1. 6.1 A Changing Landscape

2. The Effect of Human Activity
How do our daily activities affect the environment?

3. Living on Island Earth
Like all organisms, humans affect the environment when we obtain food, eliminate waste products, and build places to live.
Human activity has altered roughly half of all the land that’s not covered with ice and snow.
Might be reaching carry capacity at 7 billion.

4. Agriculture
Modern agricultural practices allowed farmers to double world food production over the last 50 years.
Monoculture, is the practice of clearing large areas of land to plant a single highly productive crop year after year.

5. Cities and Suburbs

6. Industrial Growth
The conveniences of modern life require a lot of energy to produce and power.
Industries have traditionally discarded wastes from manufacturing and energy production directly into the air, water, and soil.

7. How can we prevent the overuse of resources?
Sustainable Development

8. Environmental science
… can help us avoid mistakes made by past civilizations. The lesson of Easter Island: people annihilated their culture by destroying their environment.

9. Sustainable Resource Use
Using natural resources in a way that does not cause long-term environmental harm is called sustainable development.
Cause no harm and use least amount of energy as possible
Wind farms, solar energy, hybrid cars, etc.

10. Natural resources: vital to human survival
Natural resources = substances and energy sources needed for survival
Renewable resources:
Perpetually available: sunlight, wind, wave energy
Renew themselves over short periods: timber, water, soil
These can be destroyed
Nonrenewable resources: can be depleted
Oil, coal, minerals

11. 6.2 Using Resources Wisely

12. Soil Erosion Soil erosion is the removal of soil by water or wind.
Ex: dust bowl of the 1930s

13. How can farmers prevent soil erosion?
Crop Rotation
Leaving stems/roots of previous plant
Alter shape of land

14. Soil Erosion
Farming, overgrazing, seasonal drought, and climate change can turn farmland into desert -desertification.
Roughly 40 percent of Earth’s land is considered at risk for desertification.

15. Soil Erosion
Deforestation, or the loss of forests. Half of the world’s old-growth forests have been lost to deforestation.
Healthy forests hold soil in place,, absorb carbon dioxide, and help moderate local climate.
Succession may occur after cutting

16. Water Pollution
A pollutant is a harmful material that can enter the biosphere.
Only 3 percent of Earth’s water is fresh water—most of that is locked in ice at the poles.
Used for drinking water, industry, transportation, energy, and waste disposal

17. Biological magnification Increase in concentration of a certain substance throughout a food chain. Ex: Mercury

18. What are some forms of air pollution?
Smog
Acid Rain
Greenhouse gases
Particulates

19. Smog
Smog is a gray-brown haze formed by chemical reactions among pollutants released into the air by industrial processes and automobile exhaust.

21. Acid Rain

22. Greenhouse Gases

23. Particulates