Global Warming

1
Global Warming

• Green House Gases

how global warming works
how global warming works
2
Green house gases

• Many greenhouse gases occur naturally in the
  atmosphere, such as water vapor (36-70), Carbon
  dioxide (9-26), Methane ( 4-9) and nitrous
  oxide, while others are synthetic.
• Those that are man-made (lower end) include the
  Chlorofluorocarbons (CFCs), Hydrofluorocarbons
  (HFCs),
• Perfluorocarbons (PFCs),
• Sulfur hexafluoride (SF6).

3
Water Vapour

• Water Vapor is the most abundant greenhouse gas
  in the atmosphere.
• Although the media gives impression that (CO2) is
  "the big one". water vapor is actually the
  dominant greenhouse gas in Earth's atmosphere.
• As the temperature of the atmosphere rises, more
  water is evaporated from ground storage (rivers,
  oceans, reservoirs, soil.
• Water, in gaseous form (as water vapor) and in
  liquid form (as tiny droplets in clouds),
  generates somewhere between 66 and 85 of the
  greenhouse effect

4
..Water Vapour

• Water vapor generates more greenhouse effect on
  our planet than does any other single gas.
• As water vapor increases in the atmosphere, it
  eventually also condense into clouds, which are
  more able to reflect incoming solar radiation
  (thus allowing less energy to reach the Earth's
  surface and heat it up) ( Refer Water cycle).

5
Water cycle
6
Carbon dioxide (CO2)

• CO2 is a green gas next to water vapour it
  helps trap heat coming from the Sun in our
  atmosphere through the green house effect.
• Carbon dioxide occur naturally in the atmosphere,
  through our interference with the carbon cycle
  (through burning forest lands, or mining and
  burning coal).
• We artificially move carbon from solid storage
  to its gaseous state, thereby increasing
  atmospheric concentrations.

7
.Carbon dioxide (CO2)

• Carbon dioxide traps heat in the atmosphere.
• Without it and other greenhouse gases, Earth
  would be a frozen world.
• Humans have burned so much fuel that there is
  about 30 more carbon dioxide in the air today
  than there was about 150 years ago.

8
Carbon Dioxide ( CO2)

• Concentrations of carbon dioxide in the
  atmosphere are naturally regulated by numerous
  processes collectively known as the carbon
  cycle ( Ref Carbon cycle)
• We breath in O2 and give out CO2
• When humans burn fossil fuels to power factories,
  power plants, cars and trucks, most of the carbon
  quickly enters the atmosphere as carbon dioxide (
  five and a half billion tons of carbon each
  year).

9
.CO2

• Natural fires like forest fires make carbon
  dioxide.
• Things that humans burn make CO2.
• The smoke stacks of factories that burn coal give
  off carbon dioxide.
• The engines of cars, trucks, and buses also pump
  carbon dioxide into the air.
• Vehicles give off another gas, carbon monoxide,
  which combines with O2 and form CO2

10
Carbon cycle
11
Nitrous oxide

• Nitrous oxide (N2O) is produced by both natural
  and human-related sources.
• Primary human-related sources of N2O are
  agricultural soil management, animal manure
  management, sewage treatment, mobile and
  stationary combustion of fossil fuel,, and nitric
  acid production.
• Nitrous oxide is also produced naturally from a
  wide variety of biological sources in soil and
  water, particularly microbial action in wet
  tropical forests ( Ref. nitrogen cycle).

12
Nitrogen Cycle
13
Other Green Gas- Methane

• When most people think of climate change they
  envision billowing smokestacks, and diesel
  engines responsible for releasing carbon dioxide
  into the atmosphere.
• We over looking a far more inconspicuous culprit
  methane emissions of which may be slowing
  down.

14
Methane manufacturers. CREDIT USDA ARIS
INFORMATION STAFF
15
.Other Green Gas- Methane

• The Earth's crust contains huge amounts of
  methane.
• It is a chemical compound with the molecular
  formula CH4.
• It is a relatively potent greenhouse gas with a
  high global warming potential.
• Burning methane in the presence of oxygen
  produces carbon dioxide and water.

16
.Other Green Gas -Methane

• Methane is the second most abundant greenhouse
  gas, behind only carbon dioxide, according to the
  new report from the United Nations
  Intergovernmental Panel on Climate Change.
• Most natural methane comes from bacteria that
  live in wetlands and marshes, which multiply
  quickly in wet or warm seasons.
• Large amounts of methane are produced
  anaerobically

17
.Other green House gases

• Haloalkanes
• Consisting of alkanes, such as methane or
  ethane, with one or more halogens linked, such as
  chlorine or fluorine
• Used as flame retardants, fire extinguishants,
  refrigerants, propellants and solvents they have
  or had wide use
• Chlorofluorocarbons (CFC)
• Contains Chlorine
• Gases such as CFCs had damaged the ozone layer,
  creating a huge hole through which dangerous
  ultraviolet light could penetrate.
• .

18

• Hence, it is forbidden to release CFC gasses into
  the atmosphere, so all redundant refrigeration
  plant, including air-conditioning and domestice
  fridges and freezers must be properly
  decommissioned and drained of their CFC gasses by
  a trained and certified technician.
• Hydrofluorocarbons (HFCs)
• contain no chlorine. They are composed entirely
  of carbon, hydrogen, and fluorine.
• They have no known effects at all on the ozone
  layer.
• Only compounds containing chlorine and bromine
  are thought to harm the ozone layer.

19
Green House Gas in the atmosphere
20
References

• http//lwf.ncdc.noaa.gov/oa/climate/gases.htmlINT
  RO
• http//www.eia.doe.gov/bookshelf/brochures/greenho
  use/Chapter1.htm
• http//www.solarnavigator.net/greenhouse_gases.htm
  
• http//www.neuse.ncsu.edu/nitrogen/
• http//www.epa.gov/nitrousoxide/sources.html
• http//www.umich.edu/gs265/society/greenhouse.htm
  

21

• http//scienceline.org/2007/03/23/env_knight_ipccc
  ows/
• http//da.wikipedia.org/wiki/CFC-gas