Energy Sources and Consumption
Just a few hundred years ago, almost all energy used by people was derived from
local energy sources (agriculture, wind and water)
People relied on their own physical energy and the
energy of animals to do
These energy sources were limited by
, the amount of energy
contained within an energy source
Today, 60% of the commercial energy consumed worldwide is used by high
developed countries (HDCs)
People in HDCs rely o
n energy consuming machines to do work
The larger energy input is one reason the agriculture productivity of HDCs is
greater than that of developing countries
Additional energy demands may be met by increased
An increase in economic devel
opment is usually accompanied by a rise in per capita
In the U.S., industry (production of materials) accounts for 42% of energy
consumption, 33% is used to make buildings and/or homes comfortable, and 25% is
used primarily in transporta
Energy for China
In 2004, China became the world’s second largest importer of oil
China currently dominates international concerns over global climate
In 2009, China will likely pass the U.S. as the top CO
Energy is obtai
ned from a variety of sources, including
(coal, oil, and
natural gas), nuclear reactors, biomass, solar and other alternative energy sources
(water, wind, etc.)
Fossil fuels supply most of the energy required in North America
; formation does not keep pace with current
How fossil fuels are formed
was formed from the remains of ancient plants that lived millions of
was formed from the remains of ancient microscopic aquatic organisms
is composed primarily of
and was created in much the
same way as oil, except at higher temperatures
In the 18
century, coal replaced wood as the dominant fuel in the Western world
Coal powered the steam engine and supplied the energy for
Today it is used to produce electricity and steel
Coal consumption has surged in recent years in China and India
Lignite, subbituminous coal, bituminous coal, and anthracite are the four most
common grades of coal
is a so
ft, moist coal that produces little heat and is often used to power
electric power plants
coal has a relatively low heat value and sulfur content, and is
also used in coal
fired electrical power plants
(soft) coal produces substant
ially more heat that the lignite or
subbituminous, but also contains a higher sulfur content; it is used extensively
in electric power plants
(hard) coal is the highest grade of coal and produces the fewest
pollutants per unit of heat released (
due to low sulfur content); it has the
producing capacity of any grade of coal
Coal is the most abundant fossil fuel in the world, and is found primarily in
the Northern Hemisphere
World coal reserves could last more than 200 yea
rs at the present rate of
extracts the mineral and energy resources near Earth’s surface
by first removing soil, subsoil, and overlying rock strata
It is used to obtain 60% of the coal mined in the U.S
It is often ch
eaper, safer, and generally allows more complete removal
of coal from the ground
It does, however, have the potential to cause more serious
extracts the mineral and energy resources from deep
fety problems associated with coal
During the 20
century, more than 90,000 American coal miners died in
Miners have increased risk of cancer and
black lung disease
Environmental impacts of the mining process
Prior to 1977 (SMCRA
rface Mining Control and Reclamation Act),
abandoned surface coal mines were usually left as large open pits or trenches
and streams were polluted with sediment and
acid mine drainage
The SMCRA requires coal companies to restore areas that have been surfac
mined, requires permits and inspections of active coal mine operations, and
prohibits coal mining in sensitive areas
Mountaintop removal is one of the most land
destructive types of surface
mining; it uses a
to remove the mountain top to reach t
he coal below
Environmental impacts of burning coal
The Earth’s CO
equilibrium has been disrupted by the enormous amounts of
produced through fossil fuel consumption this past century
This, in turn, has lead to a rise in global temperature and various
environmental issues associated with higher temperatures
Melting of polar ice caps
Rising sea levels
Future flooding of coastal areas, increasing coastal erosion and
associated violent storms
Coal burning generally contributes more air pollutants (includi
does burning either oil or natural gas (i.e., mercury, sulfur oxides, nitrogen
Making coal a cleaner fuel
It is possible to reduce sulfur emissions associated with the combustion of
coal by installing
clean the power plant’s exhaust
Modern scrubbers remove 98% of the sulfur and 99% of the
particulate matter in smokestacks
Desulfurization systems are very expensive
Selling the sulfurs or metals removed from polluted emissions as a marketable
product is c
Clean Air Act Amendments of 1990
required the nation’s 111 dirtiest coal
burning power plants to cut sulfur dioxide emissions
This cut emissions by 3.8 million metric tons nationwide
The second phase of this amendment called fo
r 200 additional power
plants to make SO
cuts by 2000
This reduced the total annual emission by 10 million metric
A nationwide cap on SO
emissions was imposed after 2000
Clean coal technologies are new methods being developed for burning
that will not contaminate the atmosphere with sulfur oxides and will
significantly reduce nitrogen oxide contamination
coal gasification and liquefaction
two new clean coal technologies
These new technologies have litt
le impact on reducing CO
Oil and Natural Gas
Beginning in the 1940s, oil and natural gas became increasingly important as energy
sources due to easier transport and cleaner burning
In 2005, oil and natural gas supplied 63% of the energy used in
In 2004, oil and natural gas supplied 60.6% of the world’s energy
Petroleum (crude oil)
is separated into gases, gasoline, heating oil, diesel oil, and
asphalt during the refining process
Oil is used to produce
used in fertilizers,
plastics, paints, pesticides,
medicines, and synthetic fibers
Natural gas is separated into propane, butane, and ethane; it costs four times more to
transport through pipelines than crude oil
Liquefied petroleum gas
(propane and butane) is used as fuel for
Natural gas is used to produce both electricity and steam in a process called
Natural gas as a fuel for trucks, buses, and automobiles offers significant
environmental advantages over gasoline or diesel
Exploration for oil
and natural gas
Oil and natural gas deposits are usually discovered indirectly by the detection
; geological analysis to find structural traps is extremely
Many important oil and natural gas deposits are found in association w
Reserves of oil and natural gas
Distribution is uneven; a large share of total oil deposits are clustered
relatively close together (Persian Gulf region, Venezuela, Mexico, Alaska,
Almost half of the world’s proved recoverable reserves
of natural gas are
located in Russia and Iran
Many countries engage in offshore drilling for oil despite problems such as
storms at sea and the potential for major oil spills
How long will oil and natural gas supplies last?
Some experts think that global
oil production has already reached
(aka Hubberts Peak), others believe it will be reached around 2035
About 80% of current production comes from oil fields discovered before
1973, and most of these have started to decline in production
demand and supply
The U.S. currently imports more than half of its oil; this dependence has
potential international security implications as well as economic impacts
The imbalance between oil consumers and oil producers will probably worsen
in the future b
ecause the Persian Gulf region has much higher proven reserves
than other countries
Environmental impacts of oil and natural gas
Problems that result from burning fuels (combustion)
Every gallon of gas burned in a car releases an estimated 9kg of CO
the atmosphere; global warming results from increased CO
Increased acid deposition, photochemical smog, and increased
particulate matter result from combustion
Problems such as serious spills along transportation routes are involved in
Synfuels and Other Potential Fossil Fuel Resources
are fuels that are similar or identical to the chemical composition of oil or
natural gas (i.e.,
tar sands, oil shales, gas hydrates, liquefied coal, and coal gas
Synfuels are more
expensive to produce than fossil fuels
Environmental impacts of synfuels
Synfuels have many of the same undesirable effects as fossil fuels
Release of CO
and other pollutants into the atmosphere
They require large amounts of water during production; limi
usefulness in arid lands
Large areas of land would have to be surface mined to recover the fuel in tar
sands and oil shales
The U.S. Energy Strategy
A comprehensive national energy policy should consider the following elements
Increase energy efficienc
y and conservation
Secure future fossil fuel energy supplies
Develop Alternative Energy Sources
Meet the first three objectives without further damage to the environment
How politics influences the national energy policy
The Energy Policy Act of 2005 focus
es largely on supporting energy research
for fossil fuels
Instructor Notes for In
Class Activity 1
Examples of Fossil Fuels.
10 minutes prep; 15
25 minutes in class
Samples of fossi
l fuels (and charcoal, firewood, candles, etc). This can
include camping propane, vials of different sorts of crude, diesel and
gasoline (be sure to used approved containers!), pieces of coal (more than
one kind, ideally), different sorts of charcoal, pres
sed firewood and other
Alternatively, you may wish to bring images that can be accessed at
Have students inspect the different sorts of fossil and biomass fuels. Then
have them, in groups of 3
make notes about color, weight, fluidity.
Then have them research (using the text and internet resources) the
advantages and disadvantages of the different fuels for different
Some relevant attributes of fuels:
Vehicle fuel (cars, trucks, busses, ships, trains)
Industrial heating and manufacture
Have students think about and discuss why coal became the first major
Be sure student understand what charcoal is, how it is created. In
particular, be sure that they are aware that it is NOT a fossil fuel.
Define fossil fuel, and distinguish between coal, oil and natural gas.
Instructor Notes for In
Class Activity 2
Geography, Fossil Fuels and the Future
5 minutes prep; 15
20 minutes in class
Figures depicting coal, oil and natural gas resources by country
udents, working in groups of 3
4, look at which countries or
regions have access to ANY or SOME fossil fuels. Have them pay
particular attention to which less developed countries have little or no
domestic energy resources. Then have them consider these
report back to the class for a larger discussion:
Are domestic fossil fuel resources necessary for development?
What are the development options for a less developed country
that has few if any domestic fossil fuel resources?
Do all highly d
eveloped countries have domestic fossil fuel
resources? If not, where and how did they access the fuels used
Compare energy use in highly developed and devel
Instructor Notes for In
Class Activity 3
Phase I and Phase II Vapor Recovery
10 minutes prep; 15
30 minutes in class
Old nozzle from a gasoline station (or images, available at vendor
s of gasoline trucks unloading at a local gas station.
Better yet, get permission to tour a gas station while a truck is off
In many areas, Phase I (capturing vapors from emptied underground
tanks) and Phase
II (capturing vapors in emptied automobile gas tanks)
vapor recovery systems are required. Gasoline vapors can represent a
significant contribution to the creation of ground level ozone.
Most students are familiar with Phase II equipment, whether or not
are aware. As gasoline goes into an empty tank, vapors are forced out of
the tank. These vapors can be captured by a sheath around the nozzle,
and returned through a second hose (often integrated into the main hose),
and from there back into the under
Then, when the gasoline truck comes, as it empties, the vapors from the
underground tank are returned to the truck. When the truck goes back to
be filled, the vapors can be condensed into useable gasoline, or burned.
Assignments from studen
Inspect the nozzles and/or images.
Take notes about the system design.
Compare current designs with earlier designs
Estimate the amount of gasoline that is used in your area in a
day. For each gallon of gas pumped, at least one gallon of
be released to the atmosphere if it is not captured.
Discuss the environmental problems of using oil.
Instructor Notes for In
Class Activity 4
How much is left?
10 minutes prep; 30 minutes
Divide the class into three groups.
Let them pick out of a hat which group they will be researching. You
will have an OIL team, Natural Gas Team and a Coal Team. Their
assignment is to prepare an obituary for their fuel and present it to the
might want to write it up in Newspaper format.
You have been assigned a product either OIL, Natural Gas or Coal. The
earth has just run out of this material and you are to write an obituary for
this product. Be creative and in
formative. Some of the things you might
mention in your research for this obituary is the time spent on earth, the
value, who was helped or hurt by the existence of your product etc.
Define Fossil Fuel, and
distinguish among coal, oil and natural gas.
Discuss the advantages and disadvantages of coal, oil and natural gas.
Instructor Notes for In
Class Activity 5
Diary of the energy you use
10 minutes prep; 1 week out of class time
Discuss with students the amount of energy used for an average
household. Can we live without certain forms of energy produced from
coal, oil and natural gas? Have the students keep a diary of the energy
ey use from the time they get up to the time they go to bed. They may
need a small pocket notebook to keep with them so they can keep track of
the energy they use not only at home but in school, to and from school, at
their jobs etc.
Take a small notebook that is easily kept with you and every time you use
any form of energy by natural gas, coal, or oil, you will write it down with
the time use and estimate how much was used. Note: You might check
and see if your electricity is
fueled by gas, coal or oil. Or you could put
another line to monitor the amount of electricity used and do your
calculations later. After you spend a week collecting data on your use of
dependency on oil, natural gas and coal is it a reality in
Compare per capita energy consumption in highly developed and
Answers to Thinking About the Environment
End of Chapter Questions:
1. The Industrial Revolution
may have been concentrated in the Northern Hemisphere because
coal is located there. What is the relationship between coal and the Industrial Revolution?
Ans: Although coal was used as a fuel for centuries, not until the 18th century did it begin to
lace wood as the dominant fuel in the Western world. Since then, coal has had a significant
impact on human history. It was coal that powered the steam engine and supplied the energy for
the Industrial Revolution, which began in the mid
18th century. Today
utility companies use coal
to produce electricity, and heavy industries use coal for steel production. Coal consumption has
surged in recent years, particularly in the rapidly growing economies of China and India, both of
which have large coal reserves.
2. Few countries in Africa have significant amounts of coal, oil and natural gas resources. What
does this suggest about opportunities for financial development in those countries.
Ans: Africa, with the exception of a few countries, have few fossil fuel
resources. Their only
options for expanding energy use will be to purchase fossil fuels from other countries or develop
alterative resources. Either of these approaches requires substantial financial capital
resource generally lacking in developin
g countries. This will result in limited financial
development opportunities for many counties.
3. Does thinking of “oil addiction” literally, as depicted in Figure 11.20 provide a useful way to
get away from this addiction? Why or why not?
4. How does U.S. dependence on foreign oil affect our energy security?
Ans: This dependence of the U.S. on Middle Eastern oil has potential international security
implications as well as economic impacts. The imbalance between oil consumers an
producers will probably worsen in the future because the Persian Gulf region has much higher
proven reserves than other countries. At current rates of production, North America's oil reserves
will run out decades before those of the Persian Gulf nati
ons. Given this situation it is important
that the U.S. find ways to increase its energy security by reducing consumption or finding other
5. On the basis of what you have learned about coal, oil, and natural gas, which fossil fuel do you
the United States should exploit in the short term (during the next 20 years)? Explain your
Ans: Answers will vary.
6. Explain why the United States Department of Energy describes coal as a “true measure of the
energy strength of the United
States.” Is this also true of China? India? Why or why not?
Ans: Answers will vary.
7. In your estimation, which fossil fuel has the greatest potential for the 21st century? Why?
Ans: Answers will vary.
8. Which of the negative environmental impacts as
sociated with fossil fuels is most serious?
Ans: Answers will vary.
9. Which major consumer of oil is most vulnerable to disruption in the event of another energy
crisis: electric power generation, motor vehicles, heating and air conditioning, or in
Ans: Motor vehicles are most at risk for another energy crisis because they rely so heavily on
gasoline. Electric power companies use coal to produce electricity, and heavy industries use coal
for steel production. The United States has 25% o
f the world's coal supply in its massive
deposits. Natural gas efficiently fuels residential and commercial air
cooling systems and well as
10. What are the implications of “Peak Oil” on future global energy supplies?
Ans: The most optim
istic predictions are for Peak Oil at around 2035. After which point global
oil supplies will decrease and energy needs will have to be met by other sources.
Natural gas is more plentiful than oil. Experts estimate that readily recoverable reserves of
ral gas, if converted into a liquid fuel, would be equivalent to between 500 billion and 770
billion barrels of crude oil, enough to keep production rising for at least 10 years after
conventional supplies of petroleum have begun to decline. However, if th
e global use of natural
gas continues to increase as it has in recent years, then its life supply will be much shorter than
current projections predict. Analysts say the world must move quickly to develop alternative
energy sources because the global deman
d for energy will only continue to increase.
11. Do you think oil drilling should be permitted in the Arctic National Wildlife Refuge? Why or
Ans: Answers will vary.
12. Some environmental analysts think that the latest war in Iraq was related
in part to gaining
control over the supply of Iraqi oil. Do you think this is plausible? Explain why or why not.
Ans: Answers will vary.
13. Why does the United States currently have a growing shortage of natural gas?
Ans: Natural gas is in increasing
demand in the U.S. but deposits are often located far from
where the energy is used. Because it is a gas and is less dense than a liquid, natural gas costs four
times more to transport through pipelines than crude oil. To transport natural gas over long
stances, it must first be compressed to form liquefied natural gas (LNG), then carried on
specially constructed refrigerated ships. After LNG arrives at its destination, it must be returned
to the gaseous state at regasification plants before being piped t
o where it will be used. Currently,
the United States has only four such plants, which severely restricts the importation of natural
gas from other countries.
14. What are the five kinds of synfuels? Why are they not being used more extensively?
fuels include tar sands, oil shales, gas hydrates, liquefied coal, and coal gas. Although
synfuels are promising energy sources, they have many of the same undesirable effects as fossil
fuels. Their combustion releases enormous quantities of CO2 and other
pollutants into the
atmosphere, thereby contributing to global warming and air pollution. Some synfuels, such as
coal gas, require large amounts of water during production and are of limited usefulness in arid
areas, where water shortages are already commo
nplace. Also, enormously large areas of land
would have to be surface mined to recover the fuel in tar sands and oil shales.
15. What is resource recovery?
Ans: Resource recovery is the process of removing any material
sulfur or metals, for
polluted emissions or solid waste and selling it as a marketable product.
16. Distinguish among fluidized
bed combustion, coal liquefaction, and coal gasification.
bed combustion is a clean
coal technology in which crushed coal is mixed
limestone to neutralize the acidic sulfur compounds produced during combustion. A nonalcohol
liquid fuel similar to oil can be produced from coal, called coal liquefaction. The liquid fuel,
which is cleaned before burning, is less polluting than solid
coal. Coal gasification is production
of the combustible gas methane from coal by reacting it with air and steam
17. Give three reasons why the United States needs a comprehensive national energy policy.
Ans: The United States has a comprehensive energy
policy for several reasons: (1) The supply of
fossil fuels is limited; (2) the production, transport, and use of fossil fuels pollute the
environment; and (3) our heavy dependence on foreign oil makes us economically vulnerable.
18. Fossil fuels are “no
renewable” resources. Why is this a problem from a systems
Ans: Consuming fossil fuels at the current rate is not sustainable. We will use up our supply of
these resources and be unable to replace them. Taking a systems perspective
for long term cause and effect relationships and sustainability
might lead to a more efficacious
Answers to Review Questions
Energy Sources and Consumption (p. 235)
1. How does per capita energy consumption compare in highly de
veloped and developing
Ans: A conspicuous difference in per capita energy consumption exists between highly
developed and developing nations. Highly developed nations consume much more energy per
person than developing nations.
Fossil Fuels (
1. What are fossil fuels?
Ans: Fossil fuels are combustible deposits in Earth’s crust, composed of the remnants (fossils) of
prehistoric organisms that existed millions of years ago. Coal, oil (petroleum) and natural gas are
the three types of fo
2. How are coal, oil, and natural gas formed?
Ans: Areas where fossil fuels formed were vast swamps, rich in plant life. As the plants died,
they fell into the swamp and were covered by water, where decomposition was slow. Over time,
more dead plants piled up. As a result of periodic changes in sea level, layers of
sediment accumulated, forming layers that covered the plant material. Aeons passed, and the heat
and pressure that accompanied burial converted the nondecomposed plant mater
ial into a carbon
rich rock called coal and the layers of sediment into sedimentary rock. Oil formed when large
numbers of microscopic aquatic organisms died and settled in the sediments. As these organisms
accumulated, their decomposition depleted the sma
ll amount of oxygen present in the sediments.
The resultant oxygen
deficient environment prevented further decomposition. Over time, the
dead remains were covered and buried deeper in the sediments. Natural gas composed primarily
of the simplest hydrocarb
on, methane, formed in essentially the same way as oil, only at higher
temperatures, typically greater than 100 °C.
Coal (p. 243)
1. What are the advantages and disadvantages of using coal as an energy resource?
Ans: The United States has 25% of the wo
rld's coal supply in its massive deposits. These
supplies are projected to last at least 200 years at current consumption levels. However, coal
mining poses risks to human health and environmental health. The burning of coal also releases
many pollutants i
nto the air.
2. Which type of coal mining
surface or subsurface mining
is more land
Ans: Surface mining disrupts the land much more extensively than subsurface mining and has
the potential to cause several serious environmental problems.
hat are acid mine drainage and acid deposition?
Ans: Acid mine drainage is pollution caused when sulfuric acid and dangerous dissolved
materials such as lead, arsenic and cadmium wash from coal and metal mines into nearby lakes
and streams. Acid depositio
n is a type of air pollution in which acid falls from the atmosphere to
the surface as precipitation (acid precipitation) or as dry acid particles.
4. What are the environmental benefits of resource recovery? of fluidized
Ans: In resource
recovery the sludge is treated as a marketable product rather than as a polluted
emission. These products can be sold to other industries and stay out of landfills. Fluidized
combustion takes place at a lower temperature than regular coal burning, and
oxides are produced. Because the sulfur in coal reacts with the calcium in limestone to form
calcium sulfate, which then precipitates out, sulfur is removed from the coal during the burning
process, so scrubbers are not needed to remove it
Oil and Natural Gas (p. 251)
1. What are two examples of structural traps?
Ans The strata that arch upward include both porous and impermeable rock. If impermeable
layers overlie porous layers, any oil or natural gas present from a so
urce rock such as shale may
work its way up through the porous rock to accumulate under the impermeable layer. Many
important oil and natural gas deposits are found in association with salt domes, underground
columns of salt. The ascending salt dome, toget
her with the rock layers that buckle over it,
provides a trap for oil or natural gas.
2. What are three environmental problems associated with using oil and natural gas as energy
Ans: Two sets of environmental problems are associated with the
use of oil and natural gas: the
problems that result from burning the fuels (combustion) and the problems involved in obtaining
them (production and transport). The burning of oil and natural gas produces CO2. As CO2
accumulates in the atmosphere, it insul
ates the planet, preventing planetary heat from radiating
back into space. Another negative environmental impact of burning oil is acid deposition. One of
the concerns in oil and natural gas production is the environmental damage that may occur
r transport, often over long distances by pipelines or ocean tankers. A serious spill
along the route creates an environmental crisis, particularly in aquatic ecosystems, where the oil
slick can travel.
3. What is the controversy surrounding the Arctic Na
tional Wildlife Refuge?
Ans: On one side are those who seek to protect rare and fragile natural environments; on the
other side are those whose higher priority is the development of some of the last major U.S. oil
supplies. Supporters cite economic consid
erations as the main reason for drilling for oil in the
refuge. The United States is spending a large proportion of its energy budget to purchase foreign
oil. Development of domestic oil would improve the balance of trade and make us less dependent
ign countries for our oil. Conservationists think oil exploration poses permanent threats to
the delicate balance of nature in the Alaskan wilderness, in exchange for a temporary oil supply.
They reason that the money spent drilling for oil would be better
used for research into
alternative, renewable energy sources and energy conservation
a more permanent solution to the
Synfuels and Other Potential Fossil Fuel Resources (p. 252)
1. What are tar sands and oil shales?
Ans: Tar sands, or
oil sands, are underground sand deposits permeated with bitumen, a thick,
like oil. Oil shales are sedimentary rocks containing a mixture of hydrocarbons known
collectively as kerogen.
2. What are liquid coal and coal gas?
Ans: Through a process
called coal liquefaction, a nonalcohol liquid fuel similar to oil can be
produced from coal. The liquid fuel, which is cleaned before burning, is less polluting than solid
coal. Coal gas is another synfuel, a gaseous product of coal. Coal gasification is
the combustible gas methane from coal by reacting it with air and steam
3. How do the environmental problems associated with the use of synfuels compare to those of
coal, oil, and natural gas?
Ans: Although synfuels are promising energy sou
rces, they have many of the same undesirable
effects as fossil fuels. Their combustion releases enormous quantities of CO2 and other
pollutants into the atmosphere, thereby contributing to global warming and air pollution. Some
synfuels, such as coal gas,
require large amounts of water during production and are of limited
usefulness in arid areas, where water shortages are already commonplace. Also, enormously
large areas of land would have to be surface mined to recover the fuel in tar sands and oil shales
The U.S. Energy Strategy (p. 255)
1. What are subsidies? How do they affect energy prices and use?
Ans: A subsidy is a form of government support (such as public financing or tax breaks) given to
a business or institution to promote that group’s
activity. Subsidies keep energy prices artificially
low because the government thinks they are beneficial to the economy. When prices reflect the
true costs of energy, including the environmental costs incurred by its production, transport, and
is used more efficiently.
2. What are the main points in President George W. Bush's National Energy Policy?
Ans: President Bush’s policy has five components: (1) modernize conservation; (2) modernize
our energy infrastructure; (3) increase energy suppli
es; (4) accelerate the protection and
of the environment; and (5) increase our nation's energy security.