Emission of greenhouse gasses is the cause of ozone layer depletion. This is a greatest challenge facing the world especially the industrialized world.

I agree with Isa Baba Koki

The ozone hole over the Antarctic has varied in size ever since we were aware that it existed.

Burning fossil fuels, Clearing forests and degrading other ecosystems is responsible for Ozone depletion. All these activities emit heat-trapping carbon dioxide into the air. Cattle, rice fields, landfills, and fossil fuel operations release methane—a gas that warms the planet even more. Nitrous oxide and fluorinated gases seep out of agricultural lands, industrial sites, refrigeration systems, and urban areas, adding still more heat-trapping pollutants to Earth’s atmosphere@Azad

The causes are well known. Fossil fuel burning is not a primary cause. The most common greenhouse gasses (CO2, CH4) do not have a major impact. N2O is a greenhouse gas and does deplete O3, but it has a short lifetime and is not a primary cause of the Antarctic ozone "hole." CFCs are the main culprit. The "hole" has been observed to be recovering, slowly, mainly due to reductions in CFC emissions.

Here's some basic information:

https://www.epa.gov/ozone-layer-protection/basic-ozone-layer-science

And much more detail:

https://esrl.noaa.gov/csl/assessments/ozone/

Dear Md A.K Azad,

“Ozone layer depletion is the gradual thinning of the earth’s ozone layer in the upper atmosphere caused due to the release of  chemical compounds containing gaseous bromine or chlorine from industries or other human activities.”

What is Ozone Layer Depletion?

Ozone layer depletion is the thinning of the ozone layer present in the upper atmosphere. This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules. One chlorine can destroy 100,000 molecules of ozone. It is destroyed more quickly than it is created.

Some compounds release chlorine and bromine on exposure to high ultraviolet light, which then contributes to the ozone layer depletion. Such compounds are known as Ozone Depleting Substances (ODS).

The ozone-depleting substances that contain chlorine include chlorofluorocarbon, carbon tetrachloride, hydrochlorofluorocarbons, and methyl chloroform. Whereas, the ozone-depleting substances that contain bromine are halons, methyl bromide, and hydro bromofluorocarbons.

Chlorofluorocarbons are the most abundant ozone-depleting substance. It is only when the chlorine atom reacts with some other molecule, it does not react with ozone.

Montreal Protocol was proposed in 1987 to stop the use, production and import of ozone-depleting substances and minimize their concentration in the atmosphere to protect the ozone layer of the earth.

Causes of Ozone Layer Depletion

The ozone layer depletion is a major concern and is associated with a number of factors. The main causes responsible for the depletion of the ozone layer are listed below:

Chlorofluorocarbons

Chlorofluorocarbons or CFCs are the main cause of ozone layer depletion. These are released by solvents, spray aerosols, refrigerators, air-conditioners, etc.

The molecules of chlorofluorocarbons in the stratosphere are broken down by the ultraviolet radiations and release chlorine atoms. These atoms react with ozone and destroy it.

Unregulated Rocket Launches

Researches say that the unregulated launching of rockets result in much more depletion of ozone layer than the CFCs do. If not controlled, this might result in a huge loss of the ozone layer by the year 2050.

Nitrogenous Compounds

The nitrogenous compounds such as NO2, NO, N2O are highly responsible for the depletion of the ozone layer.

Natural Causes

The ozone layer has been found to be depleted by certain natural processes such as Sun-spots and stratospheric winds. But it does not cause more than 1-2% of the ozone layer depletion.

The volcanic eruptions are also responsible for the depletion of the ozone layer.

Ozone Depleting Substances (ODS)

“Ozone depleting substances are the substances such as chlorofluorocarbons, halons, carbon tetrachloride, hydrofluorocarbons, etc. that are responsible for the depletion of ozone layer.”

Following is the list of some main ozone-depleting substances and the sources from where they are released:

Ozone-Depleting Substances

Sources

Chlorofluorocarbons (CFCs)

Refrigerators, air-conditioners, solvents, dry-cleaning agents, etc.

Halons

Fire-extinguishers

Carbon tetrachloride

Fire extinguishers, solvents

Methyl chloroform

Adhesives, aerosols

Hydrofluorocarbons

Solvent cleaning, fire extinguishers, solvent cleaning

Also Read: Global Warming

Effects Of Ozone Layer Depletion

The depletion of the ozone layer has harmful effects on the environment. Let us see the major effects of ozone layer depletion on man and environment.

Effects on Human Health

The humans will be directly exposed to the harmful ultraviolet radiations of the sun due to the depletion of the ozone layer. This might result in serious health issues among humans, such as skin diseases, cancer, sunburns, cataract, quick ageing, and weekend immune system.

Effects on Animals

Direct exposure to ultraviolet radiations leads to skin and eye cancer in animals.

Effects on the Environment

Strong ultraviolet rays may lead to minimal growth, flowering and photosynthesis in plants. The forests also have to bear the harmful effects of the ultraviolet rays.

Effects on Marine Life

Planktons are greatly affected by the exposure to harmful ultraviolet rays. These are higher in the aquatic food chain. If the planktons are destroyed, the organisms present in the lower food chain are also affected.

Solutions to Ozone Layer Depletion

The depletion of the ozone layer is a serious issue and various programmes have been launched by the government of various countries to prevent it. But, steps should be taken at the individual level as well to prevent the depletion of the ozone layer.

Following are some points that would help in preventing this problem at a global level:

Avoid Using Pesticides

Natural methods should be implemented to get rid of pests and weeds instead of using chemicals. One can use eco-friendly chemicals to remove the pests or remove the weeds manually.

Minimize the Use of Vehicles

The vehicles emit a large amount of greenhouse gases that lead to global warming as well as ozone depletion. Therefore, the use of vehicles should be minimized as much as possible.

Use Eco-friendly Cleaning Products

Most of the cleaning products have chlorine and bromine releasing chemicals that find a way into the atmosphere and affect the ozone layer. These should be substituted with natural products to protect the environment.

The Use of Nitrous Oxide should be Prohibited

The government should take actions and prohibit the use of harmful nitrous oxide that is adversely affecting the ozone layer. People should be made aware of the harmful effects of nitrous oxide and the products emitting the gas so that its use is minimized at the individual level as well.

N.B:***For more insights pls refer my research article.

**** Mitigation Strategies to Greenhouse Gas Emission Control: A Database for Emission Factors (IJSRD/Vol. 3/Issue 10/2015/203

( T. Arfin1 Md.O. Aquatar2 S. S. Waghmare3 1Scientist 2Research Scholar 3Senior Scientist 1,2,3Department of Environmental Engineering 1,2,3Environmental Materials Division, CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nagpur-440020, India (PDF) Mitigation Strategies to Greenhouse Gas Emission Control: A Database for Emission Factors. Available from: https://www.researchgate.net/publication/291349360_Mitigation_Strategies_to_Greenhouse_Gas_Emission_Control_A_Database_for_Emission_Factors [accessed Sep 18 2020]. ) With Warm Regards,

Md Osim Aquatar,India

When the "disappearing ozone" was first discovered in the 1960s, academic chemists were observing a natural phenomenon of increasing/decreasing that was never known before with O3. Political action and reaction led to UN treaties to try "and stop it" : discovering scientists were draped with awards as thanks from entrenched bureaucrats and billionaires.

Ozone forms from a chemical compound bond as broken down by photons (light, as in STRONG SUNLIGHT with ALL its radiation) of O2 into two (2) Oxygen ions, which then react with another O2 molecule to form the triatomic ozone (O3). O3 is unstable and decays back to O2. But it lingers long enough to block selected bands of UV radiation.

The thinning of the ozone layer occurs during the sunless polar winters and is thinnest in the polar spring, "normally," as part of seasonal cyclicity (we now know) in space weather (something readers here should be getting acquainted with more and more). The layer rapidly renews during the sunlit spring and summer months (we now know). This effect is most pronounced in Antarctica because the powerful continuous, circumpolar winds essentially isolate Antarctica from any ozone produced in the mid-latitudes.

Due to weakened solar activity recently, the "ozone holes" people were worried about for 50 years started to refill and are currently "back to normal" since weaker sun activity somehow is keeping O3 in "place" (not "thinning.") This makes UN treaties for it an embarrassment that is constantly trying to be politically "fixed" by vested-interest bureaucrats and business people who are attempting constantly to rob Third World nations of cheap, safe refrigeration like you still get in NYC and Boston; London and Paris. This is shameful, cruel, and even ludicrous: Freons (Registered trade mark) "man-made" "CFC/HFC" compounds are 4x heavier than air we breathe in the troposphere. How can it reach the top of the troposphere, let alone the higher ozone hole in the stratosphere? The only reason that chlorinated and brominated compounds get up there is due to volcanic emissions (usually stratovolcanoes, which "inject" the stratosphere with aerosols and dust like a powerful syringe shooting upward). (Note also that free radicals of these compounds occur NATURALLY.) Tierra del Fuego’s volcanoes and Mt. Erebus affect Antarctica. Iceland’s volcanoes affect the Arctic. Human bromide, chlorine action (ie Freon) is MINISCULE compared to volcanic contributions in effecting BOTH ozone layers.

According to me, consider a small experiment using candle flame. If we consider a 1 Centimenter width candle, when we light it, the flame burns 3 cm X 3 cm area of gas. If we consider the thermal energy released by ground level nuclear fusion and fission tests, the flame burns almost 300 km x 300 km surface area even upto 20 in atmosphere. Is it also a chance that it expands over whole atmosphre even beyond 40,000 km. If the analogy is right, think the surface area Vs Oxygen, Ozone density. from this, the nuclear tests are the major cause of ozone depletion.

Humans expect to have refrigerants and air conditioners (which used to use ozone-killer CFC's) as well as protection from the ozone layer!

Well, you can't have both.

There is a need to find refrigerants that do not use chlorine. If one can do that, then one can enjoy protection from the ozone layer.