1. All About the Air…

2. Is your head in the clouds?
Well, it is in the Atmosphere!

4. The Troposphere is where most of the gases and our weather are found
The Troposphere is where most of the gases and our weather are found. We live in this layer.
The Stratosphere has our ozone shield.

5. Let’s not forget…
Climate is the average weather patterns in an area over a long period of time - temperature and precipitation.
And…
Weather is atmospheric conditions the on a given day.

6. Ozone Form of oxygen with molecules made of 3 oxygen atoms.
The ozone shield protects us from harmful radiation because it absorbs most of the ultraviolet light from the sun.

7. Why do we need the atmosphere?
1. Protects living organisms from harmful UV radiation.
2. Warms the planet.
3. Supplies energy allowing photosynthesis to occur.

8. What is it made up of? Nitrogen (78%) Oxygen (21%)
Carbon Dioxide, Helium, Argon, Water Vapors & other substances. (1%)
Oxygen and carbon dioxide are the two most important gases in the atmosphere because they are used for photosynthesis and cellular respiration.

9. Air Pollution…bad stuff!!!
A substance that is present in the air in an amount that is undesirable or harmful to living things.
Air pollution can be in the form of solid, liquid, or gases.

10. Most air pollution is the result of human activity but pollutants also come from natural sources.
Examples: volcanoes, salt from ocean, pollen/pores from plants.

11. There’s more than one type!!!
Primary pollutant: put directly into the air by human activity
Examples : soot from
smoke stacks

12. Secondary Pollutant: formed when a primary pollutant comes into contact with other primary pollutants, or when naturally occurring substances, like water vapor, combine and a chemical reaction takes place.
Examples :ozone + nitrogen dioxide = NO2

13. Where is it all coming from?

14. 1. Vehicles -
The majority of air pollution comes from gasoline burned in motor vehicles.

15. Clean Air Act (1970)
gives EPA the authority to regulate automobile emissions.
catalytic converters clean exhaust before they exit a tailpipe
one effective way to reduce air pollution is to carpool.
use alternative forms of energy

16. 2. Industrial Air Pollution -
Most burn fossil fuels to get the energy they need. Causes huge quantities of oxides to be released.
Some industries produce volatile organic compounds (VOC’s) - form toxic fumes.

17. Controlling Air Pollution from Industries
Clean Air Act requires scrubbers or other pollution-control devices.
removes some noxious substances, moves gases through a spray of water that dissolves pollutants, and removes particulates.

18. 3. Smog - combination of smoke and fog.
Air pollution that hangs over urban areas and reduces visibility.
- results from chemical reactions involving sunlight, nitrogen oxides, and hydrocarbons.
Main Causes: pollutants released by cars and industries.
3. Smog -

19. What’s the damage?

20. Ozone depletion…
1. Causes mutations or death of cells near the surface of the body. (skin cancer)
2. Kills one-celled organisms that live near the surface of the ocean disrupting ocean food chains and reducing harvests.
3. Reduces # of producers and further increases the amount of carbon dioxide in the atmosphere.
4. Weakens the immune system, making the body more susceptible to diseases.
5. Increases the chances for cataracts and therefore blurred vision or blindness.

21. Acid Precipitation -
Highly acidic (pH < 5) precipitation that results from the burning of fossil fuels.
releases oxides of sulfur and nitrogen as byproducts.
Oxides combine with water in the atmosphere forming sulfuric acid and nitric acid, which falls as precipitation
can dissolve calcium carbonate in concrete and limestone (eats away historic monuments)

22. Greenhouse Effect - The atmosphere is like a greenhouse.
Sunlight heats the Earth
as the heat rises, some escapes into space
some heat is trapped by gases in the troposphere and warms the air

23. Greenhouse Gases – gases that trap and radiate heat Examples: water vapor, CO2, CFC’s, methane, nitrous oxides.

24. The most important greenhouse gases are water vapor (most abundant
The most important greenhouse gases are water vapor (most abundant!) and carbon dioxide.
Carbon Dioxide levels are increasing due to deforestation and combustion (the burning of fossil fuels).
Due to an overall increase in greenhouse gases, the average temperature of the Earth is increasing which is known as global warming.

25. CFCs… Chlorofluorocarbons
3 sources of CFC’s are refrigerators, air conditioners and styrofoam.
CFC’s are harmful because they destroy the ozone.
It is estimated that one chlorine atom can destroy as many as 100,000 ozone molecules.

26. Global Warming…
May cause oceans to absorb more heat energy making hurricanes and typhoons more common and more devastating.
Ocean currents may also change which will affect the Earth’s weather.
May also cause icebergs, glaciers, and the polar caps to melt causing a rise in sea level. This could also cover some coastal areas.

27. What can you do? What will you do?