1. Earth Science 4.3 Water, Air, Land Resources

2. Key Concepts Why is fresh water a vital resource?
Why is the chemical composition of the atmosphere important?
What are Earth’s important land resources?

3. The Water Planet Water covers nearly 71% of Earth’s surface
Most of this water is salt water, not fresh water
While salt water oceans are important for our climate and are an important part of our ecosystem; fresh water is what we as humans need to live.
Every day we use fresh water for drinking, cooking, bathing and growing food
Less than 1% of the water on the planet is usable fresh water

4. Freshwater Pollution
Contamination of our freshwater supply is an important issue.
There are two types of water pollution
Point Source Pollution
Nonpoint Source Pollution

5. Point Source Pollution
Point source pollution is pollution that comes from a known and specific location

6. Nonpoint Source Pollution
Nonpoint source pollution does not have a specific point of origin.
Runoff, the water that flows over the land rather than seeping into the ground, often carries nonpoint source pollution
Runoff can carry waste oil from streets, sediment from construction sites, or pesticides from farm soils
Water filtering through piles of waste rock can carry sulfuric acid into rivers and streams killing fish
Pollutants from eating contaminated fish can damage our bodies major organs and systems, cause birth defects and cause certain types of cancers

7. Earth’s Blanket of Air
Earth’s atmosphere is a blanket of nitrogen, oxygen, water vapor and other gases
The chemical composition of the atmosphere helps maintain life on Earth
First and foremost, people and animals need oxygen to breath
The atmosphere is also part of other cycles

8. Earth’s Blanket of Air
The carbon cycle of Earth’s atmosphere makes vital nutrients available to many life forms
The atmosphere also makes life on land possible by shielding Earth from harmful solar radiation

9. Earth’s Blanket of Air
Earth’s ozone layer high in the atmosphere helps protect us from solar radiation
Ozone is a three-atom form of oxygen that protects Earth from 95% of the sun’s harmful ultraviolet radiation
Certain greenhouse gases in the atmosphere help maintain a warm temperature near earth’s surface

10. Pollution in the Air
Pollution can change the chemical composition of the atmosphere and disrupt it’s natural cycles and functions
Fossil-fuel combustion is the major source of air pollution. Most of this pollution comes from motor vehicles and coal or oil burning power plants

11. Pollution in the Air
Power plants release sulfur dioxide and nitrogen oxide. These pollutants combine with water vapor to create acid precipitation
The burning of fossil fuels also produces carbon dioxide, an important greenhouse gas.

12. Pollution in the Air
The amount of carbon dioxide in the atmosphere has increased dramatically in the past 100 years with the industrial revolution
This increase has altered the carbon cycle and contributed to global warming. Global warming could lead to huge changes in the Earth’s climate such as the melting of polar ice caps.

13. Pollution in the Air
Chlorofluorocarbons (CFCs) destroy ozone in the upper atmosphere. A significant loss of ozone has resulted in the increased risk of health problems related to too much UV radiation exposure such as skin cancer and cataracts.
Because of a growing hole in the Earth’s ozone layer, we now are unable to spend time outdoors without being conscious of the affects of sun-damage to our skin

14. Pollution in the Air Air pollution is a major public health problem
Long term health effects include asthma, bronchitis, emphysema, and lung cancer
The US EPA estimates 200,000 deaths each year are associated with the outdoor air pollution

15. Land Resources
Earth’s land provides soil and forests, as well as mineral and energy resources
Removing and using resources from earth’s crust can take a heavy environmental toll.

16. Land Resources
There are essentially 500,000 mines in the United States. While mines are essential to our economy and energy usage, mining tears up Earth’s surface and often destroys the landscape.
Mining also causes soil erosion, creates pollution through runoff, and contaminates surrounding water supplies as well as destroys entire ecosystems

17. Affects of Agriculture
Agriculture and farming have heavy affects on the land as well
While many dry areas are now being farmed thanks to irrigation, this heavy pumping and water use is depleting groundwater supplies in areas
Over time, irrigation causes salinization ( the buildup of salts) . Eventually the soil becomes useless for plant growth. With the loss of plant growth soil deteriorates and becomes a dust bowl.