The ozone layer is a naturally occurring gas found in the stratosphere where ozone particles accumulate. It is formed through natural processes but balanced so the total amount remains constant, though thickness varies with altitude and season. Major causes of ozone depletion include chlorofluorocarbons (CFCs), unregulated rocket launches, global warming, and nitrogenous compounds from human activities. Ozone depletion allows more harmful UV radiation to reach the Earth, negatively impacting human health through increased risks of skin cancer, eye disease, and suppressed immunity, as well as environmental effects like DNA damage and lung diseases.

1. Ozone Layer
The ozone layer is basically naturally occurring gas in the
region of stratosphere where ozone particles are
accumulated . Ozone layer is also naturally broken down but
there is a balance between its formation and natural
depletion. As a result the total amount of ozone remains
constant. But ozone layer thickness varies with altitude and
seasonal change. Ozone concentration is highest between
19 - 23 km . Most of ozone is formed at equator where
there is maximum sunshine but with winds it travels at high
altitude and get accumulated in stratosphere .

2. Causes of Ozone Depletion
Chlorofluorocarbons
CFCs are highly volatile and non combustible so they are very quickly
evaporated and can easily reach in stratosphere where ozone is present here
they start depleting ozone molecules. These CFCs have also adverse affects on
human health.
Unregulated Launches of Rockets
Another major cause of large scale ozone depletion is Rocket launches. It has
been studied that unregulated rocket launches can result in much more ozone
depletion than CFCs. It is estimated that if rocket launches will be let
unregulated then it would cause huge ozone loss by the year 2050 than the
CFCs have done.
Global Warming
Global warming also leads to ozone layer depletion. Due to global warming
and green house effect most of the heat is trapped in troposphere which is the
layer below the stratosphere.
Nitrogenous Compound
Nitrogenous Compounds emitted by human activities in small amount like NO,
N2O and NO2 are considered to be greatly responsible for the depletion of
ozone layer

3. Effects of Ozone Depletion
Ozone depletion is affecting the human health
and environment negatively, as it allows the
penetration of UV radiations to reach the
Earth. These radiations can cause severe
diseases in humans such as skin cancer, eye
damage and genetic mutations etc.

4. Effects on Eyes
The major cause of blindness in this world is cataracts. There would be
0.3% - 0.6% increase in risk of cataract if there will be 1% decrease in
Ozone level
Effects on Skin
Skin is the most often exposed part of body to UV radiations There are
two types of skin cancer, Melanoma and Non-melanoma. Melanoma is
most serious form of cancer and is often fatal, while non-melanoma is
most common type and less fatal
Effects on Human Immunity
Exposure to UV radiations can also result in suppression of immune
response to skin cancer, infectious diseases and other antigens
DNA Damage and Lung Diseases
Short exposure to UV-B radiations can cause the DNA damage because
UV radiations can disturb bio molecules such as lipids, proteins and
Nucleic acids. Due to UV-B radiations there would be cryptic
transposable elements which may lead towards the mutations which is
more dangerous than the immediate DNA damage.

5. What is Global Warming?
Global warming is the slow increase in the average temperature
of the earth’s atmosphere because an increased amount of the
energy (heat) striking the earth from the sun is being trapped in
the atmosphere and not radiated out into space.
The earth’s atmosphere has always acted like a greenhouse to
capture the sun’s heat, ensuring that the earth has enjoyed
temperatures that permitted the emergence of life forms as we
know them, including humans.
Without our atmospheric greenhouse the earth would be very
cold. Global warming, however, is the equivalent of a
greenhouse with high efficiency reflective glass installed the
wrong way around.

6. Ironically, the best evidence of this may come from a terrible
cooling event that took place some 1,500 years ago. Two massive
volcanic eruptions, one year after another placed so much black
dust into the upper atmosphere that little sunlight could
penetrate. Temperatures plummeted. Crops failed. People died
of starvation and the Black Death started its march. As the dust
slowly fell to earth, the sun was again able to warn the world and
life returned to normal.
Today, we have the opposite problem. Today, the problem is not
that too little sun warmth is reaching the earth, but that too
much is being trapped in our atmosphere.
So much heat is being kept inside greenhouse earth that the
temperature of the earth is going up faster than at any previous
time in history. NASA provides an excellent course module on the
science of global warming.

7. WHAT IS CARBON TRADING?
• Carbon trading is the process of buying and
selling permits and credits that allow the permit
holder to emit carbon dioxide. It has been a
central pillar of the EU’s efforts to slow climate
change.
• The world’s biggest carbon trading system is the
European Union Emissions Trading System (EU
ETS). It is beset with problems and corruption
and yet countries such as Brazil and China
continue to pursue carbon trading as a way to
tackle rising emissions.

8. How do carbon trading permits work?
The model used in all current carbon trading schemes is called
‘cap and trade’. In a ‘cap and trade’ scheme, a government or
intergovernmental body sets an overall legal limit on emissions
(the cap) over a specific period of time, and grants a fixed
number of permits to those releasing the emissions. A polluter
must hold enough permits to cover the emissions it releases.
Each permit in the existing carbon trading schemes is considered
equivalent to one tonne of carbon dioxide equivalent (CO2e). In
the theoretical model, (but rarely in practice) permits are to be
sold – usually by auction – so that from the outset, polluters are
forced to put a price on their emissions, and are incentivised to
reduce to a bare minimum the permits they seek.