1. Global Issues
Biology CH 6

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

3. Environmental Problems CAUSED by HUMANS
Rapid population growth
More humans = more needs
We Need Food, Water, Shelter
All resources come from the environment

4. Pollution
Humans are increasing the levels of pollution in the environment
Causes cancer in humans and animals
Leads to the extinction of many species

5. Atmospheric Pollution
Increase in carbon dioxide pollution caused by burning fossil fuels
Global temperatures are increasing
Polar ice caps are melting and Sea levels are rising
Holes in atmosphere are allowing in more ultraviolet light  leads to mutations (skin cancer)

6. Oceanic Pollution
Eutrophication occurs when excess nutrients run off into the environment
Examples: Chemical and oils spills

7. Biological Magnification
Occurs when toxic chemicals accumulate in the tissues of organisms
Example: (DDT) dichlorodiphenyltrichloroethane is a pesticide used to kill insects, but has negative effect on birds and other organisms

8. The Value of Biodiversity
Why is biodiversity important?

9. The Value of Biodiversity
Total of all the genetically based variation in all organisms in the biosphere is called biodiversity
Types of biodiversity:
Ecosystem diversity (variety of habitats & communities)
Species diversity (1.8 million species & 30 million yet to be discovered)
Genetic diversity (genes present in a species)

10. Problem: Biodiversity Crisis
More species are going extinct now than in the past 100 thousand years

11. HUMANS Threat BIODIVERSITY
By:
Altering habitats  Deforestation & Habitat fragmentation (clear land for farming, housing decreases biodivesity)

12. HUMANS Threat BIODIVERSITY
By:
Overharvesting  killing wild organisms at a rate greater than the population can replenish

13. HUMANS Threat BIODIVERSITY
By:
Introducing invasive species  non-natives species compete for food and space

14. HUMANS Threat BIODIVERSITY
By:
Releasing pollution into food webs  biological magnification (Pesticides & Acid Rain)
Trying to “fix it”
Farmers using less pesticides
Alternative energy sources are being looked at.

15. HUMANS Threat BIODIVERSITY
By:
Contributing to climate change  global warming
Trying to “fix it”
Need to buy cars with good gas mileage, find alternative energy sources, protect forests (natural CO2 absorbers)

16. HUMANS Increase Biodiversity
Wildlife protection of species
Researching the needs of organisms and their interactions
Preserving forest and wetland habitats and ecosystems Re-introduction of a native species will increase biodiversity

17. Sustainable Development
What is the relationship between resource use and sustainable development?

18. Sustainable Development
Using natural resources in a way that does not cause long-term environmental harm is called sustainable development
causes no long-term harm to the soil, water, and climate on which it depends
consumes as little energy and materials as possible.
flexible enough to survive environmental stresses like droughts, floods, and heat waves