Seminar Report on OZONE LAYER DEPLETION & THE MONTREAL PROTOCOL

2014-2015Chetan Sharma

M.Sc. I sem.

School Of Studies In Environment Management Vikram University, Ujjain

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Introduction Ozone layer formation Ozone layer depletion Effects depletion The Montreal protocol Conclusion Reference

SYNOPSIS

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INTRODUCTIONThe ozone layer was discovered in 1913 by the French physicists Charles Fabry and Henri Buisson. Ozone layer is a thin, fragile shield that contains relatively high concentrations of ozone.It shields the entire Earth from much of the harmful UV radiation that comes from the sunThe atmosphere of the Earth is divided into 5 layers.The layers are: troposphere, stratosphere, mesosphere, thermosphere and exosphere.Ozone is a triatomic form of oxygen (O3) found in Earth’s upper and lower atmosphere. Humans rely heavily on the absorption of ultraviolet B rays by the ozone layer because UV-B radiation causes skin cancer and can lead to genetic damage.

Layers of the Earth’s Atmosphere

Ozone is found in both the troposphere (lower atmosphere) and the stratosphere

Ozone formation Ozone (O3) Chemically forms when UV hits on stratosphere Oxygen molecules dissociate into atomic oxygen

Atomic oxygen quickly combines with other oxygen molecules to form ozone

O2 O + O

O + O2 O3

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THE OZONE LAYER DEPLETION

Ozone layer is being destroyed by a group of manufactured chemicals that are called ODS or Ozone-Depleting Substances.

The main ODS are the following:

Chlorofluorocarbons (CFC 11, CFC 12, CFC 13)

Methyl bromide (CH3Br)

Halons (halon-1211, halon-1301, halon-2402)

Carbon tetrachloride (CCI4)

Hydrochloroluorocarbons (HCFC 22 and HCFC 123)

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THE OZONE HOLE AND ITS CAUSES

Recently, chlorofluorocarbons (CFCs) were used a lot in industry and elsewhere to keep things cold and to make foam and soaps.

Strong winds carry CFCs up into the stratosphere where UV radiation breaks them apart, releasing chlorine atoms.

Each chlorine atom can attack and break apart (destroy) as many as 100,000 ozone molecules during the time it is in the stratosphere.

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The chlorine from CFCs reduces (depletes) the amount of ozone in the stratosphere.

Other ozone-eating chemicals are pesticides such as methyl bromide, halons used in fire extinguishers, and methyl chloroform used in businesses.

Hole in the ozone layer

October 1979

October 2007

Some Effects of Ozone Layer DepletionHuman Health

Damages DNA which suppresses immune system resulting in increase in infectious diseases e.g. , Skin Cancer; Eye Cataracts

Plants & TreesReduces crop production, damage to seedsReduces quality of crops, damage to leaves.

Aquatic OrganismsDamage to plankton, aquatic plants, fish larvae, shrimp, crabsAffects marine food chain

Materialsdegrades paints, rubber, wood, & plastics, especially in tropical regions

Ground Level Smog Increase in the formation of Ground level ozone as a pollutant High economic cost Damages could be in billions of US dollars

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An international agreement , signed by most of the industrialized nations, to substantially reduce the use of chlorofluorocarbons (CFCs).

The Montreal Protocol on Substances that Deplete the Ozone Layer was designed to reduce the production and consumption of ozone depleting substances in order to reduce their abundance in the atmosphere, and thereby protect the earth’s fragile ozone Layer.

The protocol set limits on the production of chlorofluorocarbons (CFCs), halons, and related substances that release chlorine or bromine to the ozone layer of the atmosphere.

THE MONTREAL PROTOCOL(1989)

Results to date The Montreal Protocol is working.

There is clear evidence of a decrease in the atmospheric burden of ozone-depleting substances in the lower atmosphere and in the stratosphere;

Some early signs of the expected stratospheric ozone recovery are also evident.

Furthermore, if the Parties were to eliminate all emissions of ozone depleting substances soon after 2006, it would advance by about 15 years (from around 2050 to 2035) the global ozone layer recovery to pre-1980 levels

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Without the Montreal Protocol by 2050

Ozone depletion would have reached to at least 50 % in the northern hemisphere’s mid latitudes

70% in the southern mid latitudes Doubling on the UV-B radiation reaching earth’s

surface Estimated increases of

19 million more cases of non-melanoma cancer 1.5 million more cases of melanoma cancer 130 million more eye cataracts

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There are many possible solutions to this problem, but it wholly relies on us, humans.. The following are the soltuions for decreasing the ozone hole in the atmosphere:-Firstly the consumption all the cfcs should be Companies should be held responsible for the disater

they are causing in the environment And we should use the 3rs…. Which are reuse , recycle,

reduce initiative… so that the next generation doesnot have to go through problems made by us.

And the use of cfcs should be ban.

CONCLUSION

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ELEMENTS OF ENVIRONMENT (English) 6th Edition (1995)by robert smith.

Ecosystem Principles and Sustainable Development (1999) by swaminatham.

Wikipedia.com/ozone layerBooks.google/ozone layer depletion

REFERENCE

Thank you..