Our Environment Through
Time
Periods of Human History that
Impacted the Environment
1) Hunter - Gatherers
2) Agricultural Revolution
3) Industrial Revolution
Hunter - Gatherers
Definition:
People who obtain food by collecting plants
and hunting wild animals
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)
Hunter Gatherers Clip
http://www.youtube.com/watch?v=YdYH8m6
HOCo
Agricultural Revolution
Definition:
Growing, breeding, and caring for plants and
animals that are used for food, clothing,
housing, transportation and other
purposes
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
Industrial Revolution
Definition:
Shift from energy sources such as animal
muscle and running water to fossil fuels
such as coal and oil
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)
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
Industrial Revolution Clip
http://www.youtube.com/watch?v=6fUBXe7_
7Bg
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.
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
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
Problems with Earth Being a
Closed System
1) Limited natural resources
2) Wastes produced more quickly than we
can dispose of them
3 Main Environmental Problems
1) Resource Depletion
2) Pollution
3) Loss of Biodiversity
Resource Depletion
Definition:
Any natural material used by humans that is
depleting
2 Types of Natural Resources:
1) Renewable
2) Nonrenewable
Renewable Resources
Definition:
A resource that can be replaced naturally
very quickly
Examples:
Soil
Trees
Nonrenewable Resources
Definition:
A resource that renews at a slower rate than
it is consumed
Examples:
Minerals
Fossil Fuels
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
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
Nondegradable Pollutants
Definition:
Pollutants that CANNOT be broken down by
natural processes
Examples:
Mercury, lead and some types of plastics
Loss of Biodiversity
Biodiversity
Definition:
Number and variety of species that live in an
area
Problem:
Extinction of species due to humans