1. What is Human Impact?

2. Ecology is the study of the interactions of organisms with its environment.
Biodiversity is the variety of life in an area; # of species in an area

3. Population Growth
Populations grow when birth rate exceeds rate of mortality. Carrying capacity of humans is still unknown

4. Humans are part of the Earth's
ecosystem.  
Human activities can either deliberately or inadvertently alter the balance of an ecosystem.  

5. How do human activities affect the environment?
What do you Think???
How do human activities affect the environment?

6. Human impacts on the Environment
Global warming
is a slight increase in the earth’s average temperature.
Use of machinery by humans seems to be increasing CO2 levels in the air.
CO2 prevents heat from escaping, causes slight world wide temperature increases

7. Global Changes in the Atmosphere
Greenhouse effect: When heat from the sun bounces of the earth’s surface some of it is trapped in the atmosphere by greenhouse gases.
-Without it the earth’s surface would be too cold to support life.
Too many greenhouse gases (mainly carbon dioxide) have been released into the atmosphere trapping in too much heat.
Global Changes in the Atmosphere

8. Causes of Global Warming
The major cause of global warming is the burning of fossil fuels. When fossil fuels are burned they release carbon dioxide.
growth of the human population (all organisms release carbon dioxide)
Deforestation (Plants remove carbon dioxide from the atmosphere by photosynthesis).

9. The Effects of Global Warming
Changes in global climate patterns.
The organisms that live in some biomes may not be able to survive.
Changes in climate patterns could also reduce the world’s food supply.
Melting of the polar ice caps would increase sea level, leading to the flooding of coastal habitats.

10. need for space, farmland, housing, roads
Deforestation
Caused by demand for wood products,
need for space, farmland, housing,
roads
Deforestation causes habitat loss ---Animals and plants are forced into
confined areas

11. Habitat Loss

12. Habitat Fragmentation

13. Caused by aerosol chemicals called chlorofluorocarbons (CFCs) CFC’s
Ozone depletion
Caused by aerosol chemicals called
chlorofluorocarbons (CFCs)
CFC’s
-Escape into atmosphere, reacts breaking down the ozone (O3, a protective atmospheric layer)
-UV rays penetrate the atmosphere and cause harm to many organisms

14. “HOLE” in the ozone (O3)

15. Commercial Fishing be harmful to environment in many ways
Fishing activities
Demand for fish and shellfish
Commercial Fishing be harmful to environment in many ways

16. Invasive species (EXOTIC SPECIES)
introduced by people accidentally or intentionally
Can cause problems if no natural enemies are
present
-Cane toad was introduced to Australia to control cane beetles, pest insects that destroy sugar cane crops

17. kudzu (southeastern U.S)

18. Burmese python (Florida Everglades)

19. Zebra mussels

20. Importance of the Environment
Biodiversity = Many different types of organisms
Organisms
depend upon one another
Interfering with one
Organism can have a
Ripple effect to many
w/in the habitat

21. Importance of the environment
Natural resources:
Non-renewable includes fossil fuels (petroleum, coal, oil)
Renewable includes animals, plants, water, wind, etc.
even renewable resources can run out

22. Importance of the Environment
Natural resources
Renewable energy sources include wind power, geothermal energy, ocean currents

23. Pollution
Pollution is any undesirable factor added to the air, water, or soil.
Smog is one type of air pollution.
Acid rain is caused by fossil fuel emissions

25. Acid Rain
-Any precipitation that has a lower pH (more acidic) than normal.
-Formed when sulfur and nitrogen compound released into the atmosphere combine with water vapor and create sulfuric and nitric acids.
-The sulfur and nitrogen compounds are released when fossil fuels are burned.

26. If acid rain can destroy rock, imagine what it can do to a fragile fish egg.

27. Effects of Acid Rain
Damages the leaves of trees and can eventually lead to the death of the tree.
Lowers the pH of lakes and streams, which can kill the organisms in the lake or stream including producer organisms like algae.
It can also kill the eggs of some fish, and sterilize some fish.
Some lakes have been so acidic that nothing lives in them.

29. Solutions to Decrease Acid Rain Levels
Conserve energy (turn off lights, computer, and TV’s when not in use, turn down heat when no one is home and at night, hang clothes to dry, decrease time in the shower, etc.)
Use alternate energy sources (nuclear, solar, wind, or hydroelectric power)
Carpool, walk, or ride a bike when possible.
Burn cleaner coal
Place scrubbers (filters) on smoke stacks that remove the sulfur and nitrogen compounds.

30. Water Pollution
water can be polluted with human sewage, pesticides, herbicides, fertilizers, and toxic wastes (poisons) from factories.
As a result the abiotic conditions of the water change. For example, changes in temperature, pH, and oxygen content.

31. Oil pollution

33. Pollution: Agricultural Homes Industry DDT Fertilizers
Animal wastes (nitrogen)
Homes
Strong cleaning agents
Industry
Toxic gases and wastes
Acid rain

34. Biomagnification

35. Biomagnification causes accumulation of toxins in the food chain.
-Pollutants can move up the food chain.
predators eat contaminated prey
pollution accumulates at each stage of the food chain
Top consumers, including humans, are most affected.

36. The Green Revolution
The application of science to increasing agricultural productivity, including the breeding of high-yield varieties of grains, the effective use of pesticides, and improved fertilization, irrigation, mechanization, and soil conservation techniques.