1. Our Environment Through Time

2. Periods of Human History that Impacted the Environment
1) Hunter - Gatherers
2) Agricultural Revolution
3) Industrial Revolution

3. Hunter - Gatherers Definition:
People who obtain food by collecting plants and hunting wild animals

4. Hunter - Gatherer's Impact on the Environment
1) Overhunting caused some species of animals to become extinct
2) Destruction of trees and grass (ex: burned down trees to make it easier to hunt bison)

5. Hunter Gatherers Clip

6. Agricultural Revolution
Definition:
Growing, breeding, and caring for plants and animals that are used for food, clothing, housing, transportation and other purposes

7. Agricultural Revolution's Impact on the Environment
Pros
Increased human population
Created domesticated crops out of wild plants
Cons
Habitats were destroyed to create farmland
Soil became infertile due to over use

8. Industrial Revolution
Definition:
Shift from energy sources such as animal muscle and running water to fossil fuels such as coal and oil

9. Industrial Revolution's Impact on the Environment
Pros
Less demand for land to farm
Cons
Air pollution from fossil fuels
Invention of non biodegradable materials (plastics)

10. Industrial Revolution's Impact on Society
1) Less expensive to purchase goods
2) Motorized vehicles allowed goods to be shipped across greater distances
3) Improved sanitation, nutrition and medical care

11. Industrial Revolution Clip

12. With a partner decide what type of society we live in today (Hunter - Gatherer, Agricultural, or Industrial). List 5 examples that support your choice. Discuss your responses as a class.

13. The Earth is a CLOSED SYSTEM
Planet Earth
The Earth is a CLOSED SYSTEM
The following things CANNOT be added to the Earth or its atmosphere
Water
Air
Land
Elements
Ozone Layer

14. Planet Earth Continued
ENERGY is the only thing that can enter and leave the Earth
2 Forms of Energy:
1) Sunlight into Earth
2) Heat leaving Earth

15. Problems with Earth Being a Closed System
1) Limited natural resources
2) Wastes produced more quickly than we can dispose of them

16. 3 Main Environmental Problems
1) Resource Depletion
2) Pollution
3) Loss of Biodiversity

17. Resource Depletion Definition:
Any natural material used by humans that is depleting
2 Types of Natural Resources:
1) Renewable
2) Nonrenewable

18. Renewable Resources Definition:
A resource that can be replaced naturally very quickly
Examples:
Soil
Trees

19. Nonrenewable Resources
Definition:
A resource that renews at a slower rate than it is consumed
Examples:
Minerals
Fossil Fuels

20. Pollution Definition:
An undesired change in air, water, or soil that adversely affects the health, survival, or activities of humans or other organisms
2 Types of Pollution:
1) Biodegradable Pollutants
2) Nondegradable Pollutants

21. Biodegradable Pollutants
Definition:
Pollutants that CAN be broken down by natural processes
Examples:
Human sewage, Food wastes
* CAN BE A PROBLEM if they accumulate quicker than they can be broken down

22. Nondegradable Pollutants
Definition:
Pollutants that CANNOT be broken down by natural processes
Examples:
Mercury, lead and some types of plastics

23. Loss of Biodiversity Biodiversity Definition:
Number and variety of species that live in an area
Problem:
Extinction of species due to humans