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Climate Control and
Ozone Depletion
Chapter 19
An Enormous Cloud of Air Pollutants and
Ash from Iceland volcano (April 2010)
This dust cloud closed
Airports in Europe for
almost one week.
Coal Power Plant emitting green house gas
19-1 How Might the Earth’s Temperature
and Climate Change in the Future?
 Concept 19-1 The overwhelming scientific
consensus is that the earth’s atmosphere is
warming rapidly, mostly because of human
activities, and that this will lead to significant
climate change during this century.
How Do We Know What Temperatures Were
in the Past?
 Scientists analyze tiny
air bubbles trapped in
ice cores learn about
past:
• troposphere
composition.
• temperature trends.
• greenhouse gas
concentrations.
• solar, snowfall, and
forest fire activity.
Estimated Changes in the Average
Global Temperature of the Atmosphere
Fig19-2
Carbon Dioxide at highest levels
 In 2005, an ice core
showed that CO2
levels in the
troposphere are the
highest they have
been in 650,000
years.
The Natural Greenhouse Effect
 Four major factors shape the earth’s climate:
• The sun.
• Greenhouse effect that warms the earth’s lower
troposphere and surface because of the presence of
greenhouse gases.
• Oceans store CO2 and heat, evaporate and receive
water, move stored heat to other parts of the world.
• Natural cooling process through water vapor in the
troposphere (heat rises).
Atmospheric Levels of CO2 and CH4,
Global Temperatures, and Sea Levels
Fig 19-4
Keeling Curve
IPCC greenhouse gases by source
Carbon Dioxide Trends (IPCC)
Animation: Greenhouse effect
The Atmosphere Is Warming Mostly
Because of Human Activities
 Intergovernmental Panel on Climate Change (IPCC)
• 90–99% likely that lower atmosphere is warming
• 1906–2005: Ave. temp increased about 0.74˚C
• 1970–2005: Annual greenhouse emissions up 70%
• Past 50 years: Arctic temp rising almost twice as fast as the rest
of the earth
• Melting of glaciers and floating sea ice
• Prolonged droughts: increasing
• Last 100 years: sea levels rose 10–20 cm
• Warmer temperatures in Alaska, Russia, and the Arctic are
melting permafrost releasing more CO2 and CH4 into the
troposphere.
Melting of Alaska’s Muir Glacier
between 1948 and 2004
The Big Melt: Some of the Floating Sea
Ice in the Arctic Sea
The Scientific Consensus about Future
Climate Change
 There is strong evidence that human activities
will play an important role in changing the
earth’s climate during this century.
• Coupled General Circulation Models (CGCMs)
couple, or combine, the effects of the atmosphere
and the oceans on climate.
Sun
Troposphere
Cooling
from
increase
Aerosols GreenhouseWarming
gases
from
decrease
CO2
removal
by plants
and soil
organisms
CO2 emissions
from land
clearing, fires,
and decay
Heat and
CO2
removal
Heat and
CO2
emissions
Ice and snow cover
Shallow ocean
Land and soil biota
Natural and human
emissions
Long-term
storage
Deep ocean
Fig. 19-A, p. 502
CGC Models sources
NASA
IPCC Climate Change Model
Comparison of Measured Temperature
from 1860–2007 and Projected Changes
Fig 19-b
Intergovernmental Panel on Climate Change (IPCC)
Fourth Assessment Report 2007
Warming of the climate system is unequivocal, as is
now evident from observations of increases in global
average air and ocean temperatures, widespread
Melting of snow and ice and rising global average
sea level
(Figure SPM.1). {1.1}
Most of the observed increase in global average
Temperatures since the mid-20th century is very
likely (p = .90) due to the observed increase in
anthropogenic GHG concentrations.
(Figure SPM.4). {2.4}
Click for IPCC web page
IPCC Treatment of Uncertainty
Where uncertainty is assessed more quantitatively using
expert judgment of the correctness of underlying data,
models or analyses, then the following scale of confidence
levels is used to express the assessed chance of a finding
being correct: very high confidence at least 9 out of 10;
high confidence about 8 out of 10; medium confidence
about 5 out of 10.
Where uncertainty in specific outcomes is assessed using
expert judgment and statistical analysis of a body of evidence
(e.g. observations or model results), then the following
likelihood ranges are used to express the assessed probability
of occurrence: virtually certain >99%; extremely likely >95%;
very likely >90%; likely >66%;.
IPCC Emissions and Equilibrium Temperatures
IPCC Temperature projections
Is a Hotter Sun the Culprit?
 Since 1975
• Troposphere has warmed
• Stratosphere has cooled
 This is not what a hotter sun would do
Changing Ocean Currents
 Global warming could alter ocean currents and
cause both excessive warming and severe cooling.
Ocean Acidification
Click for NRDC Acid Test
Click for Ocean Acidification Network
FACTORS AFFECTING THE EARTH’S
TEMPERATURE
 Some factors can amplify (positive feedback)
and some can dampen (negative feedback)
projected global warming.
 There is uncertainty about how much CO2 and
heat the oceans can remove from the
troposphere and how long the heat and CO2
might remain there.
There Is Uncertainty about the Effects of
Cloud Cover on Global Warming
 Warmer temperatures create more clouds
• Thick, light-colored low altitude clouds: decrease
surface temperature
• Thin, cirrus clouds at high altitudes: increase
surface temperature
Outdoor Air Pollution Can Temporarily
Slow Global Warming
 Aerosol and soot pollutants
• Will not enhance or counteract projected global
warming
• Fall back to the earth or are washed out of the
lower atmosphere
• Reduction: especially in developed countries
DEALING WITH GLOBAL WARMING
 Climate change is such a difficult problem to deal
with because:
•
•
•
•
The problem is global.
The effects will last a long time.
The problem is a long-term political issue.
The harmful and beneficial impacts of climate
change are not spread evenly.
• Many actions that might reduce the threat are
controversial because they can impact economies
and lifestyles.
19-2 What Are Some Possible Effects of a
Warmer Atmosphere?
 Concept 19-2 The projected rapid change in
the atmosphere's temperature during this
century is very likely to increase drought and
flooding, shift areas where food can be grown,
raise sea levels, result in intense heat waves,
and cause the premature extinction of many
species.
IPCC Projected Regional Impacts
IPCC Impacts
Very likely = 90% probable
Enhanced Global Warming Could Have
Severe Consequences
 Tipping point and irreversible climate change
 Worst-case scenarios
•
•
•
•
Ecosystems collapsing
Low-lying cities flooded
Wildfires in forests
Prolonged droughts: grasslands become dust
bowls
• More destructive storms
• Glaciers shrinking; rivers drying up
Projected Effects of Global Warming and
the Resulting Changes in Global Climate
Fig 19-7
Severe Drought Is Increasing:
The Browning of the Earth
 Accelerate global warming, lead to more drought
 Biodiversity will decrease
 Net Primary Productivity (NPP) will decrease
 Dry climate ecosystems will increase
Ice and Snow Are Melting
 Europe’s Alps
• Glaciers are disappearing
 South America
• Glaciers are disappearing
 Greenland
• Warmer temperatures
Areas of Glacial Ice Melting in Greenland
during Summer 1982–2007 Increased
Fig 19-c
Sea Levels Are Rising
 Projected irreversible effect
• Degradation and loss of 1/3 of coastal estuaries,
wetlands, and coral reefs
• Disruption of coastal fisheries
• Flooding of
• Low-lying barrier islands and coastal areas
• Agricultural lowlands and deltas
• Contamination of freshwater aquifers
• Submergence of low-lying islands in the Pacific
and Indian Oceans and the Caribbean
Areas of Florida, U.S., to Flood If Average
Sea Level Rises by One Meter
Fig19-8
Low-Lying Island Nation: Maldives in
the Indian Ocean
Permafrost Is Likely to Melt: Another
Dangerous Scenario
 Carbon present as CH4 in permafrost soils and
lake bottoms
 2004: Arctic Climate Impact Assessment
• 10–20% of the permafrost might melt this century
 Effect on global warming – ice reflects heat, land
absorbs heat.
Projected Decline in Arctic Tundra in
Portions of Russia from 2004 to 2100
Fig 19-10
Global Warming Is a Major Threat to
Biodiversity
 Most susceptible ecosystems
•
•
•
•
•
Coral reefs
Polar seas
Coastal wetland
High-elevation mountaintops
Alpine and arctic tundra
Effects on Biodiversity: Winners and Losers
 Possible effects of
global warming on
the geographic range
of beech trees based
on ecological
evidence and
computer models.
Changes in Average Ocean Temperatures,
Relative to Coral Bleaching Threshold
Fig 19-11
Exploding Populations of Mountain Pine
Beetles in British Columbia, Canada
Climate Change Will Shift Areas Where
Crops Can Be Grown
 Regions of farming may shift
• Decrease in tropical and subtropical areas
• Increase in northern latitudes
• Less productivity; soil not as fertile
 Genetically engineered crops more tolerant to
drought
Climate Change Will Threaten the Health
of Many People
 Deaths from heat waves will increase
 Deaths from cold weather will decrease
 Higher temperatures can cause
• Increased flooding
• Increase in some forms of air pollution, more O3
• More insects, microbes, toxic molds, and fungi
19-3 What Can We Do to Slow Climate
Change? (1)
 Concept 19-3A To slow the rate of global
warming and climate change, we can increase
energy efficiency, sharply reduce greenhouse
gas emissions, rely more on renewable energy
resources, and slow population growth.
DEALING WITH GLOBAL WARMING
 Climate change is such a difficult problem to deal
with because:
•
•
•
•
The problem is global.
The effects will last a long time.
The problem is a long-term political issue.
The harmful and beneficial impacts of climate
change are not spread evenly.
• Many actions that might reduce the threat are
controversial because they can impact economies
and lifestyles.
19-3 What Can We Do to Slow Climate
Change? (2)
 Concept 19-3B Governments can subsidize
energy efficiency and renewable energy use, tax
greenhouse gas emissions, set up cap-andtrade emission reduction systems, and help to
slow population growth.
DEALING WITH GLOBAL WARMING
 Two ways to deal with global warming:
• Mitigation that reduces greenhouse gas emissions.
• Adaptation, where we recognize that some warming
is unavoidable and devise strategies to reduce its
harmful effects.
DEALING WITH GLOBAL WARMING
 Governments can tax greenhouse gas
emissions and energy use, increase subsidies
and tax breaks for saving energy, and decrease
subsidies and tax breaks for fossil fuels.
 A cash program to slow and adapt to global
warming now is very likely to cost less than
waiting and having to deal with its harmful
effects later.
Avoiding Catastrophe: We Can Reduce
the Threat of Climate Change
 Input or prevention strategies
 Improve energy efficiency to reduce fossil fuel
use
 Stop cutting down tropical forests
 Output strategy
• Capture and store CO2
IPCC Climate Change Model
SOLUTIONS
Global Warming
Prevention
Cleanup
Cut fossil fuel use
(especially coal)
Remove CO2 from
smokestack and vehicle
emissions
Store (sequester) CO2 by
planting trees
Sequester CO2 deep
underground (with no leaks
allowed)
Sequester CO2 in soil by
using no-till cultivation and
taking cropland out of
production
Sequester CO2 in the deep
ocean (with no leaks
allowed)
Repair leaky natural gas
pipelines and facilities
Use animal feeds that
reduce CH4 emissions from
cows (belching)
Shift from coal to natural gas
Improve energy efficiency
Shift to renewable energy
resources
Transfer energy efficiency
and renewable energy
technologies to
developing countries
Reduce deforestation
Use more sustainable
agriculture and forestry
Limit urban sprawl
Reduce poverty
Slow population growth
Fig. 19-13, p. 515
International Climate Negotiations:
The Kyoto Protocol
– Treaty on global warming which first phase went into
effect January, 2005 with 189 countries participating.
– It requires 38 participating developed countries to cut
their emissions of CO2, CH4, and N2O to 5.2% below
their 1990 levels by 2012.
– Developing countries were excluded.
• The U.S. did not sign, but California and Maine
are participating.
• U.S. did not sign because developing countries
such as China, India and Brazil were excluded.
Fifteen Ways to Cut CO2 Emissions
Stepped Art
Fig. 19-14, p. 515
Some Output Methods for Removing CO2
from the Atmosphere and Storing It
Fig19-15
Case Study: Is Capturing and Storing
CO2 the Answer?
 Problems with carbon capture and storage
cont…
• Promotes the continued use of coal (world’s
dirtiest fuel)
• Effect of government subsidies and tax breaks
• Stored CO2 would have to remain sealed forever:
no leaking. This is book’s opinion. Flint does not
agree
Some Governments Are Leading the Way
 Costa Rica: goal to be carbon neutral by 2030
 Norway: aims to be carbon neutral by 2050
 China and India must change energy habits
 U.S. cities and states taking initiatives to reduce
carbon emissions
What Can You Do? Reducing CO2
Emissions
Fig 19-16
We Can Prepare for the Harmful Effects
of Climate Change?
 Genetically engineer crops more tolerant to
drought
 Stockpile 1–5 years of key foods
 Waste less water
 Connect wildlife reserves with corridors
Ways to Prepare for the Possible LongTerm Harmful Effects of Climate Change
Fig19-17
19-4 How Have We Depleted O3 in the
Stratosphere and What Can We Do?
 Concept 19-4A Widespread use of certain
chemicals has reduced ozone levels in the
stratosphere, which allows for more harmful
ultraviolet radiation to reach the earth’s surface.
 Concept 19-4B To reverse ozone depletion,
we must stop producing ozone-depleting
chemicals and adhere to the international
treaties that ban such chemicals.
Mean Total Ozone Level
(Dobson units)
300
290
280
270
260
1970
1980
1990
2000
2010
Year
Fig. 19-18, p. 523
Natural Capital Degradation: Massive
Ozone Thinning over Antarctica in 2007
Fig 19-19
Science Focus: Rowland and Moline—A
Scientific Story of Courage and Persistence
 Research
• CFCs are persistent in the atmosphere
• Rise into the stratosphere over 11-20 years
• Break down under high-energy UV radiation
• Halogens produced accelerate the breakdown of
O3 to O2
• Each CFC molecule can last 65-385 years
 1988: Dupont stopped producing CFCs
Summary of CFCs and Other ChlorineContaining Compounds that Destroy Ozone
Fig19-d
Natural Capital Degradation: Effects of
Ozone Depletion
Fig 19-20
Structure of the Human Skin and the
Relationship between UV and Skin Cancer
Fig 19-e
This long-wavelength (low-energy) form of UV
radiation causes aging of the skin, tanning,
and sometimes sunburn. It penetrates deeply
and may contribute to skin cancer.
Ultraviolet A
This shorter-wavelength (high-energy) form of UV
radiation causes sunburn, premature aging, and
wrinkling. It is largely responsible for basal and
squamous cell carcinomas and plays a role in
malignant melanoma.
Ultraviolet B
Hair
Thin layer of dead cells
Squamous cells
Epidermis
Basal layer
Sweat gland
Melanocyte cells
Dermis
Blood vessels
Basal cell
Squamous Cell Carcinoma
Basal Cell Carcinoma
Melanoma
Stepped Art
Fig. 19-E, p. 526
Natural Capital Degradation
Effects of Ozone Depletion
Human Health
• Worse sunburn
• More eye cataracts
• More skin cancers
• Immune system suppression
Food and Forests
• Reduced yields for some crops
• Reduced seafood supplies from reduced phytoplankton
• Decreased forest productivity for UV-sensitive tree species
Wildlife
• Increased eye cataracts in some species
• Decreased population of aquatic species sensitive to UV radiation
• Reduced population of surface phytoplankton
• Disrupted aquatic food webs from reduced phytoplankton
Air Pollution and Materials
• Increased acid deposition
• Increased photochemical smog
• Degradation of outdoor paints and plastics
Fig 19-20
Global Warming
• Accelerated warming because of decreased ocean uptake of CO2 from
atmosphere by phytoplankton and CFCs acting as greenhouse gases
What Can You Do? Reducing Exposure
to UV Radiation
Fig 19-f
We Can Reverse Stratospheric
Ozone Depletion
 Stop producing all ozone-depleting chemicals
 60–100 years of recovery of the O3 layer
 1987: Montreal Protocol
 1992: Copenhagen Protocol
 Ozone protocols: prevention is the key
Animation: How CFCs destroy ozone