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 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.

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

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