Sbs 4e lecture ch19

© 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) Coal
b) Natural gas
c) Petroleum
d) None of the above

QUESTION: Review
Which of the following describes when heavy machinery
removes huge amounts of earth to expose coal?
a) Strip mining
b) Subsurface mining
c) Mountaintop removal
d) 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, Japan
b) Kuwait, France
c) 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.

Sbs 4e lecture ch19

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (12)

Similar to Sbs 4e lecture ch19

Similar to Sbs 4e lecture ch19 (20)

Recently uploaded

Recently uploaded (20)

Sbs 4e lecture ch19

Editor's Notes