5. Do you feel that humans have the power to alter Earth’s climate? Do you feel that humans can
responsibly control their impact on the atmosphere?
6. Have you ever breathed pristine air? How did it feel?
7. Have you ever breathed highly polluted air? How did it feel?
8. Do humans have a right to breathe clean air?
Laboratory Skills
Wells, Edward. Lab Manual for Environmental Science. 2009. Lab #17: Measuring Total Suspended
Particulates.
Wells, Edward. Lab Manual for Environmental Science. 2009. Lab #21: Why is Your Footprint so Big?
News Videos
New Ideas for Dealing with Climate Change, The Brooks/Cole Environmental Science Video Library
2009, ©2011, DVD ISBN-13: 978-0-538-73355-7
Additional Video Resources
Clearing California’s Skies (Video, Online)
Instructor’s Manual for Environmental Science, 15th edition
Nova: Dimming the Sun (PBS series)
Forecast Earth: Air Aware
An EPA-sponsored segment, Air Aware, highlights how air quality can affect people.
http://www.airnow.gov/index.cfm?action=movies.index
NOVA: Can Buildings Make You Sick? (PBS series)
Scientific American Frontiers—Hot Planet—Cold Comfort (Scientific American Frontiers, TV series,
2005)
http://www.pbs.org/saf/1505/
Strange Days on Planet Earth (TV Series, National Geographic, 2008)
http://www.pbs.org/strangedays/
NOVA: What’s Up with the Weather? (PBS series)
Web Resources
Climate Crisis
Information about climate change and Al Gore’s documentary An Inconvenient Truth.
http://www.climatecrisis.net/
Chapter 15: Air Pollution, Climate Disruption, and Ozone Depletion
Rocky Mountain Institute
Nonprofit research and educational foundation aiming to foster efficient and sustainable use of resources.
http://www.rmi.org/rmi/
Current U.S. Air Quality Assessments
http://www.airnow.gov
Digital Integration
Correlation to Global Environment Watch
Acid Rain Global Geoscience Watch: Oceanography
Air Pollution Global Geoscience Watch: Meteorology
Antarctica Greenhouse Gas Emissions
Arctic Circle Human Health
Correlation to Explore More
Air Pollution Coal Environmental Politics
China Energy Ozone Depletion
Climate Change Environmental and Human Health Science
Instructor’s Manual for Environmental Science, 15th edition
Correlation to Virtual Field Trips
Climate Change and Extinction
Suggested Answers to End of Chapter Questions
Answers will vary but these represent phrases from this chapter. The following are examples of the material
that should be contained in possible student answers to the end of chapter questions. They represent only a
Review
Core Case Study
1. Summarize the story of Greenland’s melting glaciers and the possible effects of this process. Explain
how it fits into projections about climate change during this century.
Areas of Greenland’s ice have been melting at an accelerating rate during Greenland’s summers
(Figure 15.1). Considerable scientific evidence indicates that a key factor in this melting is
atmospheric warming—the gradual rise of the average temperature of the atmosphere near the
Section 15-1
2. What is the key concept for this section? Define troposphere, stratosphere, and ozone layer.
Define and give two examples of greenhouse gases. Why is the ozone layer important?
• CONCEPT 15-1 The two innermost layers of the atmosphere are the troposphere, which supports
life, and the stratosphere, which contains the protective ozone layer.
• The troposphere is the atmospheric layer closest to the earth’s surface. This layer extends only
Chapter 15: Air Pollution, Climate Disruption, and Ozone Depletion
Section 15-2
3. What are the two key concepts for this section? What is air pollution? Distinguish between primary
pollutants and secondary pollutants and give an example of each. List the major outdoor air
pollutants and their harmful effects. Distinguish between industrial smog and photochemical smog.
List and briefly describe five natural factors that help to reduce outdoor air pollution and six natural
factors that help to worsen it. What is a temperature inversion and how can it affect air pollution
levels? What is acid deposition, how does it form, and what are its major environmental impacts on
vegetation, lakes, human-built structures, and human health? List three major ways to reduce acid
deposition.
See pages 376–382.
• CONCEPT 15-2A Three major outdoor air pollution problems are industrial smog primarily from
burning coal, photochemical smog from motor vehicle and industrial emissions, and acid
deposition from coal burning and motor vehicle exhaust.
• CONCEPT 15-2B The most threatening indoor air pollutants are smoke and soot from wood and
coal fires (mostly in less-developed countries), cigarette smoke, and chemicals used in building
materials and cleaning products.
• Carbon dioxide (CO2) is a colorless, odorless gas that contributes to climate change.
• Nitric oxide (NO) is a colorless gas that forms in automobile engines and coal-burning power and
industrial plants. In the air, NO reacts with oxygen to form nitrogen dioxide (NO2). Collectively,
NO and NO2 are called nitrogen oxides (NOX). Some of the NO2 reacts with water vapor in the air
to form nitric acid (HNO3) and nitrate salts (NO3–)—components of harmful acid deposition,. Both
NO and NO2 play a role in the formation of photochemical smog—a mixture of chemicals formed
under sulfur dioxide and sulfuric acid. At high enough levels, nitrogen oxides can irritate the eyes,
nose, and throat, aggravate lung ailments such as asthma and bronchitis, suppress plant growth,
and reduce visibility when they are converted to nitric acid and nitrate salts
• Sulfur dioxide (SO2) is a colorless gas with an irritating odor. In the atmosphere, SO2 can be
converted to aerosols, which consist of microscopic suspended droplets of sulfuric acid (H2SO4)
and suspended particles of sulfate (SO4 2–) salts that return to the earth as a component of acid
deposition. Sulfur dioxide, sulfuric acid droplets, and sulfate particles reduce visibility and
aggravate breathing problems. They can also damage crops, trees, soils, and aquatic life in lakes;
and they corrode metals and damage paint, paper, leather, and stone on buildings and statues.
Instructor’s Manual for Environmental Science, 15th edition
to colds and pneumonia, and irritate the eyes, nose, and throat.. It also damages plants, rubber in
tires, fabrics, and paints.
• Organic compounds that exist as gases in the atmosphere or that evaporate into the atmosphere are
called volatile organic compounds (VOCs). Examples are hydrocarbons emitted by the leaves of
many plants, and methane (CH4), a greenhouse gas that is 20 times more effective per molecule
than CO2 at warming the atmosphere through the greenhouse effect.
• Six factors can increase outdoor air pollution. First, urban buildings slow wind speed and reduce
dilution and removal of pollutants. Second, hills and mountains reduce the flow of air in valleys
below them and allow pollutant levels to build up at ground level. Third, high temperatures
promote the chemical reactions leading to formation of photochemical smog. Fourth, emissions of
volatile organic compounds from certain trees and plants in heavily wooded urban areas can play a
large role in the formation of photochemical smog. A fifth factor—the so-called grasshopper
effect—occurs when air pollutants are transported by evaporation and winds from tropical and
temperate areas through the atmosphere to the earth’s polar areas, where they are deposited. Sixth,
temperature inversions can cause pollutants to build to high levels. During daylight, the sun warms
the air near the earth’s surface. Under certain atmospheric conditions, a layer of warm air can
temporarily lie atop a layer of cooler air nearer the ground, creating a temperature inversion. The
air near the surface does not rise and mix with the air above and pollutants can build up to harmful
and even lethal concentrations in the stagnant layer of cool air near the ground.
• Ways to reduce acid deposition and its damage include: reducing coal use, burning low-sulfur
coal, increasing natural gas use, increasing use of renewable energy resources, removing SO2
particulates and NOx from smokestack gases, removing NOx from motor vehicular exhaust, taxing
emissions of SO2, and adding lime or phosphate to neutralize acidified lakes.
4. What is the most threatening indoor air pollutant in many less-developed countries? What are the four
most dangerous indoor air pollutants in more-developed countries? Briefly describe the human body’s
defenses against air pollution, how they can be overwhelmed, and illnesses that can result. In the world
and in the United States, about how many people die prematurely from air pollution each year?
• In less-developed countries, the indoor burning of wood, charcoal, dung, crop residues, coal, and
other cooking and heating fuels in open fires or in unvented or poorly vented stoves exposes
Chapter 15: Air Pollution, Climate Disruption, and Ozone Depletion
Section 15-3
5. What is the key concept for this section? Summarize the accomplishments of air pollution control
laws in the United States and discuss how they can be improved. List the advantages and
disadvantages of using an emissions trading program to reduce outdoor air pollution. Summarize the
major ways to reduce emissions from power plants and motor vehicles. What are four ways to reduce
indoor air pollution?
• CONCEPT 15-3 Legal, economic, and technological tools can help us to clean up air pollution,
but the best solution is to prevent it.
• According to a 2009 EPA report, the combined emissions of the six major pollutants decreased by
about 54% between 1980 and 2008, even with significant increases during the same period in
gross domestic product, vehicle miles traveled, energy consumption, and population.
• U.S. air pollution laws could be strengthened by:
o Putting much greater emphasis on preventing air pollution.
• Advantages of using an emissions trading program to reduce outdoor air pollution are that it is
cheaper and more efficient than government regulation of air pollution control. Critics of this
approach contend that it allows utilities with older, dirtier power plants to buy their way out of
Instructor’s Manual for Environmental Science, 15th edition
Section 15-4
6. What is the key concept for this section? Define and distinguish between weather and climate. Why is
“global warming” a misleading term? Summarize the trends in atmospheric warming and cooling
during the past 900,000 years. What has happened to the atmosphere’s temperature near the earth’s
surface since 1975? How do scientists get information about past temperatures and climates? List three
major conclusions of the IPCC and other scientific bodies regarding changes in the temperature of the
earth’s atmosphere. List nine pieces of scientific evidence that support the conclusion that human–
influenced climate change is happening now.
• CONCEPT 15-4 Considerable scientific evidence indicates that the earth’s atmosphere is warming
because of a combination of natural effects and human activities, and that this warming is likely to
lead to significant climate disruption during this century.
• Weather consists of short-term changes in atmospheric variables such as the temperature,
precipitation, wind, and barometric pressure in a given area over a period of hours or days. By
contrast, climate is determined by the average weather conditions of the earth or of a particular
• Most of the recent overall rapid rise in the global average atmospheric temperature on land has
taken place since 1978 (Figure 15.19). According to the 2014 study on climate change by the
American Association for the Advancement of Science (AAAS), evidence from numerous
scientific studies indicates that rising inputs of greenhouse gases from human activities are
overwhelming the combined effects of natural factors that led to climate change in the past.
• Past temperature changes are estimated by analysis of radioisotopes in rocks and fossils; tiny
Chapter 15: Air Pollution, Climate Disruption, and Ozone Depletion
• Evidence:
o Between 1906 and 2013, the earth’s average global surface temperature has risen by
about 0.8C° (1.4F°), with much of this increase taking place since the mid-1970s (Figure
15.19).
o Nine of the ten warmest years on record since 1861 have taken place since 2000.
o In some parts of the world, glaciers that have existed for thousands of years are melting
(Figure 15.21 and Core Case Study).
o In the Arctic, floating summer sea ice has been shrinking significantly.
000). Species that cannot migrate face extinction.
7. What is the greenhouse effect and why is it so important to life on the earth? What role do CO2
emissions play in atmospheric warming and what are two major sources of these emissions? Define
carbon footprint. Explain how scientists use models to project future changes in atmospheric
temperatures. Describe how each of the following might affect average atmospheric temperatures and
projected climate change during this century: (a) the oceans, (b) cloud cover, and (c) outdoor air pollution.
• A natural process called the greenhouse effect plays a key role in determining the earth’s climate. It
occurs when some of the solar energy absorbed by the earth radiates into the atmosphere as infrared
radiation (heat). As this radiation interacts with molecules in the air—especially the four greenhouse
gases, water vapor (H2O), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)—it increases
their kinetic energy and warms the lower atmosphere and the earth’s surface, helping to create a livable
climate.
Instructor’s Manual for Environmental Science, 15th edition
Section 15-5
8. What is the key concept for this section? Summarize the projections of scientists on how climate
change is likely to affect each of the following during this century: ice and snow cover, permafrost,
sea levels, severe drought, extreme weather events, biodiversity, food production, human health and
economies, and national security.
• CONCEPT 15-5 The projected rapid change in the atmosphere’s temperature could have severe and
long-lasting consequences, including increased drought and flooding, rising sea levels, and shifts in
the locations of croplands and wildlife habitats.
• By 2059, up to 45% of the world’s land area could be experiencing extreme drought.
• More ice and snow are likely to melt. Climate change is predicted to be the most severe in the
Section 15-6
9. What is the key concept for this section? What are five reasons why dealing with projected climate
change is a difficult problem? Define climate change tipping point, and list five possible examples.
What are two basic approaches to dealing with climate change? List five major prevention strategies
Chapter 15: Air Pollution, Climate Disruption, and Ozone Depletion
and four cleanup approaches for slowing projected climate change. List seven pieces of good news
related to dealing with climate change. What is carbon capture and storage (CCS)? List three problems
associated with capturing and storing carbon dioxide emissions. Define geoengineering and describe
two proposed geoengineering strategies for dealing with the threat of climate change. What are the main
potential problems with relying on such strategies? List seven things that governments can do to help
slow projected climate change. What are the major advantages and disadvantages of using (a) carbon or
energy taxes and (b) a cap-and-trade system for reducing the threat of climate change? What is the
Kyoto Protocol and how effective has it been in dealing with the threat of climate change? Describe
what some countries, cities, major corporations, and colleges and universities have done to reduce their
carbon footprints. List five ways in which you can reduce your carbon footprint. List five ways in
which we can prepare for the possible long-term harmful effects of projected climate change.
• CONCEPT 15-6 We can reduce greenhouse gas emissions and the threat of climate change while
saving money and improving human health if we cut energy waste and rely more on cleaner
renewable energy resources.
• Five reasons why dealing with projected climate change is difficult:
▪ The problem is global
▪ The problem is a long-term political issue.
▪ The projected effects are uncertain.
• Climate change tipping points are thresholds beyond which natural systems can change
irreversibly. Some of the tipping points that scientists are most concerned about are:
o Atmospheric carbon level of 450 ppm
• Carbon capture and storage (CCS) is the removal of some of the CO2 from smokestacks to pump
it deep underground into abandoned coal beds and oil and gas fields, or to liquefy it and inject it
into sediments under the sea floor.
• Four prevention strategies are:
o
Improve energy efficiency to reduce fossil fuel use, especially the use of coal.
o
Shift from nonrenewable carbon-based fossil fuels to a mix of low-carbon
• CCS is an output, or cleanup, strategy, not a preventive one. Stored CO2 would have to remain
sealed from the atmosphere forever. Any large-scale leaks caused by earthquakes or other shocks,
as well as any number of smaller continuous leaks from CO2 storage sites around the world, could
Instructor’s Manual for Environmental Science, 15th edition
• Geoengineering strategies try to manipulate certain natural conditions to help counter an enhanced
greenhouse effect. Two examples are injecting sulfate particles into the stratosphere to reflect some
of the incoming sunlight into space and cool the troposphere, and placing a series of giant mirrors in
orbit above the earth to reflect incoming sunlight for the same purpose.
• Governments can:
o
Strictly regulate carbon dioxide (CO2) and methane (CH4) as climate-changing pollutants.
o
Phase out the most inefficient polluting coal-burning power plants and replace them with
more efficient and cleaner natural gas and renewable energy alternatives such as wind
power.
• According to the 2014 IPCC report, there is much good news related to dealing with the threat of
climate change:
o
We know how to engineer zero-carbon buildings and how to reduce the carbon footprints
of existing buildings.
o
If we increase the use of hybrid, plug-in hybrid, and electric cars, while charging their
batteries only with electricity produced from renewable energy sources, we will greatly
• Some analysts praise the Kyoto agreement as a small but important step in attempting to slow
projected climate change. Others see the agreement as a weak and slow response to an urgent global
problem.
• Some nations are leading others in facing the challenges of climate change. Costa Rica aims to be the
first country to become carbon neutral by cutting its net carbon emissions to zero by 2030. Norway
aims to become carbon neutral by 2050. By 2009, some 30 U.S. states had greenhouse gas emission
Chapter 15: Air Pollution, Climate Disruption, and Ozone Depletion
faculty at Oberlin College in the U.S. state of Ohio have asked their board of trustees to reduce the
college’s CO2 emissions to zero by 2020 by buying or producing renewable energy. In the U.S. state of
Pennsylvania, 25 colleges have joined to purchase wind power and other forms of mostly carbon-free
renewable energy.
• See Figure 15-34. You can reduce your annual emissions of CO2.
o Calculate your carbon footprint.
o Drive a fuel-efficient car, walk, bike, carpool, and use mass transit.
• Many analysts believe that while we work to slash emissions, we should also begin to prepare for the
likely harmful effects of projected climate disruption. For example, relief organizations such as the
International Red Cross are turning their attention to projects such as expanding mangrove forests as
buffers against storm surges, building shelters on high ground, and planting trees on slopes to help
Section 15-7
10. What are the two key concepts for this section? How have human activities depleted ozone in the
stratosphere? List five harmful effects of such depletion. Explain how scientists Sherwood Roland
and Mario Molina helped to awaken the world to this threat. What has the world done to help reduce
the threat of ozone depletion in the stratosphere? What are the three big ideas for this chapter?
Explain how we can apply the six principles of sustainability can be applied to dealing with the
problems of air pollution, climate change, and ozone depletion.
See pages 404-407.
• CONCEPT 15-7A Widespread use of certain chemicals has reduced ozone levels in the
stratosphere, which has allowed more harmful ultraviolet radiation to reach the earth’s surface.
Instructor’s Manual for Environmental Science, 15th edition
o Immune system suppression.
• Food and Forests.
o Reduced yields for some crops.
o Reduced seafood supplies from reduced phytoplankton.
o Decreased forest productivity for UV-sensitive tree species.
• Climate Change.
o While in troposphere, CFCs act as greenhouse gases.
• Wildlife.
o Increased eye cataracts in some species.
• In 1987, representatives of 36 nations met in Montreal, Canada, and developed the Montreal
Protocol. This treaty’s goal was to cut emissions of CFCs by about 35% between 1989 and 2000.
After hearing more bad news about seasonal ozone thinning above Antarctica in 1989,
representatives of 93 countries had more meetings and in 1992 adopted the Copenhagen Protocol,
an amendment that accelerated the phase-out of key ozone-depleting chemicals. Substitutes are
available for most uses of CFCs, and others are being developed.
• The three big ideas for this chapter:
o All countries need to step up efforts to control and prevent outdoor and indoor air
pollution.
o Reducing the possible harmful effects of projected rapid climate change during this
Critical Thinking
1. If you had convincing evidence that at least half of Greenland’s glaciers (Core Case Study) were sure
to melt during this century, would you argue for taking serious actions now to slow projected climate
disruption? If so, summarize the arguments you would use. If not, explain why you would be opposed
to such actions.
Answers will vary but will be along the lines of one of the following:
Chapter 15: Air Pollution, Climate Disruption, and Ozone Depletion
2. Suppose someone tells you that carbon dioxide (CO2) should not be classified as an air pollutant
because it is a natural chemical that is part of the carbon cycle and a chemical that we add to the
atmosphere every time we exhale. Would you consider this to be faulty reasoning? Explain.
3. China relies on coal for two-thirds of its commercial energy usage, partly because the country has
abundant supplies of this resource. Yet China’s coal burning has caused major and growing
air pollution problems for the country and for its neighboring nations, and it has contributed to
projected climate change. In addition, pollution generated in China now spreads across the Pacific
Ocean to the west coast of North America. Do you think China is justified in developing its coal
resource aggressively as other countries, including the United States, have done? Explain. If you
think China should sharply reduce its dependence on coal, would you call for the United States
(the world’s second-largest user of coal) to sharply reduce its coal use? Explain.
4. Between 1940 and 1980, the United States faced severe air pollution problems similar to those now
plaguing China. If you live in the United States, list three important ways in which your life would be
different if citizen-led actions during the 1970s and 1980s had not led to the Clean Air Acts of 1970,
1977, and 1990. Which one or more of the six principles of sustainability were applied by the passage
of these acts? Explain.
Student answers will vary, but should recognize that vast improvement of air pollution problems has
occurred as a result of the social movements of the 1960s and 1970s. In addition to the environmental
movement, that era was characterized by other movements against social concerns, most notably civil
rights and anti-war feelings.
Instructor’s Manual for Environmental Science, 15th edition
persecution by local police forces, the Federal Bureau of Investigation (FBI), and other government
agencies. The student movement, the anti-Vietnam War movement, and the gay rights movement never
succeeded in winning the approval of a majority of Americans, at least as measured by public opinion
polls and surveys. Over time, however, the civil rights movement, the environmental movement, and,
more controversially, the women’s movement, did convert a majority of Americans to many of their
views.
5. Explain why you agree or disagree with IPCC scientists and most of the world’s climate scientists that
(a) climate change is happening now, (b) human activities are the dominant cause of this climate
change, and (c) only action by humans can slow down the rate of climate change and avert or delay its
projected harmful environmental, health, and economic effects..
6. Explain why you would support or oppose each of the strategies listed in Figure 15.29 for slowing
projected climate disruption caused by atmospheric warming.
Student’s answers will vary.
Preventive strategies:
▪ Cut fossil fuel use – especially coal
▪ Shift from coal to natural gas
▪ Repair leaky natural gas pipelines and facilities
▪ Improve energy efficiency
7. Some scientists have suggested that, in order to help cool the warming atmosphere, we could annually
Chapter 15: Air Pollution, Climate Disruption, and Ozone Depletion
inject huge quantities of sulfate particles into the stratosphere. This might have the effect of reflecting
some incoming sunlight back into space. Explain why you would support or oppose this
geoengineering scheme.
8. What are three consumption patterns or other aspects of your lifestyle that directly add greenhouse
gases to the atmosphere? Which, if any, of these things would you be willing to give up in order to
help slow projected climate disruption by reducing your carbon footprint and increasing your
beneficial environmental impact?
Student answers will probably vary considerably. One possible answer is given below. .
Three things that I and most of my peers do are: drive, use electricity, and heat and cool our living
spaces. All of these cause the emission of greenhouse gases and other pollutants. These lifestyle
patterns go against the principles of sustainability such as reliance on solar energy, biodiversity,
nutrient recycling, and population. We are using too much fossil fuel rather than renewable energy.
The production of these fossil fuels can harm biodiversity through surface mining and oil drilling both
Global Environment Watch Exercise
Within the GREENR database, use the World Map feature, and under “Browse,” select Climate
Change and click on the pin for Greenland. Find the latest information on the melting of glaciers in
Greenland (Core Case Study). What is the rate of melting of the glaciers and how might this affect sea
levels during this century? Briefly summarize the evidence used by scientists to support their
statements about melting ice in Greenland. Summarize any information you find about ongoing studies
of Greenland’s ice.
• Recent evidence indicates that the rate of melting of glaciers in Greenland has doubled or more in
the last decade. This will increase sea levels within this century. Previous estimates were that the
Instructor’s Manual for Environmental Science, 15th edition
Ecological Footprint Analysis
1. Calculate your carbon footprint. To calculate your emissions, first complete the blank “Personal
Quantity per Year” column as described above. Wherever you cannot provide personal data, use that
listed in the “Typical Quantity per Year” column. Then, for each activity, calculate your annual
consumption (using the units specified in the “Units per Year” column), and multiply your annual
consumption by the associated number in the “Multiplier” column to obtain an estimate of the pounds
of CO2 resulting from that activity, which you will enter in the “Emissions per Year” column. Finally,
2. Compare your emissions with those of your classmates and with the per capita U.S. average of 19.6
metric tons (21.6 tons) of CO2 per person per year. Actually, your answer should be considerably
less—roughly about half the per capita value—because this computation only accounts for direct
emissions. For instance, CO2 resulting from driving a car is included, but the CO2 emitted in
3. Consider and list actions you could take to reduce your carbon footprint by 20%.
Students should provide possible actions they will take to reduce their carbon footprints. These actions
could include reducing their individual transportation footprint by walking and biking more, utilizing