1. Human Impact

2. Human Population Growth

3. Human Population Growth
Total
Human Population
Compared to past centuries, the human population is now growing at exponential rates!!
Due to: Higher birthrates; Better medical care/sanitation ; Better nutrition/food supply; Higher survivorship/ longer life expectancy.

4. Overhunting: extinct/endangered
bison
Black rhino
whales
Dodo bird

5. Overhunting
For most of human history, food was obtained through hunting. This led to the extinction of many species. Examples) North America – Woolly Mammoth, Saber toothed tigers, Giant ground sloth.

6. Importation of Organisms Invasive Species: those that are not native to an area. They cause major problems to ecosystems b/c they can easily out-compete native organisms; have no predators.
Japanese beetle
Gypsy moth

7. INVASIVE SPECIES
More examples: Rabbits in Australia, New Zealand (from Europe)
Fish like the Northern Snakehead in US Great Lakes (from Asia)

8. Exploitation Taking advantage of wildlife for financial gain.
Example) Overfishing – by 1990, Cod fish were almost completely gone from the world’s oceans
Taking advantage of wildlife for financial gain.
Elephant ivory tusks at market!

9. Poor Land Use Management
Over cropping
Overgrazing
No cover-crops (no crop rotation)
Drain wetlands
Urbanization
Sprawl – Think LA or Las Vegas!

10. Desertification: An example of poor land use management
Due to overgrazing, overfarming and drought, once productive areas have turned into desert.

11. Technological Oversight
The rapid technological advances in the last century have contributed to unforeseen levels of…
Fossil Fuel Emissions
Solid Wastes
Water Pollution
Evidence suggests that
climate change may be,
in part, related to human
activities that add
greenhouse gases to the atmosphere.
Herbicides-contaminate water supply
Pesticides-DDT disrupting the food chain

12. CO2 Emissions by Nation

13. Positive Aspects (of human actions)
Recycling programs
Population control
Legislation: The Kyoto Protocol – An international agreement to reduce Carbon emissions.
Improved farming

14. Attempts to maintain BIODIVERSITY in entire ecosystems.
Species Preservation
Attempts to maintain BIODIVERSITY in entire ecosystems. .
Zoos, captive breeding programs (Panda Bear).
Wildlife Refuges
Game Laws
National Parks
Endangered Species Act

15. Biological Control vs. Toxins
Using natural solutions to get rid or nuisances or problems
Use of sex hormones by trapping or immuno-contraception
Natural predators/parasites
Example : the use of petroleum-eating-bacteria to clean up oil spills.