9D – Water 9E – Atmosphere 9F – Nonrenewable Energy Environmental Science Unit 9 D-E-F Resource Management Part 2.

9D – Water9E – Atmosphere

9F – Nonrenewable Energy

Environmental ScienceUnit 9 D-E-F

Resource Management Part 2

• Air pollution• Air pressure• Air mass• Algal bloom• Aquifer• Atmosphere• Conduction• Convection• Cultural

eutrophication• Dam• Emissions• Energy• Fossil fuels• Fresh water

• Front• Greenhouse effect• Groundwater• Impermeable• Meltdown• Non point source

pollution• Nonrenewable energy• Nuclear energy• Nuclear fission• Nuclear waste• Oil sand• Oil shale• Ozone layer• Permeable

• Petroleum• Point source pollution• Primary pollution• Radiation• Recharge zone• Relative humidity• Renewable energy• Reservoir• Runoff• Secondary pollution• Surface water• Watershed• Water table• Xeriscaping

Unit 9D-E-F Vocabulary Terms (42)

• Explain how & why fresh water can be both a renewable yet limited resource.• Compare/contrast surface water & groundwater• Describe the structure of a watershed & suggest methods to manage it• Indicate the accessibility of ground water & surface water, & discuss the consequences of overuse• Outline solutions to freshwater depletion for agricultural, industrial & individual use• List & explain 2 terms used to describe sources of water pollution• List 3 types of water pollution & describe their effects on the environment• Describe how saltwater intrusion & ground water pollution are serious threats to Florida’s aquifier

Unit 9D Chp. 14 – Water - Objectives

•Choose your own group (2-4 people).•Choose an objective from the previous slide.•Prepare a 1-2 minute presentation on that subject.•You must have presentation visual that represents the objective you are conveying. This may be a poster, power point, model, song, or edible material or anything else you might creatively come up with.•Your group will present this information to the class for a grade based on: accuracy of information, presentation skills, and overall appearance of the visual. •Have fun with this. Due: Thursday March 26.

Chp. 14 Group Presentation Project

• Central Case – Looking for Water….in the Desert Pg. 419

•Read this case study and propose/analyze a solution

1. What is the problem????2. What is your proposed solution?3. Now, analyze your solution: 3 Pros, 3 Cons, 3

Short-term consequences, 3 Long-term consequences

4. Finally, form a conclusion about your proposed solution: Was it a good or bad solution and why?

Chp. 14 Water Resources

•Where is all of our water????????•Renewable resource – water cycle•Limited resource – 97.5% salt water, 2.5% fresh water (mostly ice); 0.5% is both fresh & liquid & available•People & water – unequally distributed•Seasonal availability – most parts of the world experience rainy & dry seasons

14.1 Earth: The Water Planet

•Surface water – water found on the surface, 1% of all fresh water; runoff – water that flows over land but has not been absorbed•River system – network of connected streams and rivers that flow downhill (gravity) in shallow grooves in the earth•Watersheds – all the land area that supplies water to a particular river system; St. Johns; the Mississippi River Watershed is the 3rd largest watershed in the world

Surface Water

•Water found below Earth’s surface•Makes up 1/5 of Earth’s freshwater supply•Aquifer – sponge-like formations of rock, sand, or gravel that hold water in the permeable layer•Permeable – layers of soil or rock that contain spaces or pores through which water can pass• Impermeable – layers with few or no pores, traps water which cannot move any deeper•Water table – boundary between the upper layer or zone of aeration and the lower layer or zone of saturation

Groundwater

•Any area where surface water soaks into the ground and reaches an aquifer below•A water table’s depth is affected by the shape of the land and by the amount of water available. As rock layers rise & dip, so does the water table; heavy precipitation/snowmelt causes it to rise, droughts to fall.•Well – hole dug into an aquifer to reach groundwater; usually dug into the zone of saturation.

Recharge Zone

1. Explain the conclusion that liquid fresh water on Earth is a limited resource.

2. What is a watershed? Why is it more effective to manage an entire watershed as compared to a single water source?

3. Why might you have to dig a well deeper if it is overused?

4. Most civilizations began near a source of fresh water. Over time, however, technology has enabled us to move fresh water great distances. In what ways do you think this kind of technology has contributed to the water shortages many people face today?

• In addition to the above 4 questions, do 14.1 packet.

14.1 Review

•Globally, 70% agriculture, 22% industry, 8% personal.•How can we change the way we use water?????•Agriculture – used for crops & livestock; 1,500 liters/1 kg wheat, 15,000 liters/1 kg beef• Industrial – used to make & transport products, cool off machinery in energy production, & used in refining process to make gasoline•Personal use – av. person in the US drinks 2-5 liters of water, bathing, cooking, laundry, flushing the toilet, watering yards, leaky pipes

14.2 Use of Fresh Water

•For homework, figure out your family’s daily use of water (personal use).•Poll your family on how long they take with showers, brushing teeth, hand washing,… as well as how many times/day they flush the toilet, run the dishwasher, do laundry, etc.•Finally determine how much water you use in watering your lawn, washing your car, or any other outdoor use. •Complete the form, computing your family’s daily use of water. Now list 3 ways you can conserve your use of water.

Home Water Survey

• Because of overuse, surface water resources are being depleted. • Water diversion – process of moving water from its source to places where humans use it (homes, fields)• Dams – any obstruction placed in a river or stream to block its flow; create artificial reservoirs• Benefits of dams: clean power generation, crop irrigation, flood control, shipping, recreation• Costs of dams: habitat alteration, fisheries decline, population displacement, sediment capture, loss of fertile farmland, risk of failure, lost recreation• Surface water depletion: drought and overuse have significantly reduced surface water resources; Colorado River, China’s Yellow River, Aral Sea

Using Surface Water

•Groundwater is being used, primarily for irrigation, faster than it can be replenished• Therefore, most groundwater use is unsustainable• 26% of fresh water used in US is from groundwater, 68% of which is for irrigation• Irrigated land has doubled since 1960, most of which is inefficient (runoff, evaporation)•Over-irrigation leads to waterlogging & salinization (buildup of salts in the surface layers of soil, eventually making the soil unusable)•Groundwater mining – withdrawing groundwater faster than it can be replaced

Using Groundwater

•Page 431 in your textbook•Read the information, use the graph, and complete questions 1-4.

Real Data – Lake Powell

•As groundwater is depleted, especially near the coasts, salt water moves into the aquifer (FL)•Desalination – removing salt from seawater• 7500 desalination plants worldwide (Tampa has one)• 2 methods: heat, filtration/reverse osmosis

•Reduce demand – conservation practices implemented• Agriculture – adopt efficient irrigation methods (drip) & select climate-appropriate crops• Industrial – water-saving steps, recycle wastewater• Personal – water at night, xeriscaping, low-flow toilets & shower heads, fix leaky pipes, etc.

Solutions to Freshwater Depletion

1. What are the 3 main categories of water use? Give an example of each.

2. Explain how water diversions and dams affect surface water depletion.

3. How does agriculture contribute to groundwater depletion?

4. For each of the following actions, indicate if the approach increases the supple of water or decreases the demand for water: (a) xeriscaping, (b) desalination, (c) fixing leaky pipes, (d) using drip irrigation.

• In addition, do 14.2 review packet.

14.2 Review

•How does water pollution affect humans and ecosystems?• Types of Water Pollution:1. Point-source pollution – comes from

distinct locations (ex. Factory, sewer pipe,…)

2. Nonpoint-source pollution – comes from many places spread over a large area (ex. Runoff, storm sewers, oil-covered streets,…)

•Point and nonpoint water pollution comes in many forms and can have diverse effects.

14.3 Water Pollution

• Eutrophication – buildup of nutrients in a body of water, aquatic plants & algae increase their growth rate, decomposition then increases as the autotrophs die, and dissolved O2 decreases•Cultural eutrophication – nutrient pollution by humans that speeds up the natural process, usually phosphorus (fertilizers, detergents)•Algal blooms – sudden explosions of algal growth due to excess nutrients, can cover the surface and block sunlight to other plants, decomposition increases, oxygen levels drop

Nutrient Pollution

• Example of nonpoint-source pollution resulting in cultural eutrophication

Lake Apopka

Revival of eelgrass beds

• Toxic chemicals can be organic or inorganic•Petroleum products (plastics) contain Bisphenol-A (organic) and heavy metals (inorganic)• Toxic chemicals released during industrial and manufacturing processes can make their way into fresh water via point and nonpoint sources•Results: poison aquatic animals & plants, human health problems (cancer)•Regulating industrial, manufacturing & agricultural processes to control the amount of toxic chemicals they use & release can help, but is hard to control nonpoint-source pollution

Toxic Chemical Pollution

•Sediments transported by rivers & runoff can harm aquatic ecosystems•Aquatic environments change with increase in sediments: photosynthesis decreases as water clouds up, food webs collapse, water quality degrades•Sediment pollution is a result of erosion, so decreasing erosion helps•Mining, clear-cutting, clearing land for houses, and careless farming practices all expose soil to wind and water erosion•Mississippi and China’s Yellow River (right)

Sediment Pollution

• The warmer the water, the less O2 it can hold•When human activities raise water temperature, some aquatic organisms may not survive due to increased water temperature or decreased O2 •Water is used for cooling industrial processes and power plants. It absorbs a lot of heat, resulting in thermal pollution•Removal of trees & plants that shade bodies of water can also cause thermal pollution

Thermal Pollution

•Pathogens (disease causing organisms) make their way into our air, soil, & water.• Exposure to animal or human waste contaminates our drinking water.•Biological pollution causes more human health problems than any other type of water pollution•Need to treat water & waste with chemicals or other substances that ill the pathogens•Over 3.4 million people die worldwide each year because of diseases carried in water (2/3 in South Asia and sub-Saharan Africa)

Biological Pollution

• It can take decades to clean up, so every effort should be made to prevent it from occurring.•Sources: many pollutants enter from the surface, human activities, multiple sources•Cleaning up: chemicals break down more slowly in aquifers than they do in surface water due to less dissolved O2, microbes, minerals & organic matter; groundwater moves slowly and takes a long time to recharge• Easier to prevent than clean up; EPA is working on a nationwide program to locate leaky gasoline tanks

Groundwater Pollution

•Oceans are polluted with oil, toxic chemicals & nutrients that run off from land.•Oil pollution: major oil spills make headlines, but most oil comes from many widely spread small sources (nonpoint); largest single source is naturally occurring deposits/oil seepage•Mercury pollution: toxic heavy metal that collects in tissues of animals; biomagnification•Nutrient pollution: nitrogen (not phosphorus) does most of the damage; algal bloom, red tide, toxins, hurts the economy with closed beaches and stopped fishing

Ocean Water Pollution

• Through Gov’t regulations & water treatment• The Clean Water Act (1977) – made it illegal to release pollution from a point source without a permit, set standards for pollution levels, & funded construction of sewage treatment plants•Great Lakes is a success story, decreasing nutrient & toxic-chemical pollution, bird populations are rebounding, & Lake Erie is now home to the world’s largest walleye fishery

Controlling Water Pollution

• Filtration, Coagulation, Settling, 2nd Filtration, Chlorination, Aeration, Additional treatment.• EPA sets the standards•Wastewater: water from showers, sinks, dish-washers, washing machines, toilets•Sewers carry wastewater from homes & businesses to centralized treatment locations• Effluent (treated water) is piped into rivers, reservoirs, or the ocean•Reclaimed water might not be treated to drinking water standards, so is used for irrigation or to cool power plants•Septic systems used in rural areas

Water Treatment

1.What is the difference between point & nonpoint sources of water pollution? Give an example of each.

2.Why is groundwater pollution so hard to clean up?

3.Explain how using nitrogen-rich fertilizers can affect algal blooms in the oceans.

4.Describe (not list) the steps involved in a typical public drinking water treatment process.

• In addition, do 14.3 review packet.• In addition, do the chap. 14 assessment pgs.447-9

14.3 Review

• List/describe the main properties of the atmosphere & explain how each relates to the other systems & cycles on the Earth.•Describe the layers of the atmosphere & their influences on the biosphere & weather.• Explain the importance of the ozone layer as it relates to Earth’s ability to sustain life.• List 2 examples of air pollution formed by natural processes & 2 examples caused by human activities.• Identify the main components of the Clean Air Act & explain how its provisions have set standards for air quality.

Unit 9E Atmosphere Chap. 15 Objectives

•How can we ensure everyone has clean air to breathe?•Read the Central Case Study (pg. 451 in textbook)•Work in pairs with the Decision Making Analysis format:• Identify the problem•Propose a solution• Then analyze your proposed solution: 3 Pros, 3 Cons, 3 Short-term consequences, 3 Long-term consequences.• Finally, draw a conclusion about your proposed solution, explaining why or why not your solution was a good one.

Chp. 15 Central Case Study: Air in London

•Atmosphere – thin layer of gases that surround Earth•We live at the bottom of the atmosphere, which provides us with oxygen, protects us from the most harmful rays in sunlight, and transports & recycles water.• It also burns up incoming meteors and helps control climate.

15.1 Earth’s Atmosphere

•Nitrogen (N2) – 78%• Nitrogen-fixing bacteria

•Oxygen (O2) – 21%• Living things need it, combustion

•Water vapor (H2O)•Other: Argon, CO2, Neon, Helium, Methane, Krypton, Hydrogen

Composition of the Atmosphere

• The ratio of water vapor the air contains to the maximum amount it could have at that temperature. •When humidity is high, sweat does not evaporate easily and the body cannot cool itself•Condensation – warm air holds more water vapor than cool air, condensation as it cools, dew & frost.•Cloud formation – water vapor needs a surface to condense on, clouds form on tiny particles in the air (salt, dust, smoke)

Relative Humidity

• The force exerted by air (particles) on the area below it. • Barometer – instrument that measures air pressure•Mercury barometers use a column of mercury pushed upward in a tube by air, expressed as inches• Aneroid barometers use a metal chamber whose walls bend inward (high) or outward (low) moving a dial, expressed as millibars• In general, the lower the altitude, the higher the air pressure; the air at the bottom of the column is bearing the weight of all the air above it

Air Pressure

1. Troposphere – lowest layer; blankets the Earth’s surface & contains the O2 we need, contains most of the clouds & weather, temperature decreases with height

2. Stratosphere – extends 11-50 km above sea level; gases don’t mix much, so substances stay there a long time; temperature rises with height; ozone (O3) concentrates in a portion of this layer filtering out UV light

3. Mesosphere – extends 50-80 km, tempera-tures decrease with height, low air pressure

4. Thermosphere – 80 km into space, air is very thin, temperature is high

Layers of the Atmosphere

•Weather – atmospheric conditions over short time periods in relatively small areas• Ex. – weather on summer days can be hot, dry, and sunny

•Climate – pattern of atmospheric conditions in large geographic regions over long periods• Ex. – London has a moist, temperate climate

• Energy from the sun heats the atmosphere, driving air movement in the troposphere•Heat transfers in the troposphere 3 ways: radiation, conduction, convection

Troposphere and Weather

1. Radiation – transfer of energy through space; no direct contact between heat source & object being heated, dark objects absorb more, light objects reflect

2. Conduction – transfer of energy/heat directly between 2 objects that are in contact with one another; occurs when molecules collide, only occurs between Earth’s surface & molecules directly in contact with it

3. Convection – transfer of heat by the movement of currents within a fluid; important method of heat transfer in the troposphere

Heat Transfer in the Troposphere

• The process of convection is related to density•Density – mass of a substance in a given volume•As air near the surface of the Earth gets heated, it becomes less dense; cool air sinks and warm air rises above it.•As cooler air sinks to the ground level, it picks up heat & begins to rise.•Sinking cool air & rising warm air form convection currents, which cause winds and move heat through the troposphere.

Convection Currents

•Air mass – a large body of air with similar temperature, pressure & humidity• Front – boundary between air masses that differ in temperature and moisture•Warm front – boundary along which a mass of warmer, moister air pushes against a mass of colder, drier air; warm, moist air rises then cools, water vapor condenses, forms clouds, rain•Cold front – boundary along which a colder, drier air mass pushes against a warmer, moister air mass; cold air tends to wedge beneath warmer air which then rises & forms clouds and sudden weather changes like thunderstorms

Air Masses and Fronts

•Obtain 2 100 ml. beakers; fill one halfway with cold water, fill the other halfway with hot water; squirt food coloring into the hot water until the water is a dark color; use a dropper to remove colored hot water, wipe dropper off with a paper towel; insert dropper into the cold water halfway and squeeze to release hot water•Observe and answer the 3 questions on pg. 459:

1. How did the hot water move in the beaker?2. Why did the hot water move the way it did?3. How is the movement of the hot water similar

to the movement of air in the troposphere?

Quick Lab Demo, page 459

1. Think of a swimming pool with a shallow end & a deep end. The pressure of water on the floor at the shallow end is less than the pressure of water on the floor at the deep end. How is this similar to the way air pressure differs at different altitudes?

2. Why is the temperature in the upper stratosphere higher than the temperature in the lower stratosphere?

3. How is a warm front different from a cold front?4. Winds occur because of convection currents in the

troposphere. How do you think winds affect air pollution?

• In addition, complete the 15.1 review packet.

15.1 Review

• Emissions – substances released into the atmosphere; particulate matter, gases•What are the sources of air pollution?•Natural processes – wind erosion blows dust, volcanic eruptions release ash & gases, fires produce smoke, soot & gases•Human sources – point & nonpoint sources; farming & grazing practices cause erosion; power plants & factories release emissions; combustion of fossil fuels from millions of cars & trucks

15.2 Pollution of the Atmosphere

•Primary – pollutants released directly into the troposphere; include soot, carbon monoxide, VOCs, dust, pollen, lead; may cause damage themselves or they may react with other products•Secondary – harmful products produced when primary air pollutants react chemically with other substances; include ozone, sulfuric acid

Primary & Secondary Air Pollutants

•Can damage the respiratory system, interfere with the body’s uptake of O2, & cause cancer.•Respiratory System Problems: irritate people’s air passages & lungs; asthma, bronchitis, emphysema.•Carbon Monoxide: hemoglobin is a molecule in red blood cells that combines chemically with O2; carbon monoxide will bind to hemoglobin, replacing the O2; headaches, tiredness, nausea, heart damage, fatal.•Cancer: soot if inhaled frequently, benzene from car exhaust.

How Air Pollutants Affect Your Health

•Smog – unhealthy mixture of air pollutants that may form over cities & nearby areas• Industrial smog is produced when soot combines with sulfur compounds & water droplets in air•Photochemical smog is a thick, brownish haze that forms when sunlight acts on certain air pollutants (nitrogen oxides, hydrocarbons, tropospheric ozone)• Temperature inversions may trap smog close to the surface of Earth, preventing the pollutants from dispersing.

Smog & Temperature Inversions

•Air temperature decreases as altitude increases.•Since warm air rises, pollutants in the air are carried away from the surface and higher into the troposphere, with some vertical mixing with the cool air• Thermal inversion occurs when a layer of cooler air is located above a layer of warmer air. This prevents the warm air with pollutants from rising, trapping them and any smog near the surface.

Temperature Inversions

•Results when products of combustion combine with water, oxygen, & other substances in the atmosphere, forming acids.• These acids settle to the surface of Earth as particles, or dissolve in fog or precipitation.• pH scale measures acidic & alkaline solutions; 0-14, 7 is neutral, the lower the pH the higher the acidity.•Sources of acid deposition: sulfur dioxide, nitrogen oxide, burning of fossil fuels, electric power plants• Effects: harm ecosystems & structures, kill trees, plants, fishes

Acid Deposition

1. Sulfuric acid & sulfur dioxide are both air pollutants. Use Figure 12, pg. 463 to determine which is a primary pollutant & which is a secondary pollutant. What is the relationship between these 2 types of pollutants?

2. When people work with volatile organic compounds, why should they wear special masks that cover their noses & mouths?

3. Why does a temperature inversion trap smog & prevent it from dispersing?

4. The rain that falls in an area has a pH of 5.8. Is this acid precipitation? Explain your answer.

• In addition, do 15.2 review packet.

15.2 Review

• The Clean Air Act (1963, 1970, 1990)•Goal is to protect &improve the quality of air in order to safeguard human health & the environment.• The Act limits emissions of pollutants by motor vehicles & industries• It sets standards for air quality, limiting the concentration of some specific pollutants (carbon monoxide, particulates)• It lets people sue industries that break the rules• It sets aside funds for research into pollution control.

15.3 Controlling Air Pollution

• Page 471 in textbook• Read the paragraph and answer the 6 questions:1. What do the green bars represent?2. What do the purple bars represent?3. What trend does the graph show?4. Of the pollutants shown on the graph, which has

changed by the greatest percentage?5. Why is the bar for lead shown separately from

the bars for the other pollutants? (hint: look at the axis labels)

6. Do you think that the general trend shown in this graph is also true for the air in London between 1952 & now? Explain your answer.

Real Data Effects of the Clean Air Act

• Since the Clean Air Act, the release of the worst air pollutants has gone down by 57% even though there are more people & we use more energy.• Cars & trucks now cause less pollution due to catalytic converters (changes harmful emissions into less harmful substances)• Gasoline once contained lead, which was part of the emissions. Today, gasoline contains almost no lead.• Industries & power plants are required to reduce pollutants; scrubbers remove or chemically change pollutants before they are emitted.

Reduction in Air Pollutants

•Ozone is a pollutant in smog in the troposphere•Ozone is highly beneficial in the lower stratosphere, absorbing UV radiation•By 1985, ozone over Antarctica was 40-60% lower than 10 years before. In 1974, 2 scientists predicted ozone depletion, identifying the cause as chlorofluorocarbons (CFCs). •CFCs are found in refrigerators, a/c, aerosol spray cans. CFCs were rising into the stratosphere and releasing chlorine atoms that react with ozone. • 1987 Montreal Protocol called for major cuts in CFC manufacture, & the ozone is recovering!!!

Ozone: Success Story

1. Overall, what has been the effect of the Clean Air Act? Give one reason why this has happened.

2. As time passes, what will happen to the amount of ozone in the ozone layer in the stratosphere? Give a reason for your prediction.

•Also, complete the 15.3 review packet.

15.3 Review

•Describe our need for a constant supply of energy for industry, commerce, transportation & personal use.• Explain the formation of fossil fuels and identify the 3 forms we use as fuel.• Evaluate the consequences of using fossil fuels and suggest conservation methods.•Describe how a nuclear power is harnessed to generate electricity and the pros & cons of its use.

Unit 9F – Chp. 17 Objectives

•Read page 515 Central Case.• Identify the problem.•Propose a solution to the problem.•Now, analyze your proposed solution: 3 Pros, 3 Cons, 3 Short-term consequences, 3 Long-term consequences.•After completing your analysis, form a conclusion about your solution (was it a good solution or not, and why?)

Chp. 17 Central Case: Oil or Wilderness on Alaska’s North Slope?

• Energy is the ability to do work or cause a change; classified as either kinetic or potential•Kinetic: energy that an object has due to it motion; whizzing baseball, crashing waves•Potential: energy that an object has because of its position or shape, energy that is stored; stretched rubberband, skier at top of hill

17.1 Energy: An OverviewWhat is energy & how is it used?

•Mechanical – energy associated with the motion & position of an object• Electrical – energy associated with electric charges• Thermal – kinetic energy of all the atoms & molecules in an object; faster they move, the warmer they become• Electromagnetic – energy traveling through space in the form of waves; visible light, radio, UV• Chemical – potential energy stored in bonds that hold atoms together in molecules; bonds break & release energy• Nuclear – energy involving forces within atoms; nucleus holds a lot of potential energy

Forms of Energy

• Energy can be converted or changed from one form to another•Combustion – the process in which a fuel burns because it combines rapidly with oxygen; chemical energy stored in the fuel is converted to thermal and electromagnetic energy•Chemical equation for the combustion of fossil fuels (natural gas is composed mostly of methane/CH4) is shown below:

CH4 + 2O2 CO2 + 2H2O*principal products of combustion of

methane are carbon dioxide and water vapor, both greenhouse gases

Energy Conversion

•Renewable energy – nearly always available somewhere on Earth’s surface, or they are replaced in a relatively short time; sun, wind, moving water, wood, heat from the mantle•Nonrenewable energy – cannot be replaced, once they are used up they are gone forever; fossil fuels, nuclear energy

Sources of Energy

• Fossil fuels form from the remains of organisms that lived millions of years ago.• Fossil fuels are composed mostly of hydrocarbons, and formed in an environment with little or no oxygen (deep lakes, swamps, shallow seas)• Temperature, pressure, and chemical composition of the starting material determine which fossil fuels are produced; oil comes from microscopic organisms, coal from plant remains compressed under very high pressure

17.2 Fossil Fuels

• Used to generate electricity, obtained by mining• Is the world’s most abundant fossil fuel, and its use goes back to ancient times•¼ of the world’s coal is located in the U.S.• Today, China & the U.S. are the main producers• Coal-fired steam engines drove the Industrial Revolution, powering factories, trains, & ships• Today, coal generates ½ the electricity used by Americans• Strip mining, mountaintop removal and subsurface mining are the methods used to remove coal from the ground• Advantages: abundant, less expensive, minimal processing, easily transported (no pipelines)

Coal

•Obtained by drilling, major source of energy• Found in the Middle East, Russia, N.A. & S.A.•Petroleum is the source of fuel for most forms of transportation•Petrochemicals are derived from oil & used to make many products, especially plastics•Oil deposits are deep underground, usually within sandstone & limestone• Extracted using pressure to force oil to surface•Crude oil must be refined to be usable, separating the crude oil into diff. fuels

Oil

•Yields a large amount of energy and is less polluting than other fossil fuels•Consists of the gas methane mixed in with small amounts of other gases.•Colorless and odorless; less polluting than gas or coal, & emits less carbon dioxide/unit of energy•Pockets of natural gas are often located above oil deposits, both on land and offshore• In U.S., pipelines carry natural gas from its source to where it is used•Also goes into products like paints, plastics, dyes, and fertilizers

Natural Gas

•No one knows for sure how long our supplies of fossil fuels will last, but they are finite• The most accessible reserves have already been used up; remaining deposits are often difficult & expensive to extract•Oil is in the least supply (40 years), coal supplies will last the longest (130 years in U.S.)•New sources, but many drawbacks: • Oil Sands – moist sand & clay containing bitumen• Oil Shale – rock filled with hydrocarbons• Methane Hydrate – icelike methane solid on ocean floor

Supply of Fossil Fuels

1. Where did the energy in fossil fuels originally come from ? What type of energy is stored in fossil fuels?

2. What are 2 major methods of obtaining coal from the ground? Compare these 2 methods.

3. How are rocks that contain oil similar to a sponge?4. What is one advantage that natural gas has over

coal and oil?5. Why is the supply of fossil fuels dwindling?6. The cost of researching technology to extract

alternative fossil fuels, such as oil sands & oil shale, is high. Do you think this is a wise investment? Explain your answer.

• In addition, do 17.2 review.

17.2 Review

•Workers risk their lives to obtain the fuels.•Pollution from burning of Fossil Fuels, contributing to climate change & cause pollution• Greenhouse Gases – all fossil fuels contain carbon, & release CO2 when burned, warming the atmosphere• Air pollution – burning coal & oil releases sulfur dioxide & nitrogen oxides, contributing to smog and acid deposition• Water pollution – oil from nonpoint sources runs off & contaminates water in & on the ground, huge oil spills cause environmental damage, offshore drilling rig spills• Health effects – mercury released in the air from burning coal, motor vehicles release irritants

17.3 Consequences of Fossil Fuel Use

•Mining is one of our most dangerous occupations, risking injury, death, respiratory disease•Strip mining destroys large tracts of habitat and acid drainage•Mountaintop removal has an even greater impact, destroying habitat and clogging waterways•Oil & Gas extraction involves drilling, roads, housing, pipelines, etc., all of which can harm plants, animals and ecosystems.

Damage Caused by Extracting Fuels

•Since fossil fuels are unevenly distributed in the world, many nations need to depend on foreign sources•U.S. has extensive coal deposits, Middle East have far more crude oil reserves•Almost all of our modern technology & services depend in some way on fossil fuels• The U.S. imports 2/3rds of its crude oil, so seller nations control the price and supply•We have diversified our sources of petroleum, importing from Canada, Mexico, Venezuela & Nigeria, but we need to develop renewable energy sources such as solar & wind power!!!!

Dependence on Foreign Sources

• To save fossil fuels & limit the damage they cause, we need to conserve energy.• This means reducing our use of them!!!!!!!!!!!!!!!!• Transportation accounts for 2/3rds of oil use in the U.S., so we need to design & sell motor vehicles that use less gasoline • Increasing the tax on gasoline would cause people to conserve it• Individual people need to make choices that save energy: driving less, turn lights off when not in the room, turn down thermostats

Energy Conservation

•Nonpolluting, yet radioactive waste disposal and nuclear power accidents cause concern•Nuclear energy – energy that holds protons & neutrons together in the nucleus•Nuclear fission – splitting of an atoms nucleus into 2 smaller nuclei• To produce nuclear fission, nuclei of large, unstable atoms (uranium, plutonium) are bombarded with neutrons, breaking up the nucleus & releasing heat & radiation, causing a chain reaction that is controlled and used to generate electricity

17.4 Nuclear Power

Nuclear Reactor

•Benefits: generates electricity without polluting, small amounts of uranium can produce far more energy than the same amount of coal, under normal conditions nuclear power plants are safer for workers than coal-fired power plants•Costs: plants are very expensive to build and maintain, fear of nuclear accidents is real (Chernobyl 1985), disposal of the radioactive waste materials left over•Currently, used fuel rods are held at nuclear power plants temporarily. U.S. chose Yucca Mtn. in Nevada desert (far away from people, little rain or risk of earthquakes, deep water table)

Benefits & Costs of Nuclear Power

•Nuclear fusion – small nuclei of lightweight elements are forced together to form a heavier nucleus, releasing a neutron & huge amounts of energy•Nuclear fusion has advantages over fission, but the technology does not yet exist to use fusion to generate power•Nuclear fusion reactions generate the energy released by the sun

Nuclear Fusion: The Future?

1. What is a nuclear chain reaction?2. List the steps involved in using nuclear fission

to generate electricity. Begin with the role of the fuel rods.

3. Why is the disposal of nuclear waste a greater problem than the disposal of the trash that you and your family need to get rid of?

4. Compare and contrast nuclear fusion and nuclear fission. How are they similar? How are they different?

• In addition, do 17.4 review packet.

17.4 Review