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Chapter 19
Climate Disruption
Chapter Outline
CORE CASE STUDY Melting Ice in Greenland
19-1 How Is the Earth’s Climate Changing?
19-2 Why Is the Earth’s Climate Changing?
SCIENCE FOCUS Using Models to Project Future Changes in Atmospheric Temperatures
19-3 What Are the Possible Effects of a Warmer Atmosphere?
Individuals matter Konrad Steffen: Studying Melting Ice in Greenland
19-4 What Can We Do to Slow Projected Climate Disruption?
SCIENCE FOCUS Have Climate Scientists Been Too Conservative?
SCIENCE FOCUS Is Capturing and Storing CO2 the Answer?
19-5 How Can We Adapt to Climate Change?
TYING IT ALL TOGETHER Melting Ice in Greenland and Sustainability
Key Concepts
19-1 Considerable scientific evidence indicates that the earth’s atmosphere is warming at a rapid rate that
is likely to lead to significant climate disruption during this century.
19-2 Scientific evidence strongly indicates that the earth’s atmosphere has been warming at a rapid rate
since 1975 and that human activities, especially the burning of fossil fuels and deforestation, have played
a major role in this warming.
19-3 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.
19-4 We can reduce greenhouse gas emissions and the threat of climate disruption while saving money
and improving human health if we cut energy waste and rely more on cleaner renewable energy
resources.
19-5 While we can prepare for some climate change that is now inevitable, we could realize important
economic, ecological, and health benefits by drastically reducing greenhouse gas emissions with the goal
of slowing projected climate disruption.
Key Questions and Concepts
CORE CASE STUDY: Melting ice in Greenland. Greenland’s ice is melting at a slow and accelerating
rate. If Greenland’s glaciers melt, it could raise sea level dramatically. The IPCC projects that global sea
level is likely to rise by 7-23 inches this century. Other scientists suggest that sea level rise will be much
greater.
19-1 How Is the Earth’s Climate Changing?
A. Temperature and climate have been changing throughout the earth’s history. Climate shifts have
occurred due to volcanic emissions, changes in solar input, continents moving on shifting plates,
meteor strikes, and other factors. Alternating cycles of freezing and thawing are known as
glacial and interglacial periods.
Instructor's Manual: Chapter 19
B. Geologic records and atmospheric measurements provide a wealth of information about past
atmospheric temperatures and climate. On average, over the past 900,000 years, there has been a
cycle of global cooling and global warming. The cycles are known as glacial and interglacial
periods.
19-2 Why Is the Earth’s Climate Changing?
C. Certain gases in the atmosphere absorb heat and warm the lower atmosphere. A natural process
called the greenhouse effect warms the lower troposphere and surface.
D. The four major greenhouse gases in the lower atmosphere are water vapor, carbon dioxide,
methane, and nitrous oxide.
E. Climate change and human activities.
1. Humans have increased levels of greenhouse gases in the troposphere by use of fossil fuels,
farming, use of inorganic fertilizers, burning forests, etc. Burning of fossil fuels has generated
much of the CO2 increase. Methane emissions have risen as a result of raising livestock,
extracting fossil fuels, creating landfills, and creating reservoirs. Nitrous oxide has risen
because if increased use of nitrogen fertilizers.
2. There is evidence that the earth’s troposphere is warming, mostly because of human actions.
The Intergovernmental Panel on Climate Change (IPCC) was formed in 1988 to evaluate
possible future climate changes. The major findings of the IPCC are:
a. The earth’s lower atmosphere is warming.
b. Most of the increase in greenhouse gases is due to human activities.
c. Changes in the atmosphere are beginning to change the climate.
d. If greenhouse gas concentrations continue to rise, there will likely be rapid climate
disruption.
e. This disruption will likely cause ecological, economic, and social disruption.
F. Carbon dioxide concentrations play an important role in determining the average temperature of
the atmosphere.
SCIENCE FOCUS: Using models to project future changes in atmospheric temperatures. To
make predictions about how temperature will change in the future, scientists develop complex
mathematical models to simulate many factors. These are projections of what is likely, as opposed
to predictions.
1. Exceeding carbon dioxide levels of 450 ppm may push us beyond an irreversible tipping
point.
2. The largest carbon dioxide emitters are China, the United States and the European Union.
G. It is thought that most of the rise in temperature since 1980 could not be the result of increased
solar output.
H. Oceans lose some of their ability to remove carbon from the atmosphere as their temperatures
rise. Oceans are also becoming more acidic because of increasing levels of carbon dioxide.
I. The role of clouds in warming the atmosphere is largely unknown.
J. Aerosols may temporarily slow warming by reflecting sunlight and serving as condensation
nuclei for clouds.
19-3 What Are the Possible Effects of a Warmer Atmosphere?
A. Most historic changes in the temperature of the lower atmosphere took place over thousands of
years. Today we face a rapid projected increase.
B. Severe droughts may increase. This may cause an increase in wildfires, declines inaccessible
surface water and declining biodiversity.
C. The melting of some of the world’s ice means that less sunlight is reflected back into space, and
helps warm the troposphere further. Mountain glaciers are a major source of fresh water and
they are shrinking.
Instructor's Manual: Chapter 19
D. Permafrost will likely melt, emitting significant amounts of methane and carbon dioxide into the
atmosphere.
E. Sea levels are rising faster than expected, and will likely rise 3-6.5 feet by the end of the century.
This will cause severe flooding and destruction of habitat.
F. Atmospheric warming will increase the incidence of extreme weather events, including droughts,
floods and tropical storms.
G. A warmer troposphere will change the distribution and population sizes of wild species, shift
locations of ecosystems, and threaten some protected reserves and coral reefs.
H. Climate change will lead to a decline in agriculture in some areas, particularly those that
emphasize monoculture production, whereas productivity will increase for other areas.
I. Health implications are likely as insects, microbes and other organisms begin to expand their
ranges.
19-4 What Can We Do to Slow Projected Climate Disruption?
A. Climate change is hard to deal with because it has many causes, its effects are uneven and longterm, and there is disagreement over what should be done.
1. The problem is global.
2. The problem is a long-term political issue.
3. The harmful and beneficial impacts of climate change are not spread evenly.
4. Many actions that might reduce the threat of climate change, such as phasing out fossil fuels,
are controversial because they can disrupt economics and lifestyle.
5. Humans may not be hardwired to respond to long-term threats.
SCIENCE FOCUS: Have climate scientists been too conservative? At a time when the IPCC
achieved unprecedented agreement about climate change, the percentage of the general public that
believes this issue is over-exaggerated has increased. This is due to deliberate politicizing, as well as
playing on the public’s lack of knowledge about how science works and their lack if knowledge of
the difference between weather and climate.
B. Four major prevention strategies that could reduce carbon dioxide emissions dramatically are:
1. Improve energy efficiency
2. Shift to low-carbon renewable energy resources
3. Stop deforestation
4. Shift to more sustainable agriculture
C. There are several strategies for removing carbon dioxide from the atmosphere. These include:
1. A massive tree-planting program
2. Wetland restoration
3. Plant large areas with fast growing perennial plants
4. Preservation and restoration of forests
5. Seeding oceans to promote growth of marine algae
6. Carbon capture and storage
D. Geoengineering provides another option.
1. Launching sulfates into the atmosphere may lead to cooling.
2. Using pipes to pump nutrient-rich water from the deep oceans to fertilize algae on the surface
would also remove carbon dioxide from the atmosphere.
SCIENCE FOCUS: Is capturing and storing CO2 the answer? Carbon capture and storage refers
to schemes to remove carbon dioxide from power plants and industrial facilities and store it
underground. Large scale leaks could potentially lead to severe climate disruption. Many contend
that this is a risky output solution.
E. Governments can use six methods to deal with climate change.
1. Strictly regulate carbon dioxide and methane as air pollutants
2. Impose carbon taxes or fees
3. Place a cap on total emissions and institute cap-and-trade
Instructor's Manual: Chapter 19
F.
G.
H.
I.
4. Increase subsidies to energy efficient technologies
5. Fund the transfer of green technologies from more-developed to less-developed countries
6. Create programs to help curb population growth
The Kyoto Protocol, developed in 1997, would require 38 developed countries to cut emissions of
some gases by about 5.2% below 1990 levels by 2012.
Costa Rica aims to be the world’s first carbon neutral nation. Analysts urge rapidly developing
nations such as China and India to make a shift toward sustainability.
There needs to be 50-85% reductions in emissions by 2050 to avoid projected harmful effects.
As this is unlikely, we must prepare for the harmful effects.
The no-regrets strategy for dealing with climate change suggests that actions directed at
addressing the issue will have important environmental, health, and economic benefits.
19-5 How Can We Adapt to Climate Change?
A. We can prepare for climate disruption.
B. The world would need to make a 50-85% cut in emissions of greenhouses gases by 2050 to
stabilize concentrations of these gases in the atmosphere.
C. Several cities have developed adaptation plans for climate change.
D. The no-regrets strategy maintains that even if climate change turns out to be less of a problem,
implementing many changes now will be beneficial in the end.
a. By relying on a mix of renewable, domestic energy resources will help many countries
cut their costly dependence on fossil fuels.
Teaching Tips
Large Lecture Classes:
There are some basic misunderstandings about ozone depletion, ozone pollution, and climate change.
These can be helpful to address directly through a series of questions such as “Does air pollution help the
ozone layer?” or “Does the ozone hole cause climate change?”. The key concepts to highlight here are
that tropospheric ozone is different from stratospheric ozone, and that the ozone “hole” is not the cause of
climate change. Although ozone depletion can affect atmospheric circulation and energy exchange, these
effects are small relative to the direct effects of greenhouse gases, and students should clearly understand
this. To increase interest in the class, you could start the class with five minutes from the “Inconvenient
Truth” or from the “Day After Tomorrow.” Although the “Day after Tomorrow” is highly fictionalized,
there are interesting core ideas embedded in the film (e.g., thermohaline circulation) that are worth talking
about.
Smaller Lecture Classes:
Watch the first half hour of the “Day After Tomorrow.” Have students interrupt the film when they see
information that is factually correct and information that is inaccurate. Have a discussion about fact
versus fiction in movies such as this. If you need more information about the movie and what is
accurately portrayed, see http://www.realclimate.org.
Key Term
Carbon capturing and storage (CCS)
Instructor's Manual: Chapter 19
Term Paper Topics
1.
Variables that affect global warming: greenhouse gases, the climate system, the biosphere, volcanic
eruptions, oceans, air pollution influences.
2.
Potential effects of global warming: global warming and our coastlines; global warming and the
incidence of severe storms; deforestation and global warming; climate and biodiversity; rates of
global climate change and adaptation; global warming and agriculture.
3.
Ozone depletion: varying patterns of ozone depletion in the northern and southern hemispheres;
health effects of increased ultraviolet radiation (skin cancer, cataracts); distinguishing tropospheric
and stratospheric ozone; CFCs: uses and control of production.
4.
Do humans have a commitment to future generations? If so, how should this commitment be
addressed in national or international greenhouse gas legislation/accords?
5.
How much are humans willing to spend for energy efficiency in the short term to receive long-term
economic payoffs and help slow potential global warming? What is the government’s role in these
decisions, if any?
6.
Should humans act to prevent global warming or adapt to global warming as it happens?
7.
How can developed countries prevent developing countries from making the same environmental
mistakes they did during their own industrial transition?
8.
How was the Antarctic ozone hole discovered? What does this tell us about science?
9.
What are the pros and cons of fossil fuel emission reductions versus carbon sequestration? Should
we favor one approach over the other?
10. What are the pros and cons of a carbon tax versus a carbon cap and trade system? Which system
would be better for the U.S.?
Instructor's Manual: Chapter 19