What is ozone layer? Ozone layer is a layer of gas that sits km above earths surface. It mainly contains contain ozone which is a naturally occurring. - презентация

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2 What is ozone layer? Ozone layer is a layer of gas that sits km above earths surface. It mainly contains contain ozone which is a naturally occurring molecule containing three oxygen atoms. This layer is present in the stratosphere and prevents too many harmful UV (ultra violet) radiations from entering the earth.

3 Why Ozone Layer is Necessary? An essential property of ozone molecule is its ability to block solar radiations. In this process, it also absorbs ultraviolet radiations that are dangerous for most living beings. UV radiation could injure or kill life on Earth.

4 Causes of ozone depletion Human activity Natural sources Volcanic eruptions

5 Human activity Human activity such as the release of various compounds containing chlorine or bromine can be major cause of ozone damage. Perhaps the most evident and destructive molecule is the chlorofluorocarbon (CFC). CFC is commonly used in refrigerators, air conditioners, cleaning agents, packing material, car emissions, aerosol spray cans and etc.

6 Natural sources Natural sources also contribute to the depletion of the ozone layer. A common natural source of ozone damage is naturally occurring chlorine. Naturally occurring chlorine has detrimental effects and possess danger to the earth.

7 Volcanic eruptions Volcanic eruptions are a small contributor to ozone damage. During large volcanic eruptions chlorine, as a component of hydrochloric acid is released directly into the stratosphere along with Sulphur dioxide. In this case Sulphur dioxide is more harmful than chlorine because it is converted to sulphuric acid aerosols. These aerosols accelerate damaging chemical reactions, which cause chlorine to destroy ozone.

8 Effects of ozone layer depletion Effect on Human Health: Skin Cancer, Cataracts and other eye damage, Damage to Immune system, Aging of skin. Effect on Climate: Ozone in the lower atmosphere contributes to global warming and climate change. The depletion of ozone layer has trickle down effects in the form of global warming, which in turn leads to melting of polar ice, which will lead to rising sea levels and climatic changes around the world. Effect on Aquatic System: UV rays also have adverse effect on the marine ecosystem. It adversely affects the planktons which plays a vital role in the food chain and oceanic carbon cycle. Affecting phytoplankton will in turn affect the whole ocean ecosystem.

9 Buy air-conditioning and refrigeration equipment that don't use CFCs as refrigerant. Use eco-friendly household cleaning products. Buy aerosol products that don't use CFCs as propellants. Avoid using pesticides. When motor vehicle air-conditioners need servicing, make sure that the refrigerants are properly recovered and recycled instead of being vented to the atmosphere. What can we do? At individual level everyone can contribute towards reducing ozone layer depletion. Buying and using recycled products, saving of energy, using of public transport, limit private vehicle driving can do a lot in combating ozone layer depletion.

10 Some Facts The ozone layer was discovered in 1913 by the French physicists Charles Fabry and Henri Buisson.Charles Fabry Henri Buisson Ozone layer is capable of absorbing % of the harmful ultraviolet radiations that are emitted by sun. In 1994, the United Nations General Assembly voted to designate September 16 as "World Ozone Day". The largest "ozone hole" was discovered in Antarctica

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