Air and Water

❁ Some sources of greenhouse gases are natural and some are man-made.

ome pictures about (Natural sources) for CO2, CH4 and H2O vapor: 

                                                  Decomposition of vegetation 

Forest fire (CO2) (CH4)

Evaporation from Ocean ( H2O )

❁ The amount of man-made water Vapor is insignificant compared to the amount of water vapor from natural sources. However, emissions of methane and carbon dioxide are contributing to the increase in global warming.

❁ Human activities are causing the release of large amounts of carbon dioxide. These activities include:  

• 1. Deforestation: 

Cutting down trees for fuel, farms, buildings and roads.

• 2. Increased use of energy  

(and so an increased use of fossil fuels).

❁ As the percentage of carbon dioxide in the atmosphere has increased, so in general has the Earth’s mean temperature.