Biosphere reserves in India:

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Biosphere reserves in India
Nilgiri Biosphere Reserve - Tamil Nadu Nilgiri
Biosphere Reserve - Kerala Nilgiri Biosphere
Reserve - Karnataka Nanda Devi Biosphere Reserve
Uttaranchal Nokrerk Biosphere Reserve -
Meghalaya Manas Dibru-Saikhowa Biosphere
Reserve - Assam Sunderbans Biosphere Reserve -
West Bengal Gulf of Mannar Biosphere Reserve -
Tamil Nadu Great Nicobar Biosphere Reserve - AN
islands Similpal Biosphere Reserve - Orissa
Dehang Debang Biosphere Reserve - Arunachal
Pradesh Pachmarhi Biosphere Reserve - Madhya
Pradesh Kanchanjanga Biosphere Reserve - Sikkim
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Atmosphere

• Earth is enveloped by a gaseous layer
• This layer sustains life or earth and saves it
  from dangerous environment of outer space
• Absorbs most of cosmic rays from outer space
• Transmits only near UV, Visible near infrared
  radiation and radio waves while filtering out
  dangerous ultra violet radiations
• Helps maintaining habitable temp on the planet by
  maintaining the heat balance on earth.

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• Troposphere Lowest layer of Atmosphere close
  to earth surface, 20km above. Turbulent zone of
  strong air movement and all climatic and weather
  changes takes place. Most imp. Zone of the
  atmosphere for organisms.
• Stratosphere Lies between 14-50km above earths
  surface. It is zone of atmosphere. Ozone is
  present in the immediate upper layer called
  stratopause which absorbs UV radiation of sun,
  hence increase in temp.
• Mesosphere 50 90km from earths surface,
  coldest region of Atmosphere.

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• Thermosphere Temp. increases with height.
  Includes region in which UV radiation and Cosmic
  rays cause ionization of Oxygen and Nitric oxide
  molecules.
• Exosphere Region above thermosphere. Outer
  space which extends up to 32,190 km from earth.
  Very high temp. due to solar radiation.
• Hydrosphere Oceans, seas, rivers, glaciers,
  lakes, reservoirs, polar ice caps and shallow
  ground water bodies.
• Approximately 70.8 of earth surface is
  covered with water mainly from oceans
• 97 - high salt concentration 2 - ice caps
  Less than 1 - fresh water

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Problems

• Slightest variation in the composition,
  structure or function of the atmosphere through
  human interference will invite lot of serious
  environmental problems
• climate change, El Nino effect, global warming,
  Green house effect, ozone depletion, ozone hole
  etc.
• These damages are quite difficult to repair
  unless man decides to improve on his mistakes.
• There can only be reduction in further
  environmental damages and not the repair

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Ozone Layer
Ozone (O3) is a triatomic molecule, consisting
of three oxygen atoms. It is an allotrope of
oxygen that is much less stable than the
diatomic species O2. Ground-level ozone is an
air pollutant with harmful effects on the
respiratory systems of animals. Ozone in the
upper atmosphere filters potentially damaging
ultraviolet light from reaching the Earth's
surface. It is present in low concentrations
throughout the Earths atmosphere.
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CFCs
CFC s are used in coolants in our homes, cars and
refrigerators as foaming agents in foam
insulation, mattresses, and food packaging and
as solvents that remove impurities from computer
microchips and electronic equipment. The same
properties that make CFCs efficient and safe for
so many industrial uses also make them
destructive for the environment. One of these
atoms, chlorine has a devastating effect on
ozone. Other compounds called halons, used in
some fire extinguishers, are even more
destructive of ozone.
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Ozone depletion

• A slow, steady decline of about 4 percent per
  decade in the total amount of ozone in Earths
  atmosphere, since around 1980 and a much larger,
  but seasonal, decrease in stratospheric ozone
  over Earth's polar regions during the same
  period.
• CFCs, halons (bromofluorocarbon compounds) and
  other contributory substances are commonly
  referred to as ozone-depleting substances (ODS).

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Ozone depletion

• There has been a rapid decline in the amount of
  ozone over the
• Antarctic region since the 1970s, leading to the
  formation of the ozone
• 'hole'.
• Ozone loss over the Antarctic appears to have
  stabilised in the 1990s,
• but between 1998 and 2001, the size of the ozone
  hole covered an area
• of approximately 26 million km2, nearly three
  times the area of Australia.
• After the hole was discovered, many industries
  stopped releasing
• ozone-depleting chemicals into the atmosphere.
• An international agreement known as the Montreal
  Treaty intends
• to reduce the emission of ozone depleting
  chemicals.