphere.
CFCs cause a considerable amount of break down in the ozone layer reacting with the ozone molecule. The depletion of ozone was started majorly from the age of industrialization. The gradual reduction in ozone concentration is causing mainly due to harmful emissions from different industries. Here you can go through the major causes of the ozone layer hole to find out the possible solutions for this big environmental issue.
What are the main Ozone Depleting Substances (ODS)?
Ozone layer depletion is caused by CFCs, HCFCs, Halogens, Carbon Tetrachloride, Methyl Chloroform. All these depleting substances are explained below –
Mainly used in cooling appliances such as refrigerators, air conditioners. Also used in dry cleaning agents, industrial solvents, hospital sterilizers, foaming products like mattresses, cushions, etc.
HCFCs also get its way into the atmosphere through various human activities like vehicles and many other industrial emissions, etc.
Halogens are used in specific fire extinguishers and also affect the ozone molecule present in the atmosphere.
- Carbon Tetrachloride
Carbon tetrachloride is also used in some specific extinguishers and solvents.
- Methyl Chloroform
Methyl chloroform is widely used in different industries such as vapor degreasing, adhesives & some aerosols, cold cleaning, chemical processing, etc.
What Causes Ozone Depletion?
The following points are quite enough to explain the reasons for ozone layer depletion.
- Emission of CFCs (Chlorofluorocarbons)
The triatomic form of oxygen found in Earth’s atmosphere is termed as O3 i.e., ozone. CFCs are one of the major causes of ozone layer depletion. The CFC emissions are on the top in causing the ozone layer hole (approximately up to 80% of the entire ozone depletion).
The primary reasons that provoke ozone depletion include lower temperature, higher concentration of chlorine & bromine in the upper layer of the stratosphere.
The primary sources of CFC emissions are soaps, insulating foams, solvents, spray aerosols, take-away containers, cooling equipment like refrigerator & ACs, etc. All these use chlorofluorocarbons. The use of these products causes accumulations of a vast amount of CFC in the atmospheric layers of Earth. When the CFCs enter the stratosphere layer, it starts affecting the ozone layer.
The CFC molecules start breaking into chlorine atoms through ultraviolet radiation. When these chlorine atoms react with an ozone molecule, it affects the entire chemical cycle of the ozone layer. As a result, it causes a hole in the ozone layer.
- Emission of HCFCs (Hydrochlorofluorocarbons) and VOCs (Volatile Organic Compounds)
Emission of HCFCs and VOCs are also the vital causes of the ozone layer hole. HCFCs, VOC, and other ozone-depleting substances (ODS) are quite common to be emitted through various human activities. These activities include the use of vehicles, emission from industries and factories, refrigerators, aerosols, etc.
These ozone-depleting substances are comparatively stable in the lower layers of Earth’s atmosphere. On the other hand, when it reaches the stratosphere layer of Earth’s atmosphere, it gets exposed to UV radiation, where it breaks down and releases free chlorine atoms.
- Ozone depletion through CIO (Chlorine Monoxide)
When free chlorine atoms (present in the atmosphere) react with O3 (ozone), then it forms CIO (chlorine monoxide) and an oxygen molecule. This chlorine monoxide then reacts with an ozone molecule to form a chlorine atom and two oxygen molecules. Again, this chlorine atom forms chlorine monoxide by reacting with the ozone molecule. In this way, the process keeps on going, which causes ozone depletion.
- Other chemicals that affect ozone depletion
Apart from CFCs, HCFCs, ODS, etc. many other chemicals influence ozone depletion. Some of these chemicals are Hox, Clx, Noy, etc. These chemicals are also from the families of hydrogen, chlorine, and nitrogen. These chemicals also affect the ozone layer when reacts with ozone atoms near the stratosphere layer of Earth’s atmosphere.
- Rocket launches
Unregulated rocket launches are also important causes of ozone depletion. As per the studies, it has been observed that rocket launches are affecting the ozone layer much more as compared to CFCs and HCFCs.
It has been estimated through various studies that if unregulated rocket launches continue, then we will have a massive loss in the ozone layer in the upcoming generations.
- Global warming also causes ozone depletion
Global warming is one of the big environmental issues at present. It is affecting the environment in different ways, starting from climate change, extreme weather events, disturbing the ecosystem and biodiversity of the planet to ozone layer depletion.
Due to greenhouse gases and global warming, a vast amount of heat is getting absorbed in the troposphere, which is the lower layer of the stratosphere. As ozone is available in the stratosphere layer of Earth’s atmosphere, thus the heat is not able to reach the troposphere and remains cold.
On the other hand, the ozone layer needs a lot of sunlight and heat to recover, but due to lack of sunlight & heat, it starts depleting. Eventually, it becomes one of the vital causes of the ozone layer hole.
Ozone layer depletion is one of the big crises for humankind. Ozone depletion results in increasing ultraviolet radiation hitting the Earth’s surface. This UV-radiation affects the ecosystem very severely, causing various health problems for the living organisms of the planet.
Hence, we should spread awareness among all are peer-groups about the causes of ozone layer depletion. We also need to be aware of the harmful effects of ozone depletion and how we can handle this vital environmental issue.
We should try to handle ozone layer depletion at an individual level. Try to minimize the use of products, appliances, equipment, etc. that emits ODS (ozone depleting substances). Our continuous attempt will work to make this planet a sustainable place to live for each organism peacefully.