People And Their Needs

Chapter 12

12.1 A Portrait of Earth• Biomes – The interactions among

organisms and abiotic factors give rise to distinct ecosystems.

12.1 A Portrait of Earth Systems and Connections

• Climate is determined primarily by the interaction of air and water.

• Physical laws govern Earth’s systems through matter and energy.

• Ocean circulation, plate tectonics, and global temperature changes all result in dramatic changes in ecosystems.

12.1 A Portrait of Earth Systems and Connections

• Earth is a closed system when it comes to matter. Only a tiny bit enters in and leaves.

• Earth is an open system with respects to energy due to the exchange among the sun, Earth, and space.

• The sun’s energy powers ocean currents, cloud formations, and plant growth.

12.1 A Portrait of Earth Perceptions of Eart

• Gaia hypothesis states that Earth functions like a single, living organism that regulates itself to maintain life.

• Earth is thought of as a living organism.

• Gaia hypothesis disagrees with the views of most modern industrial societies.

12.2 Human Societies• Fully modern Homo sapiens first evolved

from ancestral humans about 35000 years ago.

• They were intelligent, artistic (painters), and handy (intricate tools).

12.2 Human SocietiesHunter-Gatherer Societies

• A society in which people gather natural food, hunt, and are nomadic.

• Small impact on the environment because of low population density which allows the environment to regenerate.

• They don’t drain the resources!

12.2 Human SocietiesAgricultural Societies

• A society in which crops are grown and people have specialized roles.

• The early, rapid growth rate was a result of an increased food supply.

• The invention of the plow led to the expansion of the food supply.

12.2 Human SocietiesAgricultural Societies

• As farming became more productive, more people were able to manufacture products.

• Societies that fell like the Babylonian Empire were a result of unwise land-use practices resulting in desertification.

12.2 Human SocietiesIndustrial Societies

• A society in which the production of food and other products is performed by machines, demanding large amounts of energy and resources.

• Machines replaced craftspeople.

12.2 Human SocietiesIndustrial Societies

• The increase of industrialization was accompanied by increased use of fossil fuels.

• Food Supply, Human Population and Manufactured Goods all increased during this time.

12.3 Sustainable Development

• Resource – Water, Wind and Sunlight

• Human populations are subject to natural controls.

– Ex. Temperature, Precipitation, Crops, Oxygen

12.3 Sustainable DevelopmentThe Frontier Ethic

• Founded on the assumption that human society is separate from nature.

• Not an Environmentally Friendly Ethic!

• Examples of Frontier Ethic activities would include clear cutting forests, building dams, and draining wetlands.

12.3 Sustainable DevelopmentThe Sustainable Development Ethic

• An ethic that meets current global human needs without limiting the ability of future generations to meet their own needs.

• Renewable Resources – A resource that regenerates quickly. (Ex. Water, Wood,Sun)

• Nonrenewable Resources – A resource that cannot regenerate quickly. (Ex. Oil, Ores)– They are running out!!!