1. Greenhouse Gases
GHG’s

2. GHG’s and Global Warming
Over the past 100 yrs, temp has increased approx. ½ degrees Celsius (1 degree Fahrenheit)
The reason why some scientists believe global warming is occurring-too much GHG
Global Warming – The increase of Earth’s overall temperature
Others believe this is a natural phenomenon

3. Greenhouse Effect
GHG’s allow solar radiation to pass through the atmosphere but prevent most of the outgoing heat from escaping back to space.

4. Five Main GHG’S Carbon dioxide CO2 Methane CH4 Nitrous Oxide N2O
Water vapor H2O
Chlorofluorocarbons
CFC’s

5. Function of GHG’s Help keep world’s temp in balance.
GHG’s need to stay in balance (can’t have too many or too few)
Act like a blanket and keep heat around Earth

6. Water Vapor Causes about 65% of the greenhouse effect
Enters atmosphere through evaporation

7. Carbon Dioxide 2nd most abundant 25% of GHG’s
People and animals give off CO2
Dead plants/trees give it off
Burning plants/trees
Burning fossils fuels
Stays in the atmosphere for yrs

8. Methane CH4 3rd most abundant
Released when organic matter decomposes w/out oxygen
Cows are the largest natural producers
Natural gas is another source of methane
Stays in atmosphere for 12 yrs
Traps heat 23 times greater than carbon dioxide

9. Nitrous Oxide Released from manure and fertilizers
Stored in soil and is released when the land is tilled

10. Nitrous Oxide Stays in the atmosphere for 120 years
Has a heat trapping potential 296 times greater than carbon dixide

11. Other GHG’s Chlorofluorocarbons CFC’s – destroy the ozone layer
They are now banned
Were used in aerosols, refrigerants
Hydro fluorocarbons – used to replace CFCs
Used in fire extinguishers, air conditioners, foam blowing and as other propellants
Ongoing debate s to restrict use of these