1. Human Impact on the Environment:
A look at the ozone layer, global warming, acid rain, deforestation, and vehicle emissions…

2. The Ozone Layer
Ozone occurs naturally in the layer of our atmosphere called the stratosphere.
The ozone layer protects us from ultraviolet light.

3. Human made chemicals called CFCs are damaging the ozone layer.
Ozone Depletion
Human made chemicals called CFCs are damaging the ozone layer.
CFCs are found in…
Refrigerator coolants
Air conditioner coolants
Styrofoam
Propellants in spray cans

4. The ozone layer is decreasing over both the north and south poles.
More ultraviolet light means…
Problems with skin cancer
Cataracts
Faster aging of skin

5. Greenhouse Effect
CO2, Methane and water vapor NATURALLY create a layer that traps heat close to the earth to maintain Earth’s temperature range
This is NORMAL, BUT….

6. Global Warming
The more CO2 and Methane there is, the more heat gets trapped!

7. Because of us, the greenhouse gases in the atmosphere increase over time causing temp to rise.

8. What’s a degree or two??
To you, nothing. To the polar ice caps, a lot!!
If they melt, they add tons of freshwater to the salt water oceans.
This change in salinity can change the flow of water

9. What’s a degree or two??
We owe our temperate climate to the northern flow of warm waters of the equator
No warm water, no warm weather, North America’s climate may be dramatically colder…. Arctic?

10. Acid Rain ph of pure water = 7 pH of normal rain = 5.4 – 7
Mixes with CO2 to form a mild acid
pH of acid rain < 5.4

11. Acid Rain
When fossil fuels are burned, they release sulfur and nitrogen oxides which form sulfuric and nitric acid when they mix with water.

12. Acid Rain
The pH of lakes, soil, plant life is lowered. Homeostasis may be destroyed!

13. A Beautiful Sunset?
A colorful sunset like this may be caused by dust and pollutants in the atmosphere…

14. The acid rain changes the pH of ecosystems, making the environment too extreme for plants and animals.

15. Deforestation
Forests around the world are being cleared at an alarming rate.

16. Deforestation involves clearing trees from an area without replacing them.

17. Today, the problem of deforestation is especially disturbing in the tropical rain forests.
Also increases CO2 if trees are cleared by burning!
Don’t even benefit from the wood!

18. Vehicle Emissions Automobile emissions are responsible for…
at least 1/2 of all urban air pollution.
about 1/4 of all carbon dioxide released into the atmosphere.

19. Other Sources of Air Pollution
Industrial emissions
Fossil Fuel Combustion
Livestock

20. Endangered species and Extinct Species

21. Why?
Development: leads to loss of habitat; organisms are force to move somewhere where they are not suitably adapted
Hunting: obvious….
Introduction of new species: We bring in something that doesn’t belong. Maybe it out competes, or preys on other species.