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Lecture Outlines
Chapter 18
The Science behind the
4th Edition
© 2011 Pearson Education, Inc.
This lecture will help you understand:
• The Earth’s climate
• Human influences on
the atmosphere and
• Methods of climate
• Impacts of global
climate change
• Ways we can respond
to climate change
© 2011 Pearson Education, Inc.
Central Case: Rising seas may flood the
• Tourists think the Maldives Islands are a paradise
• Rising seas due to global climate change could
submerge them
- Erode beaches, cause
- Damage coral reefs
• Residents have evacuated the
lowest-lying islands
• Small nations are not the cause
of climate change, yet they
© 2011 Pearson Education, Inc.
What is climate change?
• Climate change is the fastest-developing area of
environmental science
• Climate = an area’s long-term atmospheric conditions
- Temperature, moisture, wind, precipitation, etc.
- Weather = short-term conditions at localized sites
• Global climate change = describes trends and
variations in Earth’s climate
- Temperature, precipitation, storm frequency
• Global warming and climate change are not the same
© 2011 Pearson Education, Inc.
Global warming
• Global warming = an increase in Earth’s average
- Only one aspect of climate change
• Climate change and global warming refer to current
- Earth’s climate has varied naturally through time
• The current rapid climatic changes are due to humans
- Fossil fuel combustion and deforestation
• Understanding climate change requires understanding
how our planet’s climate works
© 2011 Pearson Education, Inc.
The sun and atmosphere keep Earth warm
• Four factors exert the most influence on climate
• The sun = without it, Earth would be dark and frozen
- Supplies most of Earth’s energy
• The atmosphere = without it, Earth’s temperature would
be much colder
• The oceans = shape climate by storing and transporting
heat and moisture
• How Earth spins, tilts, and moves through space
influence how climate varies over long periods of time
© 2011 Pearson Education, Inc.
The fate of solar radiation
• The atmosphere, land, ice, and water absorb 70% of
incoming solar radiation
© 2011 Pearson Education, Inc.
Greenhouse gases warm the lower
• As Earth’s surface absorbs solar radiation, the surface
increases in temperature and emits infrared radiation
• Greenhouse gases = atmospheric gases that absorb
infrared radiation
- Water vapor, ozone, carbon dioxide, nitrous oxide,
methane, halocarbons [chlorofluorocarbons (CFCs)]
• After absorbing radiation, greenhouse gases re-emit
infrared energy, losing some energy to space
• Greenhouse effect = energy that travels downward,
warming the atmosphere and the planet’s surface
© 2011 Pearson Education, Inc.
The greenhouse effect is natural
• Greenhouse gases have always been in the atmosphere
• We are not worried about the natural greenhouse effect
- Anthropogenic intensification is of concern
• Global warming potential = the relative ability of one
molecule of a greenhouse gas to contribute to warming
- Expressed in relation to carbon dioxide (potential = 1)
- Methane is 25 times as potent as carbon dioxide
© 2011 Pearson Education, Inc.
Carbon dioxide is of primary concern
• It is not the most potent greenhouse gas, but it is
extremely abundant
- The major contributor to the greenhouse effects
• CO2 exerts six times more impact than methane, nitrous
oxide, and halocarbons combined
• Deposition, partial decay, and compression of organic
matter (mostly plants) in wetlands or marine areas led to
formation of coal, oil, and natural gas
- These deposits remained buried for millions of years
© 2011 Pearson Education, Inc.
What caused levels of CO2 to increase?
• Burning fossil fuels transfer CO2 from lithospheric
reservoirs into the atmosphere
- The main reason atmospheric carbon dioxide
concentrations have increased so dramatically
• Deforestation contributes to rising atmospheric CO2
- Forests serve as reservoirs for carbon
- Removing trees reduces the carbon dioxide absorbed
from the atmosphere
• Human activities increased atmospheric CO2 from 280
parts per million (ppm) to 389 ppm
- The highest levels in more than 800,000 years
© 2011 Pearson Education, Inc.
Fluxes of carbon dioxide
© 2011 Pearson Education, Inc.
Other greenhouse gases add to warming
• Methane = fossil fuels, livestock, landfills, crops (rice)
- Levels have doubled since 1750
• Nitrous oxide = feedlots, chemical manufacturing plants,
auto emissions, and synthetic nitrogen fertilizers
• Ozone levels have risen 36% due to photochemical smog
• Halocarbon gases (CFCs) are declining due to the
Montreal Protocol
• Water vapor = the most abundant greenhouse gas
- Contributes most to the natural greenhouse effect
- Concentrations have not changed
© 2011 Pearson Education, Inc.
U.S. emissions of major greenhouse gases
© 2011 Pearson Education, Inc.
Feedback complicates our predictions
• Tropospheric warming will transfer more water to the air
- But the effects are uncertain
• A positive feedback loop = more water vapor … more
warming … more evaporation … more water vapor …
• A negative feedback loop = more water vapor … more
clouds … shade and cool Earth OR increase evaporation
• Minor modifications of the atmosphere can lead to major
effects on climate
© 2011 Pearson Education, Inc.
Most aerosols exert a cooling effect
• Aerosols = microscopic droplets and particles
- They have either a warming or a cooling effect
• Soot (black carbon aerosols) causes warming by
absorbing solar energy
- But most tropospheric aerosols cool the atmosphere
by reflecting the sun’s rays
• Sulfate aerosols produced by fossil fuel combustion may
slow global warming, at least in the short term
- Volcanic eruptions reduce sunlight reaching Earth’s
surface and cool the Earth
© 2011 Pearson Education, Inc.
Radiative forcing expresses change in
• Radiative forcing = the amount of change in thermal
energy that a given factor causes
- Positive forcing warms the surface
- Negative forcing cools it
Earth is experiencing
radiative forcing of 1.6
watts/m2 more than it is
emitting to space – enough
to alter the climate
© 2011 Pearson Education, Inc.
Milankovitch cycles influence climate
• Milankovitch cycles = periodic
changes in Earth’s rotation and
orbit around the sun
- Alter the way solar radiation
is distributed over Earth
• These cycles modify patterns of
atmospheric heating
- Triggering climate variation
- For example, periods of cold
glaciation and warm
interglacial times
© 2011 Pearson Education, Inc.
Solar output and ocean absorption influence
• Solar output = the sun varies in the radiation it emits
- Variation in solar energy (e.g., solar flares) has not
been great enough to change Earth’s temperature
- Radiative forcing is 0.12 watts/m2 – much less than
human causes
• Ocean absorption = the ocean holds 50 times more carbon
than the atmosphere
- Slowing global warming but not preventing it
• Warmer oceans absorb less CO2
- A positive feedback effect that accelerates warming
© 2011 Pearson Education, Inc.
Ocean circulation influences climate
• Ocean circulation = ocean water exchanges heat with
the atmosphere,
- Currents move energy from place to place
• The ocean’s thermohaline circulation system affects
regional climates
- Moving warm tropical water north, etc.
- Greenland’s melting ice sheet will affect this flow
• El Niño–Southern Oscillation (ENSO)
- Shifts atmospheric pressure, sea surface
temperature, ocean circulation in the tropical Pacific
© 2011 Pearson Education, Inc.
Direct measurements tell us about the present
• We document daily fluctuations in weather
- Precise thermometer measurements over the past 100
• Measuring of ocean and
atmospheric chemistry began
in 1958
• Precise records of historical
- Droughts, etc.
Atmospheric CO2
concentrations have increased
from 315 ppm to 389 ppm
© 2011 Pearson Education, Inc.
Proxy indicators tell us about the past
• Paleoclimate = climate of the geological past
• Gives a baseline to compare to today’s climate
• Proxy indicators = indirect evidence that serve as
substitutes for direct measurements
- Shed light on past climate
- Ice caps, ice sheets, and glaciers hold clues to Earth’s
climate history
- Trapped bubbles in ice cores provide a timescale of:
- Atmospheric composition, greenhouse gas
concentrations, temperature trends
- Snowfall, solar activity, and frequency of fires
© 2011 Pearson Education, Inc.
Ice cores from Antarctica
• Ice cores let us go back in time 800,000 years
- Reading Earth’s history across eight glacial cycles
© 2011 Pearson Education, Inc.
More proxy indicators
• Cores in sediment beds preserve pollen grains and
other plant remnants
• Tree rings indicate age, precipitation, droughts, and fire
• In arid regions, packrats carry seeds and plants to their
middens (dens)
- Plant parts can be preserved for centuries
• Researchers gather data on past ocean conditions from
coral reefs
• Scientists combine multiple records to get a global
© 2011 Pearson Education, Inc.
Models help us predict the future
• Climate models = programs
combine what is known about:
- Atmospheric and ocean
- Atmosphere–ocean
- Feedback mechanisms
Models simulate climate processes to accurately
predict climate change
© 2011 Pearson Education, Inc.
Results from three simulations
• Figure (a) shows natural climate
factors only
- Volcanoes
• Figure (b) shows only human
- Greenhouse gas emissions
• Figure (c) shows both factors
© 2011 Pearson Education, Inc.
Current and future trends and impacts
• Evidence that climate conditions have changed since
industrialization is everywhere
- Fishermen in the Maldives, ranchers in Texas,
homeowners in Florida, etc.
• Scientific evidence that climate has changed is
overwhelming and indisputable
• Intergovernmental Panel on Climate Change (IPCC)
was established in 1988
- Composed of hundreds of international scientists and
government officials
© 2011 Pearson Education, Inc.
The IPCC’s fourth assessment report (2007)
• The IPCC reports on the synthesis of scientific
information concerning climate change
- Global consensus of scientific climate research
- Summarized thousands of studies
• Documented observed trends in surface temperature,
precipitation patterns, snow and ice cover, sea levels,
storm intensity, etc.
• Predicted impacts of current and future climate change on
wildlife, ecosystems, and human societies
• Discussed strategies to pursue in response to climate
© 2011 Pearson Education, Inc.
The IPCC’s fourth assessment report (2007)
© 2011 Pearson Education, Inc.
Temperatures continue to increase
• Average surface temperatures increased 0.74 °C since
- Most of the increase occurred in the last few decades
- Extremely hot days have increased
- The 16 warmest years on record have been since 1990
© 2011 Pearson Education, Inc.
The future will be hotter
• In the next 20 years, temperatures will rise 0.4 °C
• At the end of the 21st century, temperatures will be 1.8–
4.0 °C higher than today’s
- We will have unusually hot days and heat waves
• Polar areas will have the most intense warming
• Sea surface temperatures will rise
• Hurricanes and tropical storms will increase
- In power and duration
© 2011 Pearson Education, Inc.
Temperatures will rise globally
Projected increases in surface temperature for
2090–2099 relative to 1980–1999
© 2011 Pearson Education, Inc.
Precipitation is changing, too
• Some regions are receiving more precipitation than
usual, and others are receiving less
• Droughts have become more frequent and severe
- Harming agriculture, promoting soil erosion,
reducing water supplies, and triggering fires
• Heavy rains contribute to flooding
- Killing people, destroying homes, and inflicting
billions of dollars in damage
© 2011 Pearson Education, Inc.
Projected changes in precipitation
Precipitation will increase at high latitudes and
decrease at low and middle latitudes
© 2011 Pearson Education, Inc.
Melting snow and ice
• Mountaintop glaciers are disappearing
- Glaciers on tropical mountaintops have disappeared
- The remaining 26 of 150 glaciers in Glacier National
Park will be gone by 2020 or 2030
- Reducing summertime water supplies
• Melting of Greenland’s Arctic ice sheet is accelerating
• Warmer water is melting Antarctic coastal ice shelves
- Interior snow is increasing due to more precipitation
• Melting ice exposes darker, less-reflective surfaces,
which absorb more sunlight, causing more melting
© 2011 Pearson Education, Inc.
Worldwide, glaciers are melting rapidly
• Nations are rushing to exploit underwater oil and mineral
resources made available by newly opened shipping lanes
• Permafrost (permanently frozen ground) is thawing
- Destabilizing soil, buildings, etc. and releasing methane
© 2011 Pearson Education, Inc.
Rising sea levels
• Runoff from melting glaciers and ice will cause sea
levels to rise
• As oceans warm, they expand
- Leading to beach erosion, coastal floods, and
intrusion of salt water into aquifers
© 2011 Pearson Education, Inc.
Coastal areas will flood
An earthquake caused the
2004 tsunami (tidal wave)
that killed 100 Maldives
residents and caused $470
million in damages
• Storm surge = temporary, localized rise in sea level
- Caused by the high tides and winds of storms
• Cities will be flooded
- 53% of people in the U.S. live in coastal areas
© 2011 Pearson Education, Inc.
Rising sea levels will devastate coasts
• 1 million acres of Louisiana’s wetlands are gone
- Rising sea levels eat away vegetation
- Dams upriver decrease siltation
- Pollution from the Deepwater Horizon
• Millions of people will be displaced from coastal areas
© 2011 Pearson Education, Inc.
Coral reefs are threatened
• Coral reefs are habitat for food fish
- Snorkeling and scuba diving sites for tourism
• Warmer waters contribute to coral bleaching
- Which kills corals
• Increased CO2 is acidifying the ocean
- Organisms can’t build their exoskeletons
• Oceans have already decreased by 0.1 pH unit
- Enough to kill most coral reefs
© 2011 Pearson Education, Inc.
Climate change affects organisms and
• Organisms are adapted to their environments
- They are affected when those environments change
• Global warming modifies temperature-dependent
phenomena (e.g., timing of migration, breeding)
• Animals and plants will move toward the poles or
upward in elevation
- 20–30% of species will be threatened with extinction
- Rare species will be pushed out of preserves
• Droughts, fire, and disease will decrease plant growth
- Fewer plants means more CO2 in the atmosphere
© 2011 Pearson Education, Inc.
Animals and plants have nowhere to go
• Animals and plants adopted to montane environments
will be forced uphill until there is no place to go
© 2011 Pearson Education, Inc.
Climate change affects people
• Societies are feeling the impacts of climate change
• Agriculture: shortened growing seasons, decreased
production, crops more susceptible to droughts
- Increasing hunger
• Forestry: increased fires, invasive species
- Insect and disease outbreaks
• Health: heat waves and stress can cause death
- Respiratory ailments, expansion of tropical diseases
- Disease and sanitation problems from flooding
- Drowning from storms
© 2011 Pearson Education, Inc.
Heat waves will increase
© 2011 Pearson Education, Inc.
Climate change affects economics
• Costs will outweigh benefits of climate change
• It will widen the gap between rich and poor
- Those with less wealth and technology will suffer most
• External costs of damages will be $10–350/ton of carbon
• It will cost 1–5% GDP on average globally
- Poor nations will lose more than rich ones
• The Stern Review predicts it will cost 5–20% of GDP by
- Investing 1% of GDP now could avoid these costs
© 2011 Pearson Education, Inc.
Impacts will vary regionally
• Where we live will determine how we experience the
impacts of climate change
• Temperature changes have been greatest in the Arctic
- Melting ice sheets, thinning ice, increasing storms, etc.
- Harder for people and polar bears to hunt
• U.S. temperatures will continue rising
- Plant communities will shift north and upward
- More frequent extreme weather events
• The southern U.S. will get drier, the northern wetter
- Sea levels will rise and may be worse in the East
© 2011 Pearson Education, Inc.
Impacts of climate change
The Arctic has suffered
the most so far
U.S. temperatures will continue to rise
© 2011 Pearson Education, Inc.
Impacts of climate change will vary
© 2011 Pearson Education, Inc.
The U.S. Global Change Research Program
• In 2009, scientists reported and predicted:
- Temperature increases
- Worse droughts and flooding
- Decreased crop yields
- Water shortages
- Health problems and diseases
- Higher sea levels, beach erosion, destroyed wetlands
- Drought, fire, and pests will change forests
- More grasslands and deserts, fewer forests
- Undermined Alaskan buildings and roads
© 2011 Pearson Education, Inc.
Predictions from two climate models
By 2050, Illinois will
have a climate like
By 2090, it will have a
climate like Louisiana’s
© 2011 Pearson Education, Inc.
Causes and consequences of climate
© 2011 Pearson Education, Inc.
Are we responsible for climate change?
• Scientists agree that increased greenhouse gases are
causing global warming
- Burning fossil fuels is increasing greenhouse gases
• In 2005, scientists from 11 nations issued a joint
statement urging political leaders to take action
• There is a broad and clear scientific consensus that
climate change is a pressing issue
- But many people deny what is happening
• People will admit the climate is changing
- But doubt we are the cause
© 2011 Pearson Education, Inc.
The debate over climate change is over
• Conservative think tanks and industry-sponsored
scientists cast doubt on the scientific consensus
• The news media tries to present two sides to an issue
- But the sides’ arguments are not equally supported by
• Most Americans accept that fossil fuel consumption is
changing the planet
• Al Gore’s An Inconvenient Truth helped turn the tide
- People who disliked his politics rejected his message
© 2011 Pearson Education, Inc.
• In 2009, a hacker illegally broke into a university’s
computer in the U.K.
• Private emails seemed to show questionable behavior by
a few scientists in using data
• Climate deniers accused the entire scientific
establishment of wrongdoing and conspiracy
- The story was widely told in the news
• Investigations showed no evidence of wrongdoing
- Media accounts misrepresented the email contents
• These hacked emails do not call into question the vast
array of results by thousands of scientists over decades
© 2011 Pearson Education, Inc.
Shall we pursue mitigation or adaptation?
• Most people accept that our planet is changing
- They are searching for solutions
• Mitigation = pursue actions that reduce greenhouse gas
emissions to lessen severity of future climate change
- Energy efficiency, renewable energy, protecting soil,
preventing deforestation
• Adaptation = accept that climate change is happening
- Pursue strategies to minimize its impacts on us
- Seawalls, leaving the area, coping with drought, etc.
• Both are necessary
© 2011 Pearson Education, Inc.
We need both adaptation and mitigation
• Adaptation: even if we
stopped all emissions,
warming would continue
• Mitigation: if we do nothing,
we will be overwhelmed by
climate changes
The faster we reduce our emissions,
the less we will alter the climate
© 2011 Pearson Education, Inc.
Electricity generation
A coal-fired,
power plant
• The largest source of U.S. CO2 emissions
- 70% of electricity comes from fossil fuels
- Coal causes 50% of emissions
• To reduce fossil fuel use:
- Encourage conservation and efficiency
- Switch to cleaner and renewable energy sources
© 2011 Pearson Education, Inc.
Conservation and efficiency
• We can make lifestyle choices to reduce electricity use
- Use fewer greenhouse-gas-producing appliances
- Use electricity more efficiently
• The EPA’s Energy Star Program rates appliances, lights,
windows, etc. by their energy efficiency
- Replace old appliances with efficient ones
- Use compact fluorescent lights
- Use efficient windows, ducts, insulation, heating and
cooling systems
© 2011 Pearson Education, Inc.
Sources of electricity
• We need to switch to clean energy sources
- Nuclear power, biomass energy, solar, wind, etc.
• We need to consider how we use fossil fuels
- Switching from coal to natural gas cuts emissions 50%
- Cogeneration produces fewer emissions
• Carbon capture = removes CO2 from power plant
• Carbon sequestration (storage) = storing carbon
underground where it will not seep out
- Use depleted oil and gas deposits, salt mines, etc.
- We can’t store enough CO2 to make a difference
© 2011 Pearson Education, Inc.
• 2nd largest source of U.S.
greenhouse gases
- Cars are inefficient
• Ways to help:
- More efficient cars
- Hybrid or electric cars
- Drive less and use
public transportation
- Live near your job, so
you can bike or walk
U.S. public transportation
saves 4.2 billion gallons
of gasoline and 37 million
metric tons of CO2
© 2011 Pearson Education, Inc.
Conventional cars are inefficient
© 2011 Pearson Education, Inc.
We can reduce emissions in other ways
• Agriculture: sustainable land management lets soil store
more carbon
- Reduce methane emissions from rice and cattle
- Grow renewable biofuels
• Forestry: reforest cleared land, preserve existing forests
- Sustainable forestry practices
• Waste management: treating wastewater
- Generating electricity by incinerating waste
- Recovering methane from landfills
• Individuals can recycle, compost, reduce, or reuse goods
© 2011 Pearson Education, Inc.
We need to follow multiple strategies
• There is no magic bullet for mitigating climate change
• Most reductions can be achieved using current
technology that we can use right away
• Stabilization triangle = a portfolio of strategies, each one
feasible in itself, that could stabilize CO2 emissions
- Reducing 1 billion tons of carbon per year for 50
would eliminate one of the seven “wedges”
• This approach is not enough – we need to reduce, not
only stabilize, emissions
© 2011 Pearson Education, Inc.
Strategies to stabilize CO2 emissions
15 strategies could each take care of one wedge
© 2011 Pearson Education, Inc.
• U.N. Framework Convention on Climate Change = a
plan to reduce greenhouse gas emissions to 1990 levels by
2000 through a voluntary, nation-by-nation approach
• By the late 1990s, it was clear that the voluntary approach
would not succeed
• Developing nations created a binding international treaty
requiring emission reductions
• The Kyoto Protocol = between 2008 and 2012, signatory
nations must reduce emissions of six greenhouse gases to
levels below those of 1990
© 2011 Pearson Education, Inc.
The Kyoto Protocol tried to limit emissions
• This treaty took effect in 2005
- After Russia became the 127th nation to ratify it
• The United States will not ratify the Kyoto Protocol
- It requires industrialized nations to reduce emissions
- But it does not require industrializing nations (China
and India) to reduce theirs
• Other countries resent the U.S. because it emits 20% of
the world’s greenhouse gases but won’t take action
- In 2007, one delegate said, “If for some reason you are
not willing to lead...please get out of the way.”
© 2011 Pearson Education, Inc.
The Copenhagen conference
• The conference in 2009 tried to design a successor treaty
to the Kyoto Protocol
- Nations hoped the U.S., under President Obama,
would participate in a full international agreement
• Obama would not promise more than Congress had
agreed to
• In a last-minute deal, developed nations will help
developing nations pay for mitigation and adaptation
- Nations that reduce deforestation will be rewarded
• Nothing is legally binding and no targets are set
© 2011 Pearson Education, Inc.
Will emissions cuts hurt the economy?
• The U.S. Senate feels
emissions reductions will
hurt the economy
• China and India also resist
emissions cuts
• Economic vitality does not
need higher emissions
- Germany cut emissions by 21%, the U.K. by 17%
• Industrialized nations will gain from energy transitions
- They invent, develop, and market new technologies
• The future will belong to nations willing to develop new
technologies and energy sources
© 2011 Pearson Education, Inc.
States and cities are advancing policies
• The U.S. federal government is not taking
- State and local governments are
• By 2010, 1,000 mayors signed the U.S.
Mayors Climate Protection Agreement
- To meet or beat Kyoto Protocol guidelines
• California passed the Global Warming Solutions Act
- To cut emissions 25% by 2020
• Regional Greenhouse Gas Initiative
(RGGI) in 2007
- 10 northeastern states
- Set up a cap-and-trade program
© 2011 Pearson Education, Inc.
Market mechanisms address climate change
• Permit trading programs harness the economic efficiency
of the free market to achieve policy goals
- Businesses have flexibility in how they meet the goals
• Polluters choose how to cut their emissions
- They are given financial incentives to reduce them
© 2011 Pearson Education, Inc.
Cap-and-trade emissions trading programs
• The approach of the Regional Greenhouse Gas Initiative:
- Each state decides which polluting sources participate
- Each state sets a cap on total CO2 emissions it allows
- Each emissions source gets one permit for each ton
they emit, up to the amount of the cap
- Each state lowers its cap over time
- States with too few permits must reduce emissions,
buy permits from others, or pay for carbon offsets
- Sources with too many permits may sell them
- Any source emitting more than permitted will be
© 2011 Pearson Education, Inc.
Cap-and-trade programs already exist
• Chicago Climate Exchange = the world’s first emissions
trading program for greenhouse gas reduction
- 350 corporations, institutions, etc.
- Voluntary but legally binding trading system aims for
a 6% reduction in emissions by 2010
• The European Union Emission Trading Scheme
- The world’s largest cap-and-trade program
- Governments had allocated too many permits
• Permits only work if government policies limit emissions
© 2011 Pearson Education, Inc.
Carbon taxes are another option
• Critics say cap-and-trade systems are not effective
• Carbon tax = governments charge polluters a fee for
each unit of greenhouse gases they emit
- Polluters have a financial incentive to reduce
- European nations, British Columbia, and Boulder,
Colorado have carbon taxes
• Polluters pass costs on to consumers
• Fee-and-dividend = funds from the carbon tax (fee) are
passed to taxpayers as refunds (dividends)
© 2011 Pearson Education, Inc.
Carbon offsets are popular
• Carbon offset = a voluntary payment intended to enable
another entity to reduce the greenhouse emissions that one
is unable to reduce oneself
- The payments offset one’s own emissions
• Popular among utilities, businesses, universities,
governments, and individuals
- Trying to achieve carbon-neutrality, where no net
carbon is emitted
• Carbon offsets fall short
- Needs rigorous oversight to make sure that the offset
money accomplishes what it is intended for
© 2011 Pearson Education, Inc.
You can reduce your carbon footprint
• Carbon footprint = expresses the amount of carbon we
are responsible for emitting
• People may apply many strategies to decrease their
• College students must help drive personal and societal
changes needed to mitigate climate change
• Global climate change may be the biggest challenge
facing us and our children
- With concerted action, we can avert the most severe
© 2011 Pearson Education, Inc.
The International Day of Climate Action
• On October 24, 2009, 5,200 events were held in 181
- “The most widespread day of political action in the
planet’s history”
© 2011 Pearson Education, Inc.
• Many factors influence Earth’s climate
- Human activities play a major role
• Climate change is well underway
- Further greenhouse gas emissions will cause severe
• More and more scientists are urging immediate action
• Reducing emissions and mitigating and adapting to a
changing climate is the foremost challenge for our society
© 2011 Pearson Education, Inc.
“Global warming” is defined as:
Long-term atmospheric conditions
Trends and variations in Earth’s climate
An increase in Earth’s average temperature
Atmospheric gases that absorb infrared radiation
© 2011 Pearson Education, Inc.
Which of the following greenhouse gases is of most
Carbon dioxide
Water vapor
© 2011 Pearson Education, Inc.
Which of the following is a type of proxy indicator?
Ice cores
Tree rings
Sediment cores containing pollen grains
All of these are proxy indicators
© 2011 Pearson Education, Inc.
Which of the following are major contributors of global
Burning fossil fuels and recycling
Burning fossil fuels and deforestation
Deforestation and nuclear energy
Fossil fuels and nuclear energy
© 2011 Pearson Education, Inc.
U.S. emissions of greenhouse gases have:
Gone away
© 2011 Pearson Education, Inc.
Which statement is true regarding climate change?
a) Climate is changing, but the evidence is lacking that
humans are the cause of this change.
b) There is a broad and clear scientific consensus that
climate change is a pressing issue.
c) The evidence is not yet strong enough to definitely say
that climate is changing.
d) Scientists are driven by greed to modify data about
climate change.
© 2011 Pearson Education, Inc.
What happens in a cap-and-trade program?
a) People pay higher taxes to drive larger cars.
b) Industries pay the government higher taxes, which
they pass on to consumers in higher prices.
c) Industries must buy permits for their emissions.
d) Industries can voluntarily decrease emissions.
© 2011 Pearson Education, Inc.
QUESTION: Viewpoints
Do you think cap-and-trade should be enacted in the United
States for carbon dioxide emissions?
a) Yes, because industries will have incentives to decrease
b) Yes, but only large corporations should be forced to
c) No; we are in an economic crisis and don’t need any
new taxes.
d) No; people will adapt to new conditions.
© 2011 Pearson Education, Inc.
QUESTION: Interpreting Graphs and Data
According to this model, which area will have increased
droughts and starvation?
The United States
The tip of South America
North Africa
© 2011 Pearson Education, Inc.
QUESTION: Interpreting Graphs and Data
Which statement is supported by this figure?
a) CO2 emissions have
stabilized recently.
b) CO2 emissions increased
only in Hawaii.
c) CO2 emissions have
increased drastically.
d) CO2 emissions average
320 ppm.
© 2011 Pearson Education, Inc.