3. Contents of the atmosphere
• Water vapor, is found in the atmosphere , and it ranges from 0% to
7% of the air.
• Another important gas is ozone ,a form of oxygen that absorbs the
harmful UV radiations from the sun .
• Ozone in the atmosphere helps protect life at earth’s surface from
the harmful effect of UV radiation.
6. Green house gases
• Green house gases are: Nitrous oxide, methane & CO2.
• Theses gases are very important to Earth as they trap the sun’s heat,
keeping our Earth warm .
• If the percentage of these gases increase, more heat will be trapped
in our Earth causing the temperature of Earth to rise “Global
warming”.
• Smoke of cars & factories & deforestation “cutting down trees” cause
an increase in the percentage of green house gases which results in
global warming.
