1. Human Impact on the Environment

2. Biodiversity
The total of all the different species living in a given area.

3. Where do we find the greatest biodiversity?
The Rainforest !

4. Biodiversity = Stability
The greater the biodiversity the greater the stability of an ecosystem.

5. Threats to Biodiversity
A. Habitat destruction
B. Deforestation
C. Global Climate Change
D. Species Exploitation
E. Species Extinction

6. Biodiversity
Ecosystems will have a greater chance of maintaining equilibrium over a long period of time if they have
(1) organisms imported by humans from other environments
(2) a sudden change in climate
(3) a diversity of organisms
(4) predators eliminated from the food chains

7. Human activity damages the biosphere.
Over-Population, destruction of habitats for agriculture and mining, pollution from industry and transportation, and many other activities all contribute to the damage of the environment. Some of the destructive consequences of human activity are:

8. The Greenhouse Effect
The burning of fossil fuels and forests increases CO2 in the atmosphere.
Increases in CO2 cause more heat to be trapped in the earth's atmosphere.
As a result, global temperatures are rising.
Warmer temperatures raise sea levels (by melting more ice) and decrease agriculture output (by affecting weather patterns).

9. Ozone Depletion
The ozone layer forms in the upper atmosphere when UV radiation reacts with oxygen (O2) to form ozone (O3).
The ozone absorbs UV radiation and thus prevents it from reaching the surface of the earth where it would damage the DNA of plants and animals.
Various air pollutants, such as chlorofluorocarbons (CFCs), enter the upper atmosphere and break down ozone molecules.
CFCs have been used as refrigerants, as propellants in aerosol sprays, and in the manufacture of plastic foams.
When ozone breaks down, the ozone layer thins, allowing UV radiation to penetrate and reach the surface of the earth.
Areas of major ozone thinning, called ozone holes, appear regularly over Antarctica, the Arctic, and northern Eurasia.

10. Ozone Hole
These images of the ozone hole were taken by NASA between September 1981 and September 1999.

11. Acid Rain
The burning of fossil fuels (such as coal) and other industrial processes release into the air pollutants that contain sulfur dioxide and nitrogen dioxide.
When these substances react with water vapor, they produce sulfuric acid and nitric acid.
When these acids return to the surface of the earth (with rain or snow), they kill plants and animals in lakes and rivers and on land.

12. Desertification
Overgrazing and developing of grasslands that border deserts transform the grasslands into deserts.
As a result, agricultural output decreases, or habitats available to native species are lost.

13. Deforestation
Clear-cutting of forests causes erosion, flooding, and changes in weather patterns.
The slash-and-burn method of clearing tropical rain forests for agriculture increases atmospheric CO2, which contributes to the greenhouse effect.
Because most of the nutrients in a tropical rain forest are stored in the vegetation, burning the forest destroys the nutrients.
As a result, the soil of some rain forests can support agriculture for only one or two years.

14. Algal Blooms and Eutrophication
Phosphate pollution, stimulates algal blooms, or massive growths of algae and other phytoplankton.
The phytoplankton reduce oxygen supplies at night when they respire.
When the algae eventually die, their bodies are consumed by bacteria, whose growth further depletes the oxygen.
The result is massive oxygen starvation for many animals, including fish and invertebrates.
In the end, the lake fills with carcasses of dead animals and plants.
The process of nutrient enrichment in lakes and the subsequent increase in biomass is called eutrophication.
When the process occurs naturally, growth rates are slow and balanced.
With the influence of humans, the accelerated process often leads to the death of fish and the growth of anaerobic bacteria that produce foul-smelling gases.

15. Nutrient Enrichment
The worldwide increase in red tides ( dinoflagellates ) and other blooms of toxic algae in coastal ocean waters has been linked to nutrient enrichment coming from coastal rivers. Nuisance species such as these, in fresh water as well as coastal oceans, can increase and force out less tolerant species, resulting in a loss of aquatic biodiversity.

16. Sources of Nutrients
Several sources of nutrients are found in lakes and streams.
Some are from natural sources, but many stem from human activities.
Natural Sources.
Nutrients are present naturally in lakes and streams, but human activity has greatly
increased the amounts going into surface waters.
Low levels of nitrogen and phosphorus.
Sewage Treatment Plants.
Wastewater (or sewage) treatment plants are point sources of nutrients by virtue of the effluent
which they discharge directly to rivers and streams.
Household Detergents.
In the past, household detergents brought high loads of phosphorus to treatment plants,
which then were discharged with the effluent.
In the United States, however, laws restricting the phosphorus content of detergents
have produced markedly reduced phosphate levels.
Septic Systems.
Septic systems may contribute large amounts of nutrients, particularly if located close to the water.

17. Sources of Nutrients Sediment.
Sediment from excessive erosion is a nonpoint source that transports phosphorus in particles attached to soil.
Construction sites increase the amount of sediment reaching lakes and streams, bringing in large phosphorus loads.
Animal Manure.
Manure is a significant source of nutrient pollution in lakes and streams.
Manure from livestock, if not properly managed, can reach streams through runoff or from direct deposits by animals in the water.
Commercial Fertilizers.
Commercial fertilizers are a major source of both phosphorus and nitrogen.
Atmospheric Nitrogen.
Atmospheric nitrogen comprises about 78 percent of the air that humans breathe.
The burning of fossil fuels forms oxidized nitrogen compounds, which then reach the Earth when it rains or snows. In some parts of the United States, in particular the Northeast and the Upper Midwest, the so-called "acid rain" associated with these processes conveys large nitrogen loads to lakes and streams..

18. Air Pollution
Suspended Particles – made up of soot, smoke, dust and liquid droplets.
Associated health hazard: particles and soot exposure over a long period of time is related to a wide range of chronic respiratory illness such as asthma and chronic obstructive pulmonary diseases as well as worsening heart conditions and other conditions.
Nitrogen Dioxide – caused by fuel combustion, aerobic decomposition and nitrogenous fertilizers.
Sulfur Dioxide – produce by the combustion of fossil fuels, with motor vehicles and small and varied sources (such as boilers and stoves) contributing the most.
Associated health hazard: causes acid rain and can be extremely detrimental to the health of the young and elderly.

19. Water Pollution
Two types of water pollutants exist; point source and nonpoint source. 
Point sources occur when harmful substances are emitted directly into a body of water. 
The Exxon Valdez oil spill best illustrates a point source water pollution. 
A nonpoint source delivers pollutants indirectly through environmental changes.  An example of this type of water pollution is when fertilizer from a field is carried into a stream by rain, in the form of run-off which in turn effects aquatic life. 
The technology exists for point sources of pollution to be monitored and regulated, although political factors may complicate matters.
Nonpoint sources are much more difficult to control.  Pollution arising from nonpoint sources accounts for a majority of the contaminants in streams and lakes.

20. Examples of Land Pollution
Soil pollution is mainly due to chemicals in herbicides (weed killers) and pesticides (poisons which kill insects and other invertebrate pests).
Litter is waste material dumped in public places such as streets, parks, picnic areas, at bus stops and near shops.
Waste Disposal: the accumulation of waste threatens the health of people in residential areas.
Waste decays, encourages household pests and turns urban areas into unsightly, dirty and unhealthy places to live in.
U.S. Oil Field

21. Pollution
Some toxins, such as the pesticide DDT, concentrate in plants and animals.
As one organism eats another, the toxin becomes more and more concentrated, a process called Biological Magnification.

22. Dead Zones
Dead zones are low-oxygen, or hypoxic, areas in the world's oceans and lakes. Because most organisms need oxygen to live, few organisms can survive in hypoxic conditions. That is why these areas are called dead zones.

24. Dead Zones The formation of dead zones happens when:
Excess nitrogen enters body of water
Phytoplankton take up nitrogen during reproduction. With excess nitrogen in the water they will reproduce very rapidly. The population growth is called a plankton bloom.
Organisms in the plankton bloom die, sink, and decompose (biological pump)
The decomposition process requires consumption of dissolved oxygen, which takes away the supply of oxygen to other marine life, like fish, crab, shrimp and jellyfish
These creatures have to evacuate and find a new area if they want to survive, which creates dead zones. 
Physical factors that contribute to dead zones:
Warmer water means less dissolved oxygen; DO is much more soluble in cooler water
Warmer waters also increase metabolism of marine creatures, thereby increasing their need for oxygen
Warmer temperatures and increased runoff of freshwater will increase stratification of the water column, thus further promoting the formation of dead zones
Water circulation; in the summer the circulation isn’t as intense so DO doesn’t disperse as much

25. Reduction in Species Diversity
As a result of human activities, especially the destruction of tropical rain forests and other habitats, plants and animals are becoming extinct at a faster rate than the planet has ever previously experienced.
If they were to survive, scientists believe many of the disappearing plants could become useful to humans as medicines, foods, and industrial products.

26. One irreversible effect of both deforestation and water pollution on the environment is the
(1) extinction of species ( decrease in biodiversity )
(2) thinning of the ozone shield
(3) increase of atmospheric carbon dioxide levels
(4) decrease in renewable resources

27. Human activities have had a major impact on biodiversity
Human activities have had a major impact on biodiversity. Scientists cannot solve this problem alone. Concerned individuals need to be involved in restoring and maintaining biodiversity. Explain how a loss of biodiversity today can affect the survival of humans in the future. State one specific action that you as a student can take in your community to help maintain or increase biodiversity.

28. Which ecosystem is more stable a potato field or a forest? Why?

29. Renewable Energy Renewable Resources :
These are resources that can regenerate or replace themselves.

30. Renewable Resources
Tidal Power
Wave Power

31. Renewable Resources
Solar Power
Wind Power

32. Renewable Resources
Hydroelectricity
Geothermal Power

33. Renewable Resources
Biomass
Nuclear Power

34. Non Renewable Resources
A resource that can NOT be replaced or replenished by natural processes
Fossil Fuels

35. Non-Renewable energy Resources
Non-renewable energy comes from sources that will run out or will not be replenished in our lifetimes—or even in many, many lifetimes. Most non-renewable energy sources are fossil fuels: coal, petroleum, and natural gas. Carbon is the main element in fossil fuels.
Coal, crude oil, and natural gas are all considered fossil fuels because they were formed from the buried remains of plants and animals that lived millions of years ago.

36. Fossil Fuels

37. Argument for Nuclear Power as Renewable Energy
Most supporters of nuclear energy point out the low carbon emission aspect of nuclear energy as its major characteristic to be defined as renewable energy.
According to nuclear power opponents, if the goal to build a renewable energy infrastructure is to lower carbon emission then there is no reason for not including nuclear energy in that list.

38. Argument for Nuclear Power as Non- Renewable Energy
One of the biggest arguments against including nuclear energy in the list of renewable is the fact that uranium deposit on earth is finite, unlike solar and wind. To be counted as renewable, the energy source (fuel) should be sustainable for an indefinite period of time, according to the definition of renewable energy.
Another major argument proposed by the opponents of including nuclear energy as renewable energy is the harmful nuclear waste from nuclear power reactors. The nuclear waste is considered as a radioactive pollutant that goes against the notion of a renewable energy source. [1] Yucca Mountain is one of the examples used quite often to prove this point. Most of the opponents in the US also point at the fact that while most renewable energy source could render the US energy independent, uranium would still keep the country energy dependent as US would still have to import uranium.

39. Nuclear Power

40. Non-Renewable Resources
Over the past few decades, many oil companies have discovered oil below the seafloor near the coasts of many states. Some states, however, refuse to permit offshore oil drilling, fearing it might damage the environment. Discuss both sides of this issue. In your answer, be sure to:
state one way in which offshore oil drilling might have a long-term negative effect on the environment [1]
state one positive effect = a way in which offshore oil drilling could benefit society [1]

41. Coal production, 2002—by region.
                                                   
                                                  
Coal production, 2002—by region.
The top ten coal producing countries in 2002.

43. Oil production and consumption, 2002: regional distribution
                                                                                   

44. Proved oil reserves at end-2002: regional distribution.