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=YdYH8m6HOCo

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 EnvironmentPros

• 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 EnvironmentPros

• 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 EarthThe 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 PollutantsDefinition:

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