1. CHAPTER 12 People and Their Needs
People must be
“emancipated from nature”
“the negation of nature is
the way toward happiness”
John Locke

2. Section 12.1 A Portrait of Earth
The Earth is a series of systems and connections
Ecosystems are affected by many factors:
Climate (the interaction between ocean, air and land)
Circulation (movement of air and water)
Plate Tectonics (movement of the Earth’s land mass)

3. Section 12.1 A portrait of Earth
Earth can also be viewed in terms of matter and energy:
For matter the Earth is a closed system
This means only tiny amounts of matter leave or join the Earth
For energy the Earth is an open system
This means that the Earth gets a huge amount of energy from the sun – some is released as heat
An open energy system allows large amounts of energy from the sun to be absorbed by the atmosphere, lithosphere and hydrosphere Earth. Then the Earth can radiate excess energy away from the planet as heat into the hydrosphere and atmosphere.
The closed system of matter allows only a very tiny amount of matter (rock, soil) into the Earth three systems and an equally small amount out of the Earth.

4. Earth Systems are Interconnected
2004 EARTHQUAKE/TSUNAMI
IN THE INDIAN OCEAN
Plate Tectonics

5. Earth Systems are Interconnected
Deep Ocean Zone Earthquake
and Tsunami - Japan 2011
Plate Tectonics

6. Section 12.1 The Gaia Hypothesis
Proposed in 1972 by James Lovelock a British scientist
States: The Earth is a single, living organism that regulates itself to maintain life.
James Lovelock proposed that we use the native people’s view of Earth as a way to take account of the whole planet and not just Earth’s individual systems or areas.

7. Section 12.2 Human Societies
Three Types of Human Societies:
Hunter-gatherer – nomadic people that hunt and gather naturally growing food.
Agricultural – grows crops, stay in one place
Industrial – produces food and other products using machines - requires large amounts of energy and resources
The earliest way people survived as a group was to roam the land trying to find as much food as they could. When that area’s food was used up, they moved on to a new area looking for more food.

8. 12.2 Hunter-Gatherer Society
Nomadic – travel to where food can be found – never stay in one place
Gather naturally growing plants and hunt for whatever animals they can find
Low population numbers
Have little or no impact on the environment
Can still be found in remote areas untouched by modern civilization
Hunter-gatherers did not require much energy or resources from the Earth. Their population size was small due to the limits of available food supplies and the amount of time the people had to spend getting their food

9. 12.2 Agricultural Society
10,000 to 20,000 years ago people in Southeast Asia and Africa began to farm
For the first time, they planted crops and raised animals for food
This caused two main changes:
1. people settled in one place
2. people found work within their society

10. 12.2 Agricultural The most important invention was the plow
The plow helped people plant more and produce more food,
More food meant more people Human population grew
Modern agriculture caused many environmental problems including:
increase land and chemical use,
soil depletion,
water contamination,
increase in food contamination

11. 12.2 Industrial Society
The human population faced change again in the late 1700’s
Production of food and everyday needs switched from skilled individuals to machines
Machines need much more energy and raw materials to produce products
Major damage to the environment began with the use of machines

12. Industrial Society Positive Scientists improved crops
Medical discoveries allowed people to live longer
More food and medical advances allowed the human population to grow even more
Negative
Increased use of energy
Increased use of natural resources
Increased population
Rapid increase in environmental damage
Air, land and water pollution
Raw materials are running out

13. Characteristics of Human Societies
Hunter-Gatherer
Agricultural
Industrial
Lifestyle/Technology
Use page 192
Table 12.1
Resource Use
To complete
This chart
Environment knowledge
Human health
Environmental impact
Energy Use

14. 12.3 Sustainable Development
Frontier Ethic
Sustainable Development
Humans are separate from Nature.
1) Resources are unlimited and here for our use.
2) Humans do not need to obey natural laws.
Our success/failure is measured by our control over the natural world.
Meets the current needs of society without limiting the way future generations meet their needs.
1) Resources are limited and not all to be used exclusively by humans.
2) Humans are part of the living Earth and must obey natural laws.
3) Human success means living in harmony with nature.

15. Sustainable Development
Frontier Ethic
Sustainable Ethic
1) Earth’s resources is limited by size and content.
2) Humans have carrying capacities and limiting factors that control our population just like any other organism.
3) Each human measures their success differently with respect to their environment.
Indefinite frontier ethic can not be successful.
1) Materials needed to build societies are limited.
2) Materials that can regenerate like wood or livestock are called renewable resources.
3) Materials that can not regenerate like oil and minerals are called non- renewable resources.
Successful societies will concentrate on using conservation and renewable resources.