The atmosphere consists mainly of nitrogen (78%) and oxygen (21%), and also contains smaller amounts of water vapor, carbon dioxide, and ozone. It is held in place by Earth's gravitational force and is densest closest to the surface, decreasing in density with altitude. The atmosphere functions to provide oxygen for respiration, nitrogen for plant growth, carbon dioxide for photosynthesis, protection from UV radiation, and moderation of temperature ranges. Human activities such as burning fossil fuels and deforestation release greenhouse gases like carbon dioxide and methane that are absorbing more heat from the sun, increasing atmospheric temperatures and causing sea levels to rise as ice melts.

1. Mrs. F. J. Beukes
Hoërskool Generaal Hertzog

2. THE ATMOSPHERE
 Consist of: force.
 Nitrogen (78%)  Most dense closest to Earth’s
 Oxygen (21%) surface.
 Water vapour
 Density decreases with height
 Carbon dioxide
above surface.
 Ozone
 Held in place by gravitational
FUNCTIONS:
 Source of oxygen – respiration
 Contains nitrogen
 Protein production
 Plant growth
 Contains carbon dioxide – photosynthesis
 Protection against UV radiation
 Decrease temperature range

3. GREENHOUSE EFFECT
Human activities release carbon dioxide into atmosphere:
•Combustion of fossil fuels
Greenhouse gases in atmosphere absorb INFRARED
•Industrial processes sun:
radiation from the
•Deforestation
•Carbon dioxide – CO2
•Burning of wood 3
•Methane – CH
•CoalWater vapour – H2O
• mines consequences:
Negative
•Waste •Atmospheric temp. RISE
•Ozone – O3
disposal
• from
•ManureSea level rise – ice at poles melt
•CFC’s animals
•Wind
•Air pollution patterns change
•containers/fridge coolants
•Aerosol Existing species are forced out of natural habitat
•Coral beds are destroyed
•Agricultural yields are disturbed
•Ideal conditions for breeding insects

4. WHAT?
•Air polluted with gases…
•…SO2, CO2 and Nox
…gases react with rain
and dilute acids form.
CONSEQUENCES:
•Lakes/rivers become
acidic
•Influence tree/plant
growth
•Destroy metal
structures/buildings

5. Nitrogen 2. Source of oxygen for respiration.
(78%) Contain nitrogen for plant growth.
Contain carbon dioxide for
Oxygen
photosynthesis.
(21%)
Offer protection against UV
Water radiation.
vapour Decrease temperature range.
Atmosphere 3.1 Oxygen
Carbon 3.2 Nitrogen
dioxide 3.3 Carbon dioxide
3.4 Ozone layer
Ozone 3.5 Greenhouse effect
3.6 Carbon dioxide, Sulfur dioxide and
Nitrogen oxides.
Other gases