earth’s natural resources unit 7 standards: nces 2.2.2, 2.4.1, 2.5.5 lesson 1
TRANSCRIPT
Earth’s Natural Resources
UNIT 7STANDARDS: NCES 2.2.2,
2.4.1, 2.5.5LESSON 1
Lesson Objectives
In this lesson, you will learn about: What materials are considered
resources Which Earth resources are renewable Which Earth resources are
nonrenewable Which Earth resources are reusable How the Earth resources are used
Why are Resources Important
Can you imagine a world without air? With no land? With no water?
Resources video
People couldn’t live without air to breathe, water to drink, and land to walk on. Those three things are some of our planet’s most important resources. Resources refer to all of the natural materials that help people live on our Earth.
What are Resources? Natural
Resources
The resources the Earth provides to us.
Air, Water, & Land Animals & Plants Minerals & Rocks Energy Sources
Oil, Shale, Gas, Wood Wind, Animal, Water
What is Renewable The first kind of resources is renewable
resources. That means they can be “made new
again”. They can be replaced. For instance, we eat plants and animals.
We make clothes from cotton plants, and we can use cowhide to make leather shoes. But we can grow more cotton plants and raise more animals for leather.
They are renewable resources..
Renewable Resources Definition
Anime video
Resources that are replaced through nature at a rate equal to or greater than the rate of being used.
Or a resource that is “inexhaustible”
Basic concept: sunlight and anything that is alive and can be grown.
Renewable Resources Sunlight
Living things
The sun provides an “inexhaustible” source of energy. The sun will burn out in around 5 Billion years.
Plants & animals reproduce and are renewable
Crops…planted & harvested Grow chickens, cows, fish The replacement of renewable
resources at the rate they are consumed is called sustainable rate.
Non-Renewable Resources The second kind of resource is
nonrenewable resources. These resources can only be used once
and then they are gone. Although the earth can make more of most
of them, that process takes thousands or millions of years in many cases.
Oil, coal, and natural gas are nonrenewable resources. Once we burn coal, it cannot be recovered or used again.
Nonrenewable Resources Definition
Summary video
A resource that CANNOT be grown or raised.
The resource is in a fixed or finite amount. It can be used up.
They are used FASTER than nature can replace them.
Fossil fuels, gems, ores
A Reusable Resource ? Some resources, such as water and
air, are used again and again. They are reusable. The water that we drink and use for
cooking and washing has fallen to the earth as rain many times in the past.
Other people and animals before have breathed the air we breathe today; and it will be used again in the future.
Reusable Resources Definitio
n
Resources that are nonrenewable, but can be used over and over again. They can be recycled.
Metals Aluminum, copper, gold,
silver Glass Finished paper
Section Review 7.1.1 1. How are springs related to the water
table? 2. List four common sources of
groundwater pollution. 3. Why are chemical contaminants so
dangerous to the groundwater? 4. What can you do to conserve and
protect the groundwater so it will be safe and abundant for future use?
Land Resources Protected
Land
Of all the land in the US, 42% is classified as public lands (forests, parks, wildlife refuges).
Of this 73% is in Alaska while 22% lies in the West. Only 5% remains for the rest of the country.
All of the public lands are federally administered, namely the National Parks System.
The US Government issues permits to log, hunt, fish, or harvest in these lands.
Soil as a Resource Soil is a nonrenewable resource. That is, it
cannot be replaced if it is washed away by the rain, because it takes the earth a long time to make new soil.
How is soil made? Remember…Over millions of years, rocks
are slowly broken down into tiny pieces of sand. Dead plants (such as tree leaves, old corn stalks, or grass) and dead animals decaying on the ground are part of the soil.
Soil Loss: A loss of a Resource First, if we put buildings or roads on a
nice piece of land, we can no longer plant that part of the soil or use it for anything else as long as the building or highway remains.
Second, if we dump chemicals or poisons on the land, we contaminate the soil and cannot use it.
Third, if we lose soil through erosion, we cannot recover it. In order to protect land as a resource, we need to control erosion.
Uses of Soil as a Resource Aggregate
s
Ores
Gravel, sand , and crushed stone that accumulates near the earth's surface.Used in construction.
An ore is a natural resource mined for profit. Most ores contain metals that are refined for human use.
Other Soil/Rock Resources Bricks
Clays
Placer
Salt
Made of clay; a sediment from erosion along with other minerals.
Also used in pottery, ceramics, and tiles
Gold, Silver, Platinum are deposited by erosion of parent rock.
Formed by the evaporation of an inland sea.
Minerals- A Non-Renewable An ore is a mineral or rock that is mined from
the ground. We mine iron ore to make steel. We use copper ore to make copper for pennies and other uses.
Once the minerals are mined, however, the earth does not make more of them. That is why we need to be careful when we use the ores we have.
Many communities recycle metal products: aluminum cans, pieces of steel and copper wire. Recycling lets us use nonrenewable resources over and over instead of losing them.
Using Land Resources Sometimes the extraction (mining) of
resources has a negative impact on the land.
Open-pit mines leave behind rock waste as well as a large hole in the earth.
The “slag” created by coal mining is hazardous to water.
Mining for gold in underdeveloped countries often includes the use of mercury. The miners are exposed to mercury poisoning.
Crazy as a mad hatter.
Section Review 7.1.2 1. Describe 2 resources found on
land. 2. Why is topsoil loss through
erosion a worldwide problem? 3. What is the difference between an
aggregate and an ore? 4. What options would humans have
if a land resource was depleted?
Air—A Reusable Resource What is air? It is a mixture of gases. If we
look at the air around us, we cannot see anything. The air is clear and colorless. But it does not mean that nothing is there. The molecules of the compounds that make up our air are moving very fast and are more spread out than in solids and liquids.
The air surrounding the earth is called the atmosphere. It is made up mainly of two gases, and there are tiny amounts of other gases present as well.
Composition of Air Nitrogen makes up 78%. Oxygen makes up 21 %.
Carbon dioxide makes up less than 1%.
We can see that there is more nitrogen than anything in the atmosphere.
People do not need nitrogen to breathe, but plants cannot grow without it.
Nitrogen Cycle Nitrogen moves from the
air to the soil, where it is taken up by the roots of the plants and used for food. After the plants have died, the nitrogen is slowly released and returned to the air again.
This cycle repeats itself all of the time. Nitrogen joins air when there is lightening during a storm. These nitrogen compounds are then carried to earth when it rains. Once in the soil, these nitrogen compounds are changed by bacteria into a form of nitrogen that plants use for growing.
Carbon dioxide – Oxygen People and animal
inhale oxygen and exhale carbon dioxide.
Carbon dioxide is left over in our bodies as a “waste product”.
On the other hand, plants need carbon dioxide to make their own food. They give off oxygen as a waste product.
During the last 200 years, factories have been built. Coal is burned as a fuel to provide much of the heat and energy these factories require.
When coal is burned smoke, water, and other gases are released. One of these is carbon dioxide. If we release too much carbon dioxide, we could upset the balance of the atmosphere.
Section Review 7.1.3 1. Why is air considered a resource? 2. How did oxygen originate on Earth? 3. Explain how the oxygen cycle and
carbon dioxide cycles are related. 4. Why is the nitrogen cycle important? 5. Describe how air can be polluted by
natural processes and human activities.
Water—A Reusable Resource Importanc
e of Water
71% of the Earth’s surface
Help regulate climate Provide habitats for
animals Shape the Earth’s
surface Dilute many pollutants
Important Properties of Water Liquid water
Heat Storage
Liquid water as a Solvent
Solid water expands
Required for life on Earth. Puts out fires.
Liquid water can store great amounts of heat energy. Coolants and sweat.
Water can dissolve a variety of compounds. Carries nutrients and part of cell life.
Solid water expands and will fracture rock.
Location of Freshwater Eastern US
Western US
Worldwide
Ample supply to replenish amount used.
May be contaminated by industry
Scarce amounts, cleaner water. Water tables dropping as more is used and less replenished.
No equal distribution, Africa in constant drought.
Uses of Freshwater Look at the graph Let’s discuss the
major uses of freshwater.
Why does manufacturing account for 4% but is the leading factor in pollution?
Projected Water Scarcity
Freshwater Management Dams
Transportation
Desalination
Manmade or natural obstructions across waterways that cause water to back up and be stored.
Rivers and channels allow for ships to carry goods and people. Inexpensive way to transport.
Removal of salt from water to make it potable (fit for consumption)
Managing Freshwater The US uses the EPA
(Environmental Protection Agency) as the chief enforcer of water use, access, and safety of water.
Other major agencies include: Department of Transportation Homeland Safety US Fish and Wildlife US Energy Agency
Section Review 7.1.4 1. Why is clean water important to life
on Earth? 2. How does the distribution of water
affect humans? 3. How does relocation of people
change the demand for freshwater? 4. What are possible solutions to the
growing water shortage? 5. Discuss the cost of operating a
desalination plant.