Greenhouse Gases GHG’s

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

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

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

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

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

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 50-200 yrs

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

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

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

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