© 2011 Pearson Education, Inc. Lecture Outlines Chapter 19 Environment: The Science behind the Stories 4th Edition Withgott/Brennan.

© 2011 Pearson Education, Inc.

Lecture Outlines

Chapter 19

Environment:The Science behind the Stories

4th Edition

Withgott/Brennan


This lecture will help you understand:

• Our energy sources

• Coal

• Natural gas

• Crude oil

• Alternative fossil fuels

• Environmental impacts of fossil fuels

• Political, social, and economic aspects

• Conserving energy and enhancing efficiency


Central Case: Oil or wilderness on Alaska’s North Slope?

• Alaska’s remote North Slope

- A pristine wilderness to some

- Untapped oil riches to others

• The Arctic National Wildlife Refuge is the focus of intense debate

- Should the “1002 Area”be opened to drilling?

• Opponents fear that drilling will sacrifice our national heritage

- For little gain


The three regions of Alaska’s North Slope

• The National Petroleum Reserve–Alaska (NPR–A)

- Supposed to remain untapped unless the nation faces an emergency

- Open ecologically sensitive areas for drilling in 2006

• Prudhoe Bay consists of state lands that are drilled for oil

- Which is transported via the trans-Alaska pipeline to the port of Valdez

• The Arctic National Wildlife Refuge (ANWR)

- Federal land set aside for wildlife and to preserve pristine ecosystems

- It has been called the “Serengeti of North America”


Alaska’s North Slope


We use a variety of energy sources

• We use energy in our homes, machinery, and vehicles and to provide comfort and conveniences

• Most of our energy comes from the sun - Solar, wind, hydroelectric, photosynthesis, biomass

• Fossil fuels = highly combustible substances from the remains of organisms from past geologic ages

• A great deal of energy emanates from Earth’s core - Geothermal power

• Immense amounts of energy reside in an atom’s bonds- This energy provides us with nuclear power


Fossil fuels: our dominant source of energy

• Global consumption is at its highest level ever• The high-energy content of fossil fuels makes them

efficient to burn, ship, and store • Electricity = a secondary form of energy that is easy to

transfer and apply to a variety of uses

Oil, coal, and natural gas have replaced biomass as our dominant sources of energy


The energy stream of the U.S. is complex

The U.S. energy stream is dominated by coal, oil, and natural gas


Resources are renewable or nonrenewable

• Renewable energy = supplies will not be depleted by our use - Sunlight, geothermal energy, and tidal energy

• Nonrenewable energy = we will use up Earth’s accessible store in decades to centuries - Oil, coal, natural gas, nuclear energy- To replenish the fossil fuels we have depleted so far

would take millions of years


Fossil fuels are created from fossils

• Fossil fuels were formed from organisms that lived 100–500 million years ago

• Aerobic decomposition = organic material is broken down and recycled in the presence of air

• Anaerobic decomposition = occurs with little or no air- Deep lakes, swamps- Produces fossil fuels


Fossil fuel reserves are unevenly distributed

• Some regions have substantial reserves

- Whereas others have very few

• How long a nation’s reserves will last depends on how much the nation extracts, uses, exports, and imports

• Nearly 67% of the world’s proven reserves of crude oil lie in the Middle East

- Russia holds the most natural gas

- The U.S. possesses more coal than any other country


Developed nations consume lots of energy

• People in developed regions consume far more energy than those in developing nations

- Using 100 times more energy per person

• Energy use in industrialized nations is evenly divided between transportation, industry, and other uses

• Developing nations use energy for subsistence activities

- Agriculture, food preparation, and home heating

- They use manual or animal energy, not fossil fuels


Regions vary greatly in energy consumption

The U.S. has 4.5% of the population but uses 20% of the world’s energy


It takes energy to make energy

• We don’t get energy for free

• To harness, extract, process, and deliver energy requires substantial inputs of energy

- Drilling for oil requires roads, wells, vehicles, storage tanks, pipes, housing, etc.

- All this requires energy

• Net energy = the difference between energy returned and energy invested

- Net energy = energy returned – energy invested


Energy returned on investment (EROI)

• Energy returned on investment (EROI) = energy returned/energy invested

- Higher ratios mean we receive more energy than we invest

- Fossil fuels have high EROI

• EROI ratios can change

- They decline when we extract the easiest deposits first

- We now must work harder to extract the remaining reserves

- U.S. oil EROI ratios have gone from 100:1 to 5:1


Coal

• The world’s most abundant fossil fuel

- Created 300–400 million years ago

• Coal = organic matter (woody plant material)

- Compressed under very high pressure in swamps to form dense, solid carbon structures

- Very little decomposition occurred


Coal is mined using two major methods

• Strip mining = for deposits near the surface

- Heavy machinery removes huge amounts of earth to expose the coal

• Subsurface mining = underground deposits are reached by digging tunnels to follow seams (layers) of coal

• Mountaintop removal = entire mountaintops are cut off

- Environmentally destructive

- Common in the Appalachian Mountains


Coal use has a long history

• Cultures have used coal for centuries

- Ancient China, Roman Empire, the Hopi nation

• Coal helped drive the Industrial Revolution

- It fueled furnaces to produce steam

• Coal is used to generate electricity

- Converting water to steam, which turns a turbine

• The U.S. and China are the primary producers and consumers of coal

- It provides half the U.S. electrical generating capacity


A typical coal-fired power plant


Coal varies in its qualities

• Coal varies in water and carbon content and its amount of potential energy

• Peat = organic material that is broken down anaerobically

- It is wet, near the surface, and not well compressed

• Additional pressure, heat, and time turn peat into coal

- Lignite = least compressed

- Sub-bituminous and bituminous

- Anthracite = most compressed and has the most energy


Coal contains impurities

• It has sulfur, mercury, arsenic, and other trace metals

• The sulfur content depends on whether coal was formed in salt water or freshwater

- Coal in the eastern U.S. is high in sulfur because it was formed in marine sediments

• Impurities are emitted when coal is burned

- Unless pollution control measures are used

- Ways to reduce pollution must be found

• The Earth holds enough coal to last a few hundred years


Natural gas burns more cleanly than coal• The fastest growing fossil fuel in use today

- 25% of global commercial energy consumption

• It is versatile and clean-burning

- Emits ½ as much CO2 as coal, ⅔ as much as oil

• It is used to generate electricity, heat homes, and cook

• Liquefied natural gas (LNG) = gas converted to liquid

- Can be shipped but there are risks of explosions

• Russia leads the world in production

- The U.S. leads the world in use

• World supplies are projected to last about 60 more years


Natural gas is formed in two ways

• Natural gas = methane (CH4) and other volatile hydrocarbons

• Biogenic gas = pure methane created at shallow depths by bacterial anaerobic decomposition of organic matter

- “Swamp gas”

• Thermogenic gas = methane and other gases arise from compression and heat deep underground

- Most of the gas that is extracted commercially

• Kerogen = organic matter that results when carbon bonds begin breaking

- Source material for natural gas and crude oil


Natural gas is often wasted

• Coalbed methane = from coal seams

- Leaks to the atmosphere during mining

- Contributes to climate change

• In remote oil-drilling areas, natural gas is flared (burned off)

- In Alaska, gas captured during oil drilling is being reinjected into the ground for future use

• Landfills produce biogenic natural gas

- Operators are capturing and selling it


Natural gas extraction becomes challenging

• The first gas fields simply required an opening

- The gas moved upward

• Most remaining fields require pumping by horsehead pumps

• Most accessible reserves have been depleted

- Fracturing pumps high-pressure salt water into rocks to crack them


Offshore drilling on the seafloor

• Requires technology to withstand wind, waves, and currents

- Produces 1/3 of our oil and 13% of our natural gas

• In 2008, Congress lifted a drilling moratorium along U.S. coasts

- In 2010, President Obama said vast areas would be opened for drilling

• British Petroleum’s Deepwater Horizon exploded

- Producing the worst oil spill in U.S. history


Heat and pressure form petroleum

• Oil is the world’s most used fuel

- Accounts for 35% of world’s energy use

- The U.S. uses the most, but China’s and India’s use is increasing

• Crude oil (petroleum) = a mixture of hundreds of different types of hydrocarbon molecules

- Formed 1.5–3 km (1–2 mi) underground

- Dead organic material was buried in marine sediments and transformed by time, heat, and pressure


Petroleum geologists find deposits

• Petroleum occurs in isolated deposits- Collecting in porous layers under impermeable layers

• Geologists drill cores and survey the ground and air to predict where fossil fuels may lie

• Of the 11.6–31.5 billion barrels of oil in the Arctic National Wildlife Refuge, only 4.3–11.8 billion barrels are “technologically recoverable” with current technology


Not all oil can be extracted

• Some oil is so hard to extract, it is not worth the cost

- As prices rise, economically recoverable amounts approach technically recoverable amounts

• Technology limits what can be extracted

- Economics determines how much will be extracted

• Proven recoverable reserve = the amount of oil (or any other fossil fuel) that is technically and economically feasible to remove under current conditions


We drill to extract oil

• Exploratory drilling = small, deep holes to determine whether extraction should be done

• Oil is under pressure and often rises to the surface

- Drilling reduces pressure, and oil becomes harder to extract

• Primary extraction = the initial drilling and pumping of available oil

• Secondary extraction = solvents, water, or steam is used to remove additional oil, but it is expensive

• We lack the technology to remove every bit of oil

- As prices rise, it becomes economical to reopen a well


Primary and secondary oil extraction


Oil refineries create petroleum products

• Refining = hydrocarbons are separated into different size classes and are chemically transformed- Creating specialized fuels for many uses


Petroleum products have many uses

Petroleum products are central to our lives


We may have depleted half our reserves

• We have used up 1.1 trillion barrels of oil

- Half our reserves

• Reserves-to-production ratio (R/P ratio) = the amount of total remaining reserves divided by the annual rate of production (extraction and processing)

• At current levels of production (30 billion barrels/year), we have about 40 years of oil left

• We will face a crisis not when we run out of oil, but when the rate of production begins to decline


We are facing an oil shortage

• Peak oil = rate of production peaks and then declines

- We experience an immediate oil shortage

• Production declines once reserves are depleted halfway

- This crisis will begin within the next several years

• Geologist M. King Hubbard predicted that oil production would peak around 1970

- His prediction was accurate, and U.S. production continues to fall

- Hubbard’s peak = the peak in U.S. production


U.S. oil production has already peaked


Global oil production is peaking

Discoveries of new oil fields peaked 30 years ago, and we are using more oil than we are discovering


Predicting an exact date for peak oil is hard

• We won’t recognize that we have passed peak production until several years have passed

- Companies and governments do not disclose their amount of oil supply

- Disagreement among geologists about reserves

- Some estimates predict greater than expected reserves

• Peak production will occur

- Our lives will be profoundly affected


The long emergency

• “The long emergency”: lacking cheap oil to transport goods, our economies collapse and become localized

- Large cities could not be supported without urban agriculture

- Fewer petroleum-based fertilizers and pesticides would mean increase in hunger

- Suburbs will become the new slums, a crime-ridden landscape littered with the hulls of rusted-out SUVs

• More optimistic observers argue that as supplies dwindle, conservation and alternative energies will kick in

- We will be saved from major disruptions


Canada is mining oil sands

• Oil sands (tar sands) = sand deposits with bitumen

- A form of petroleum rich in carbon, poor in hydrogen

- Degraded and chemically altered crude oil deposits

• Removed by strip mining

• Requires special extraction and refining processes

• Most is in Venezuela and Alberta


Oil shale is abundant in the U.S. west

• Oil shale = sedimentary rock filled with kerogen (organic matter)

- Can be burned like coal or baked in the presence of hydrogen (called pyrolysis) to extract liquid petroleum

• World’s supplies may equal 600 billion barrels

- 40% is in the U.S., mostly on federally owned land in Colorado, Wyoming, and Utah

• Low prices for crude oil have kept investors away

- But as oil prices increase, oil shale is attracting interest


Methane hydrate shows potential

• Methane hydrate (methane ice) = molecules of methane in a crystal lattice of ice molecules

• Occurs in arctic locations and under the seafloor

• Formed by bacterial decomposition in anaerobic environments or deep thermogenic formation

• Immense amounts could be present

- From 2 to 20 times the amount of natural gas

• We do not know how to extract it safely

- Extraction could cause landslides and tsunamis

- Releasing large amounts of methane – a greenhouse gas


Alternative fossil fuels have downsides

• Their net energy values are low because they are expensive to extract and process

- They have low energy returned on investment (EROI) ratios (about 2:1 compared to oil’s 5:1)

• Extraction devastates the landscape and pollutes waterways

- Oil sands and oils use strip mining and pollute water

- Alberta’s oil sands mined 30 years ago still have not recovered

• Combustion emits as much greenhouse gases and pollution as oil, coal, and gas


Fossil fuel emissions pollute

• Carbon dioxide is released into the air

- Driving changes in global climate

• Emissions cause severe health problems

- Cancer, irritation, poisoning

• Technology and legislation can reduce pollution

Carbon dioxide is the greatest impact of fossil fuel use


Clean coal technologies• Clean coal technologies = technologies, equipment,

and approaches to remove chemical contaminants while generating electricity from coal

• Scrubbers chemically convert or remove pollutants

- Removing sulfur dioxide or nitrogen oxides

• Coal that contains lots of water can be dried

• Gasification = coal is converted into cleaner synthesis gas (syngas)

- Which can be used to turn a gas or steam turbine

• These technologies have reduced pollution

- But clean coal is still a dirty way to generate power


Can we capture and store carbon?

• Even very clean coal still releases greenhouse gases• Carbon capture and carbon storage (sequestration)

- CCS captures CO2 emissions

- Then converts it to a liquid and stores it underground or in the ocean

• The $1.5 billion FutureGen project will design, construct, and operate a coal-burning power plant for electricity while capturing and storing carbon underground

• This technology is still too unproven to depend on- It prolongs our dependence on fossil fuels


Carbon capture and sequestration


Fossil fuels pollute water and air

• For 3 months, the Deepwater Horizon’s explosion spilled millions of barrels of oil into the Gulf of Mexico

• We have never had to deal with a spill so deep• The Gulf of Mexico suffered many impacts

- Countless animals (birds, shrimp, fish, etc.) died- Coastal marsh plants died, leading to erosion- Fisheries were devastated and fishermen lost jobs

• Oil from non-point sources enters waterways and aquifers• Alternative fossil fuels worsens the impacts

- They use and pollute massive amounts of water


Coal mining devastates natural systems

• Acid drainage = chemical runoff from strip mining enters waterways- Sulfuric acid leaches metals from rocks- U.S. regulations require companies to restore strip-

mined land, but complete restoration is impossible• Mountaintop removal removes tons of rock and soil

- Destroying immense amounts of habitat and creeks• Loosening of regulations in 2002 allowed companies to

legally dump debris into valleys and rivers- Regardless of the consequences


Mountaintop removal

Mountaintop removal has greater impacts than strip mining


The public pays the environmental costs

• Costs of alleviating environmental impacts are high- The public pays for them

• Costs are not internalized in the market price of fossil fuels- External costs are paid for in medical expenses,

environmental cleanup, and decreased quality of life• Gas prices and utility bills don’t cover production costs

- Government subsidies keep fossil fuel prices cheap- Fossil fuel industries get more than renewable ones

Part of our tax dollars pay for our fossil fuel energy use


Extraction modifies the environment

• More than drilling is involved in developing oil or gas- Roads, exploration- Infrastructure (housing, roads, pipes, waste piles)- Ponds collect toxic sludge- Groundwater is depleted and made saltier

• Substantial and wide-ranging damage to vegetation, air and water quality, and wildlife if ANWR were drilled- Others say damage would be minimal

• Directional drilling = wells are drilled in directions outward from a drilling pad, requiring fewer pads


Many nations depend on foreign energy

• We are vulnerable to supplies becoming unavailable or costly

- Seller nations control prices, causing panic and inflation

The U.S. imports 67% of its crude oil, meaning other nations control our energy supplies


The oil embargo of the 1970s caused panic

OPEC’s (Organization of Petroleum Exporting Countries) oil embargo caused panic and skyrocketing prices, spurring inflation


Oil supply and prices affect economies

• Hurricanes Katrina and Rita (2005) destroyed offshore platforms, causing oil and gas prices to spike

• The politically volatile Middle East has the majority of oil reserves

- Causing a constant concern for the U.S.

• The U.S. has a close relationship with Saudi Arabia

- Despite Saudi Arabia’s lack of democracy

- Because it owns 22% of the world’s oil reserves

• Iraq has 10% of the world’s oil

- Many believe this is why the U.S. invaded it in 2003


The U.S. has policies to reduce foreign oil

• The U.S. is developing its own reserves

• Many want drilling in ANWR

- Despite charges that drilling won’t help much

• It imports oil from several countries

• Companies are resuming extraction at closed sites

• The government funds research into renewable energy sources

• The Strategic Petroleum Reserve stockpiles oil in caverns under Louisiana as a buffer against shortages

- But this reserve equals just one month’s U.S. supply


The global trade in oil is lopsided


Residents may or may not benefit

• Oil companies provide jobs for millions

- Paying dividends to millions of investors

• Citizens in Alaska are paid dividends by the government

- Many support developing ANWR for jobs, health care, other services

• Money from multi-national companies may not reach residents

- Residents are not compensated for pollution, land degradation, and displacement

- Many still live in poverty, without water or electricity


How will we convert to renewable energy?

• Fossil fuel supplies are limited, and their use has consequences

• Nations have several options for future energy use:

- Continue relying on fossil fuels until they are no longer economically practical

- Immediately increase funding to develop alternative energy sources dramatically

- Steer a middle course and gradually reduce our reliance on fossil fuels

• We need to prolong fossil fuels through conservation


Consequences of our reliance on fossil fuels


Energy efficiency and conservation

• We need to minimize energy use from dwindling fossil fuel supplies

• Energy efficiency = obtaining a given amount of output while using less energy input

- Results from technological improvements

• Energy conservation = reducing energy use

- Results from behavioral choices

• We can extend our nonrenewable energy supplies

- Be less wasteful

- Reduce our environmental impact


Automobile efficiency affects conservation

• The OPEC embargo of 1973 caused increased conservation, but it didn’t last

- Without high prices and shortages, there was no incentive to conserve

- Government research into alternative energy decreased

- Speed limits increased

• Policy makers failed to raise the corporate average fuel efficiency (CAFE) standards

• Low U.S. gas prices do not account for external costs


CAFE standards• CAFE standards mandate higher fuel efficiency in cars

- Fuel efficiencies fell from 22 mpg (1984) to 19 (2004)

- They climbed to 21.1 in 2009

• In 2009 Congress mandated that cars must get 35 mpg by 2020

European and Japanese cars are twice as efficient as U.S. cars


The Cash for Clunkers program

• In 2009, the Obama administration tried to improve fuel efficiency, stimulate economic activity, and save jobs

• The “Cash for Clunkers” program paid Americans $3,500 to $4,500 to turn in old cars and buy new, efficient ones

• The $3 billion program subsidized the sale or lease of 678,000 vehicles averaging 24.9 mpg- Replacing vehicles averaging 15.8 mpg

• 824 million gallons of gasoline will be saved- Preventing 9 million tons of greenhouse gases- Creating social benefits worth $278 million


Drilling in ANWR will not fill U.S. oil demand

A little conservation and efficiency will save far more oil than ANWR has

ANWR holds oil equal to 1 year’s supply of oil at current rates of use


Personal choice and efficiency

• Energy conservation can be accomplished in two ways

• Individuals can make conscious choices to reduce energy consumption and increase conservation

- Drive less, turn off lights, buy efficient machines

• Energy-consuming devices can be made more efficient

- Cars and power plants lose ⅔ of energy as waste heat


We already have the technology we need

• The U.S. has become more efficient, but we can do better

- Cars: efficient engines, electric cars, hybrids, etc.

• Cogeneration = excess heat produced during electrical generation is used to heat buildings

- Or produce other types of power

- It can double the efficiency of a power plant


Efficiency in homes and consumer products

• Improvements can reduce energy to heat and cool homes

• Appliances have been reengineered to increase efficiency

• Federal standards reduce electricity used

• Consumers need to vote with their wallets by buying energy-efficient products

If all Americans bought energy-efficient appliances, U.S. energy expenditures would be reduced by $200 billion


We need conservation and renewable energy

• Conservation could save 6 million barrels of oil a day

• Conserving energy is better than finding a new reserve

- It decreases environmental impacts while extending our access to fossil fuels

• Conservation does not add to our supply of fuel

- We still need energy from somewhere

• The only sustainable guarantee of a long-term supply of energy is from renewable energy sources


Conclusion

• Fossil fuels have helped build our complex industrialized societies

• We are now approaching a turning point in history

- Fossil fuel production will begin to decline

• We can encourage conservation and alternative energy sources

- Or we can wait until fossil fuels are depleted

• Renewable energy sources are becoming feasible and economical

- We can envision giving up on our reliance on fossil fuels


QUESTION: Review

Which energy source is versatile and emits the least CO2?

a) Coalb) Natural gasc) Petroleumd) None of the above


QUESTION: Review

Which of the following describes when heavy machinery removes huge amounts of earth to expose coal?

a) Strip miningb) Subsurface miningc) Mountaintop removald) Illegal mining


QUESTION: Review

Which of the following does NOT describe natural gas that has been formed biogenically?

a) It was created in shallow water.b) It was created by bacteria.c) It is also called swamp gas.d) It was created deep underground.


QUESTION: Review

_____ contains the most oil in the world, while ______ consumes the most

a) Mexico, Japanb) Kuwait, Francec) Saudi Arabia, the United States.d) The United States, the United States.


QUESTION: Review

It is estimated that we have already depleted ___% of our global oil reserves.

a) 25%b) 50%c) 75%d) 100%


QUESTION: Review

Which statement about peak oil is NOT correct?

a) The United States has reached peak oil.b) Production declines once reserves are 75% depleted.c) Discoveries of new fields peaked 30 years ago.d) We are using more oil than we are discovering.


QUESTION: Review

What is a major problem of oil shale and tar sands?

a) Mining for them destroys the land.b) They release greenhouse gases.c) Mining and using them releases pollution.d) All of these are major problems of these sources of

energy.


QUESTION: Weighing the Issues

How is your life affected as oil becomes more expensive? What will you do?

a) I will start conserving gasoline by walking more or carpooling.

b) I need my car, so I will just have to earn more money.c) It won’t affect me, because I already minimize my

driving.d) It won’t affect me, because I have enough money to

afford gasoline.


QUESTION: Weighing the Issues

Should the government raise taxes on gasoline to reflect its true cost?

a) Yes; that would make people conserve gasoline.

b) Yes, but poor people would need subsidies to help them buy gasoline.

c) No; I don’t want to pay more for gasoline.

d) I don’t care; I have enough money to pay for expensive gasoline.


QUESTION: Interpreting Graphs and Data

According to this graph, the contribution of oil from ANWR over the next 50 years will be:

a) Extremely significant

b) Extremely insignificant

c) Very high

d) Worth drilling for


QUESTION: Interpreting Graphs and Data

According to this graph, what would you best conclude?

a) Fuel efficiency can increase in the United States.

b) U.S. efficiency goes only upward.

c) Fuel efficiency is not possible in the United States.

d) The United States does not need efficiency.

© 2011 Pearson Education, Inc. Lecture Outlines Chapter 19 Environment: The Science behind the Stories 4th Edition Withgott/Brennan.

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