1. Impacts on the Atmosphere
What are some types of air pollution?
How are global warming and the carbon cycle related?
How does air pollution affect human health?
What actions help prevent air pollution?

2. Importance of Clean Air
Your body, and the bodies of other animals, uses oxygen in air to produce some of the energy it needs.
The air you breath must be clean or it can harm your body.

3. Types of Air Pollution smog acid precipitation
chlorofluorocarbons (CFCs)
carbon monoxide

4. Types of Air Pollution (cont.)
Photochemical smog forms when nitrogen and carbon compounds in the air react in sunlight.
Ozone close to the ground is a major component of smog.

5. Types of Air Pollution (cont.)
Acid precipitation is rain or snow that has a lower pH than that of normal rainwater.
Acid precipitation forms when gases containing nitrogen and sulfur react with water, oxygen, and other chemicals in the atmosphere.
Many living things cannot survive if the pH of water or soil becomes too low.

6. Types of Air Pollution (cont.)
The mix of both solid and liquid particles in the air is called particulate matter.
Solid particles including smoke, dust, and dirt enter the air from natural processes and human activities, such as burning fossil fuels.

7. Types of Air Pollution (cont.)
Appliances, such as air conditioners and refrigerators made before 1996, contain chlorofluorocarbon (CFC) coolants.
In the atmosphere, CFCs thin the ozone, allowing more UV rays to reach Earth’s surface.

8. Breathing carbon monoxide, a gas released from vehicles and industrial processes, reduces the amount of oxygen that reaches the body’s tissues and organs.
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9. Global Warming and the Carbon Cycle
An increased concentration of carbon dioxide in the atmosphere can lead to global warming, an increase in Earth’s average surface temperature.
Burning fossil fuels releases carbon dioxide into the atmosphere.

10. The Carbon Cycle

11. Global Warming and the Carbon Cycle (cont.)
Warmer temperatures can cause ice to melt, making sea levels rise, which can cause flooding along coastal areas.
Warmer ocean waters could lead to an increase in the intensity and frequency of storms.

12. The greenhouse effect is the natural process that occurs when certain gases in the atmosphere absorb and reradiate thermal energy from the Sun.

13. Health Disorders
Air pollution can cause respiratory problems, including triggering asthma attacks.

14. The Air Quality Index (AQI) is a scale that ranks levels of ozone and other air pollutants.

15. Positive Actions
Countries around the world are working together to reduce air pollution.
In the United States, the Clean Air Act, which was passed in 1970, sets limits on the amount of certain pollutants that can be released into the air.

16. Positive Actions (cont.)
Using renewable energy resources such as solar power, wind power, and geothermal energy reduces air pollution.
People can purchase more energy-efficient appliances and vehicles, such as hybrid cars, which emit less pollution.