Green Houses Gases and its Effects

1. What is GreenHouse Gas?
• A greenhouse gas is a gas that absorbs and emits radiant energy
within the thermal infrared range.
• Greenhouse gases cause the greenhouse effect.
• Without greenhouse gases, the average temperature of Earth's surface
would be about −18 °C rather than the present average of 15 °C .
• The atmospheres of Venus and Mars also contain greenhouse gases.

2. What is GreenHouse Effect?
• The greenhouse effect is defined as when the Earth's atmosphere
becomes thick with gases and substances which trap the sun's
radiation, making the Earth warmer.
• An example of the greenhouse effect is global warming.

3. Types of GreenHouse Gases

4. 1) Methane (CH4)
Origin
• Burning of biomass
• Rice paddies
• Fermentation by enteric bacteria
Sink
• Microorganisms uptake
• Reactions associated with hydroxyl groups
Contribution to GreenHouse Effect
• Absorption of infrared radiation
• Indirectly affects the concentration of ozone and water vapor in the
stratosphere
• Production of carbon dioxide

5. 2) Nitrous Oxide (N2O)
Origin
• Burning of Biomass
• Combustion of fossil fuels
• Fertilizers
Sink
• Removal by soils
• Photolysis in the stratosphere
Contribution to GreenHouse Effect
• Absorption of infrared radiation
• Indirectly affects the concentration of ozone in the stratosphere

6. 3) Carbon dioxide (CO2)
Origin
• Burning of fossil fuels
• Deforestation
Sink
• Plants undergoing photosynthesis
• Oceans
Contribution to GreenHouse Gases
• Absorption of infrared radiation
• Indirectly affects the concentration of ozone in the stratosphere.

7. 4) Ozone (O3)
Origin
• Chemical reactions that involve oxygen
Sink
• All catalytic chemical reactions that involve nitrous oxide,
hypochlorite, and hydroxyl species
Contribution to GreenHouse Effect
• Absorption of infrared and ultraviolet radiation

8. 5) Chlorofluorocarbons (CFCs)
Origin
• Industrial production
Sink
• Photolysis and reaction with oxygen
Contribution to GreenHouse Effect
• Absorption of infrared radiation
• Indirectly affects the concentration of ozone in the stratosphere

9. 6) Carbon Monoxide (CO)
Origin
• Plant emissions
• Man-made release (transport & industrial)
Sink
• Soil uptake
• Reactions with OH
Contribution to GreenHouse Effect
• Affects stratospheric O3 and OH cycles
• Produces CO2

10. 7) Sulphur Dioxide (SO2)
Origin
• Volcanoes
• Coal and Biomass burning
Sink
• Dry and wet deposition
• Reactions with OH
Contribution to GreenHouse Effect
• Forms aerosols, which scatter solar radiation