1. Our Impact on the Land

2. Populations Populations
All the individuals of one species living in the same area
Population Explosion: Earth’s population is increasing rapidly
Medicine, clean water, and better nutrition, have lowered the death rate
Number of births has increased because more people are living to child bearing age

3. Population By 2100, Estimated population of Earth is 11 Billion
Almost Twice what it is now

5. Population Pyramids

6. How Many People Can the Earth Hold?
Earths Carrying Capacity
Largest Number of individuals of particular species the environment will support
Limited By
Space
Resources

7. How do we affect the Environment?
Electrical Use
Burning Fossils fuels emits pollutants
Environment changes when fossil fuels are mined
Eating Food
It takes land to grow food
Use of chemical substances to grow food, can get into water supplies and threaten other species

8. Strip Mining

9. Affect the Environment
Plastics
Made from oil
Refining oil produces pollutants
Paper
Trees are cut down
Water and air pollutants are given off in the papermaking process
Garbage
Needs to be disposed somewhere

10. Paper Mill

11. Land Fills

12. Using Land
Farming
Feeds People, farmer’s try to grow more and better crops
Negative Affects of Farming
Chemical Fertilizers
Herbicides and pesticides

13. Using Land Positive affects of Farming
Organic Farming: natural fertilizers, crop rotation, biological pest controls
No Till Farming: Planting seeds between previous year’s stubble to save top soil
Contour Plowing: Rows are tilled across hills and valleys to capture water and soil

14. Organic Farming

15. No Till Farming

16. Contour Planting

17. Using Land Growing food for Livestock
Some believe it would be more efficient to use all the land to grow crops for people
Others believe using the land for cattle is important because people need meat and dairy products

18. Livestock

19. Using Land Source of Wood
Trees are cut down and used for lumber, fuel, and paper
Species become extinct each year due to the loss of forests, especially rain forest
Less vegetation may cause higher levels of carbon dioxide in the atmosphere
Local regions may receive less rainfall

20. Clear Cut

21. Selective Cutting

22. Using Land Developments
Buildings, Highways, office buildings, stores and parking lots
Paving prevents water from soaking into the soil
Instead it runs off into streams and sewers
Stream Discharge: volume of water flowing past a point per unit of time

23. Using Land
Pavement
In paved areas, heavy rainwater an lead to increased stream discharge, causing flooding
Paving prevents rainwater from refilling underground water supplies

24. Landfills Sanitary Landfills
Areas where daily garbage is deposited and covered with soil
Lined with plastic, concrete, or clay rich soil to prevent pollutants from leaking into soil or groundwater
Many materials do not decompose in landfills
As landfills fill up, new ones must be built

25. Sanitary Landfill

26. Wastes Hazardous Wastes
Wastes that are poisonous that cause cancer, or that can catch fire
In many states, they cannot be deposited in sanitary landfills
Some can be recycled
Phytoremediation: using plants to clean up the soil be removing metal from it

27. Phytoremediation

28. Hazardous Waste Landfill

29. Wastes Cont’d Enzymes Natural Preserves
From plant roots increase the rate that organic pollutants break down
Natural Preserves
Land that is set aside to protect it from environmental problems caused by people

30. Conserving Resources Conservation Ways to Conserve
The careful use of resources to reduce damage to the environment
Ways to Conserve
Reduce: Use less materials
Reusing: Finding another use for an item rather then throwing it away

31. Ways to Conserve Reusing Recycling
Composting: piling yard wastes where they can decompose gradually
If everyone in the country used composting, 20% less trash would be put in landfills
Recycling
Using materials again by converting used materials into new and useful products
These processes can save landfill space, reduce energy use and minimize the need to extract raw materials from Earth

32. Recycling

33. Composting