Climate Control and Ozone Depletion - PowerPoint PPT Presentation

Loading...

PPT – Climate Control and Ozone Depletion PowerPoint presentation | free to view - id: 715f49-NWQ3M



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Climate Control and Ozone Depletion

Description:

Climate Control and Ozone Depletion Chapter 19 – PowerPoint PPT presentation

Number of Views:44
Avg rating:3.0/5.0
Slides: 101
Provided by: you9205
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Climate Control and Ozone Depletion


1
Climate Control and Ozone Depletion
  • Chapter 19

2
Core Case Study Studying a Volcano to Understand
Climate Change
  • June 1991 Mount Pinatubo (Philippines) exploded
  • Airborne pollutants, deaths, and damage
  • Affected climate temperature cooled Earth by 1
    degree F over a 19 month period
  • Climate predictions based on the forecasts of
    James Hansen of NASA

3
Fig. 19-1, p. 496
4
19-1 Global Warming and Global Cooling Are Not
New
  • Over the past 4.7 billion years the climate has
    been altered by
  • Volcanic emissions
  • Changes in solar input
  • Movement of the continents
  • Impacts by meteors
  • Over the past 900,000 years
  • Many fluctuations of several degrees centigrade
  • Glacial (100,000 years) and interglacial periods
    (10,000- 25, 000 years )

5
Fig. 19-2, p. 498
6
Earths Orbital Mechanics
  • Milutin Milankovitch (1879-1958), Serbian
    astrophysicist
  • First known for his bridge work, Milankovitch was
  • interned during WWI and during this time first
    began
  • to formulate his theories relating Earths
    motions
  • and long-term climate change
  • A mathematical theory of climate based on the
    seasonal and latitudinal variations of solar
    radiation received by the Earth
  • Milankovitch Theory states that as the Earth
    travels around the sun, cyclical variations in
    three elements of Earth-sun geometry combine to
    produce variations in the amount of solar energy
    that reaches Earth

7
Earths Orbital Mechanics
(1) Variations in the Earth's orbital
eccentricitythe shape of the orbit around the
sun.
(2) Changes in obliquitychanges in the angle
that Earth's axis makes with the plane of Earth's
orbit
3) Precessionthe change in the direction of the
Earth's axis of rotation, i.e., the axis of
rotation behaves like the spin axis of a top that
is winding down hence it traces a circle on the
celestial sphere over a period of time.
8
  • Milutin Milankovitch
  • Using these three orbital variations,
    Milankovitch formulated a mathematical model that
    calculated latitudinal differences in insolation
    and the corresponding surface temperature for
    600,000 years prior to the year 1800. He then
    correlated these changes with the growth and
    retreat of the Earths Ice Ages.
  • Though his first monograph on the subject was
    published in 1920, it was alternately ignored and
    refuted for about 50 years. As with many areas of
    science, theories predated that observational
    evidence. It wasnt until 1976, when a study
    published in the journal Science examined
    deep-sea sediment cores over 450,000 revealed the
    relationship.

9
Global Warming and Global Cooling Are Not New
  • Over the past 10,000 years
  • Interglacial period
  • Over the past 1,000 years
  • Temperature stable
  • Over the past 100 years
  • Temperature changes methods of determination

10
Our Climate, Lives, and Economies Depend on the
Natural Greenhouse Effect
  • Without the natural greenhouse effect
  • Cold, uninhabitable earth

11
Human Activities Emit Large Quantities of
Greenhouses Gases
  • Since the Industrial Revolution
  • CO2, CH4, and N2O emissions higher
  • Main sources agriculture, deforestation, and
    burning of fossil fuels
  • Correlation of rising CO2 and CH4 with rising
    global temperatures
  • Countries with the largest CO2 emissions in 2007
  • U.S (25), China (5), European union (27
    countries), Indonesia, Russia, Japan, and India.

12
Table 21-1Page 464
Table 21-1 Major Greenhouse Gases from Human
Activities
Greenhouse Gas Carbon dioxide (CO2) Methane
(CH4) Nitrous oxide (N2O) Chlorofluorocarbon
s (CFCs) Hydrochloro- fluorocarbons
(HCFCs) Hydrofluorocarbons (HFCs) Halons Carbo
n tetrachloride
Average Time in the Troposphere 100120
years 1218 years 114120 years 1120
years (65110 years in stratosphere) 9390 15
390 65 42
Human Sources Fossil fuel burning, especially
coal (7075), deforestation, and plant
burning Rice paddies, guts of cattle and
termites, landfills, coal production, coal seams,
and natural gas leaks from oil and gas production
and pipelines Fossil fuel burning, fertilizers,
livestock wastes, and nylon production Air
conditioners, refrigerators, plastic foams Air
conditioners, refrigerators, plastic foams Air
conditioners, refrigerators, plastic foams Fire
extinguishers Cleaning solvent
Relative Warming Potential (compared to
CO2) 1 23 296 9008,300 4702,000 13
012,700 5,500 1,400
Water Vapor None
13
The Causes of Global Climate Change
Sulfur Hexafluoride-, SF6 is the most potent
greenhouse gas
14
(No Transcript)
15
(No Transcript)
16
Fig. 19-4, p. 500
17
Human Activities Emit Large Quantities of
Greenhouses Gases
  • Per capita emissions of CO2
  • Scientific and economic studies
  • 2007 Field and Marland
  • Tipping point
  • 2008 Aufhammer and Carson
  • Chinas CO2 emission growth may be underestimated
  • Ice core analysis of air pollutants

18
Fig. 19-3, p. 498
19
The Atmosphere Is Warming Mostly Because of Human
Activities (1)
  • Intergovernmental Panel on Climate Change (IPCC)
  • 9099 likely that lower atmosphere is warming
  • 19062005 Ave. temp increased about 0.74C
  • 19702005 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 1020 cm

20
The Atmosphere Is Warming Mostly Because of Human
Activities
  • Al Gore and the IPCC Nobel Peace Prize
  • What natural and human-influenced factors could
    have an effect on temperature changes?
  • Amplify
  • Dampen

21
Five Warmest Years on Record
  • 2005
  • 1998
  • 2002
  • 2003
  • 2006
  • Since 1980, the Earth has experienced
  • 19 of its 20 hottest years on record

22
What Is the Scientific Consensus about Future
Temperature Change?
  • Mathematical models used for predictions
  • Global warming rapid rate
  • Human factors are the major cause of temperature
    rise since 1950
  • Human factors will become a greater risk factor

23
Is a Hotter Sun the Culprit?
  • Since 1975
  • Troposphere has warmed
  • Stratosphere has cooled
  • This is not what a hotter sun would do

24
Can the Oceans Save Us?
  • Solubility of CO2 in ocean water
  • Warmer oceans
  • CO2 levels increasing acidity
  • Effect on atmospheric levels of CO2
  • Effect on coral reefs
  • Antarcticas Southern Ocean and the North
    Atlantic Ocean
  • Decrease in CO2 uptake
  • Significance on global CO2 levels

25
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
  • Effect of jet entrails on climate temperature

26
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

27
19-2 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

28
(No Transcript)
29
Melting of Alaskas Muir Glacier in the popular
Glacier Bay National Park and Preserve between
1948 and 2004.
30
(No Transcript)
31
(No Transcript)
32
Severe Drought Is Increasing The Browning of
the Earth
  • Accelerate global warming, lead to more drought,
    hurricanes, prolonged heat waves and
    desertification.
  • Biodiversity will decrease
  • NPP will decrease
  • Dry climate ecosystems will increase

33
Ice and Snow Are Melting (1)
  • Why will global warming be worse in the polar
    regions?
  • Important climate role of floating sea ice
  • Mountain glaciers affected by
  • Average snowfall
  • Average warm temperatures

34
Fig. 19-6, p. 501
35
Albedo Effect
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
Albedo, or reflectivity
Fig. 21-17 p. 480
40
(No Transcript)
41
Ice and Snow Are Melting
  • Europes Alps
  • Glaciers are disappearing
  • South America
  • Glaciers are disappearing
  • Greenland
  • Warmer temperatures

42
Science Focus Melting Ice in Greenland
  • Largest island 80 composed of glaciers
  • 10 of the worlds fresh water
  • 19962007 net loss of ice doubled
  • Effect on sea level if melting continues

43
Fig. 19-C, p. 508
44
Sea Levels Are Rising (1)
  • Expansion of warm water
  • Melting of land-based ice
  • What about Greenland?

45
Sea Levels Are Rising (2)
  • 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

46
Thermal expansion
  • Thermal expansionWhile thermal expansion is a
    less obvious process than melting ice (mainly
    because you can't see it happening) the IPCC
    projects that thermal expansion will be the
  • main component of
  • expected sea-level rises
  • over the 21st century.

47
ALABAMA
GEORGIA
Jacksonville
Tallahassee
Pensacola
Atlantic Ocean
Orlando
Gulf of Mexico
Tampa
FLORIDA
Fort Meyers
Naples
Miami
Key West
Fig. 19-8, p. 509
48
Fig. 19-9, p. 510
49
Effects of Global Climate Change
Melting Ice and Rising Sea Levels
50
Fig. 19-7, p. 507
51
Permafrost Is Likely to Melt Another Dangerous
Scenario
  • Carbon present as CH4 in permafrost soils and
    lake bottoms
  • 2004 Arctic Climate Impact Assessment
  • 1020 of the permafrost might melt this century
  • Effect on global warming

52
Fig. 19-10, p. 510
53
Melting permafrost means an increase in soil
bacterial activity and an increase in CH4
emissions.
54
Ocean Currents Are Changing but the Threat Is
Unknown
  • Melting glaciers, particularly in Greenland
  • Increased rain in the North Atlantic
  • Not thought to be an immediate problem on the
    ocean currents

55
Changing Ocean Currents
Global warming could alter ocean currents and
cause both excessive warming and severe cooling.
56
Extreme Weather Will Increase in Some Areas
  • Heat waves and droughts in some areas
  • Prolonged rains and flooding in other areas
  • Will storms get worse?
  • More studies needed
  • Hurricanes Katrina and Rita

57
Global Warming Is a Major Threat to Biodiversity
(1)
  • Most susceptible ecosystems
  • Coral reefs
  • Polar seas
  • Coastal wetland
  • High-elevation mountaintops
  • Alpine and arctic tundra

58
Changes in average temperatures of ocean water,
relative to the coral bleaching threshold, past
and projected, 18602100.
Fig. 19-11, p. 512
59
Global Warming Is a Major Threat to Biodiversity
  • What about
  • Migratory animals
  • Forests
  • Which organisms could increase with global
    warming? Significance?
  • Insects
  • Fungi
  • Microbes

60
Changes in Biodiversity
Biomes
Shift of Alpine biomes up mountains and further
North/South
Die-offs
  • Coral bleaching die-offs of up to 50 in the
    Indian Ocean

Extinctions
  • Golden Toads, Harlequin Frogs, ...

Life Cycles
Gothic marmots emerge from hibernation about a
month earlier than 30 years ago
  • The average weight of adult female polar bears
    has decreased by more than 20 over the last 25
    years

Physiology
  • Multiple areas affected

Migration
61
Fig. 19-12, p. 512
62
Effects of Global Climate Change Effects on
Human Health
63
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

64
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

65
Positive Feedback
66
Positive Feedback
  • Oceans currents and CO2 levels
  • Cold deep resurface and emit CO2
  • Permafrost melting
  • CO2 and methane released by decomposition
  • Arctic ice melting
  • Less reflection of sunlight water and land heat
    up
  • Desertification
  • Soil dries out and releases CO2

67
19-3 Dealing with Climate Change Is Difficult
  • Global problem
  • Long-lasting effects
  • Long-term political problem
  • Harmful and beneficial impacts of climate change
    unevenly spread
  • Many proposed actions disrupt economies and
    lifestyles

68
SOLUTIONS
Global Warming
Cleanup
Prevention
Cut fossil fuel use (especially coal)
Remove CO2 from smokestack and vehicle emissions
Shift from coal to natural gas
Store (sequester) CO2 by planting trees
Improve energy efficiency
Sequester CO2 deep underground (with no leaks
allowed)
Shift to renewable energy resources
Transfer energy efficiency and renewable energy
technologies to developing countries
Sequester CO2 in soil by using no-till
cultivation and taking cropland out of production
Reduce deforestation
Sequester CO2 in the deep ocean (with no leaks
allowed)
Use more sustainable agriculture and forestry
Repair leaky natural gas pipelines and facilities
Limit urban sprawl
Use animal feeds that reduce CH4 emissions from
cows (belching)
Reduce poverty
Slow population growth
Fig. 19-13, p. 515
69
What Are Our Options?
  • Two approaches
  • Drastically reduce the amount of greenhouse gas
    emissions
  • Devise strategies to reduce the harmful effects
    of global warming
  • Will we reach a political tipping point before we
    reach irreversible climate change tipping points?

70
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

71
Avoiding Catastrophe We Can Reduce the Threat of
Climate Change
  • Socolow and Pacala
  • Climate stabilization wedges
  • Keep CO2 emissions to 2007 levels by 2057
  • Brown need to do more
  • Cut CO2 emissions by 80 by 2020
  • 2008 book Plan B 3.0 Mobilizing to Save
    Civilization

72
Fig. 19-14, p. 515
73
Avoiding Catastrophe We Can Reduce the Threat of
Climate Change (3)
  • Output solutions
  • Massive global tree planting how many?
  • Wangari Maathai
  • Great Wall of Trees China and Africa
  • Plant fast-growing perennials on degraded land
  • Capturing and storing CO2

74
Case Study Is Capturing and Storing CO2 the
Answer? (1)
  • Carbon capture and storage (CCS) next slide
  • Several problems with this approach
  • Power plants using CCS
  • More expensive to build
  • None exist
  • Unproven technology
  • Large inputs of energy to work
  • Increasing CO2 emissions

75
Output methods for removing carbon dioxide from
the atmosphere
Fig. 19-15, p. 516
76
Case Study Is Capturing and Storing CO2 the
Answer?
  • Problems with carbon capture and storage cont
  • Promotes the continued use of coal (worlds
    dirtiest fuel)
  • Effect of government subsidies and tax breaks
  • Stored CO2 would have to remain sealed forever
    no leaking

77
Should We Use Geo-Engineering Schemes to Help
Slow Climate Change?
  • CCS- Carbon Capture and Stsorage
  • Injection of sulfate particles into the
    stratosphere
  • Would it have a cooling effect?
  • Would it accelerate O3 depletion?

78
Should We Use Geo-Engineering Schemes to Help
Slow Climate Change?
  • Remove HCl from seawater
  • Effects on ecology?
  • Pump up nutrient-rich deep ocean water and cause
    algal blooms
  • Re-ice the Arctic
  • If any of these fixes fail, what about a rebound
    effect?

79
Governments Can Help Reduce the Threat of Climate
Change
  • Strictly regulate CO2 and CH4 as pollutants
  • Cap-and-trade approach
  • Increase subsidies to encourage use of
    energy-efficient technology
  • Technology transfer

80
Governments Can Enter into International Climate
Negotiations The Kyoto Protocol
  • 1997 Treaty to slow climate change
  • 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 reduce emissions of CO2, CH4, and N2O by 2012
    to levels of 1990
  • Trading greenhouse gas emissions among countries
  • Not signed by the U.S.
  • U.S. did not sign because developing countries
    such as China, India and Brazil were excluded.

81
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

82
Some Companies and Schools Are Reducing Their
Carbon Footprints
  • Major global companies reducing greenhouse gas
    emissions
  • Alcoa
  • DuPont
  • IBM
  • Toyota
  • GE
  • Wal-Mart
  • Fluorescent light bulbs
  • Auxiliary power units on truck fleets

83
Fig. 19-16, p. 522
84
19-4 Our Use of Certain Chemicals
Threatens the Ozone Layer
  • Ozone Thinning
  • Seasonal depletion in the stratosphere
  • Antarctica and Arctic
  • Antarctic Spring(October)
  • 1930 Midgely
  • Discovered the first CFC
  • 1984 Rowland and Molina
  • CFCs were depleting O3
  • Other ozone-depleting chemicals

85
Ozone Depletion in the Stratosphere
  • The Causes of Ozone Depletion
  • Main problem CFCs (chlorofluorocarbons)
  • Other chemicals
  • Halons
  • Methyl bromide
  • Methyl chloroform (trichloroethylene)
  • Carbon tetrachloride
  • Nitrous oxide

86
Science Focus Rowland and MolineA 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
  • 1995 Nobel Prize in chemistry

87
Chlorofluorocarbons or CFCs
  • First produced by General Motors Corporation in
    1928, CFCs were created as a replacement to the
    toxic refrigerant ammonia
  • CFCs have also been used as a propellant in spray
    cans, cleaner for electronics, sterilant for
    hospital equipment, and to produce the bubbles in
    Styrofoam

88
Global average total ozone values in the
stratosphere at a certain latitude, 19792005
Fig. 19-18, p. 523
89
Massive ozone thinning over Antarctica in 2007
Fig. 19-19, p. 524
90
Sun
Ultraviolet light hits a chlorofluorocarbon (CFC)
molecule, such as CFCl3, breaking off a chlorine
atom and leaving CFCl2.
Summary of Reactions CFCl3 UV ? Cl CFCl2
Cl O3 ? ClO O2
Repeated many times
UV radiation
ClO O ? Cl O2
Cl
Cl
Cl
C
C
F
Cl
Cl
Cl
F
Once free, the chlorine atom is off to attack
another ozone molecule and begin the cycle again.
Cl
O
O
O
O
O
Ozone
The chlorine atom attacks an ozone (O3)
molecule, pulling an oxygen atom off it and
leaving an oxygen molecule (O2).
O
A free oxygen atom pulls the oxygen atom off the
chlorine monoxide molecule to form O2.

O
O
O
O
Cl
O
O
O
O
Cl
O
The chlorine atom and the oxygen atom join to
form a chlorine monoxide molecule (ClO).
O
Fig. 19-D, p. 525
91
  • A single chlorine atom removes about 100,000
    ozone molecules before it is taken out of
    operation by other substances

92
Terpenes
  • Terpenes are a class of hydrocarbons produced
    primarily by conifers.
  • A viable substitute for CFCs

93
Why Should We Worry about Ozone Depletion?
  • Damaging UV-A and UV-B radiation
  • Increase eye cataracts and skin cancer
  • Impair or destroy phytoplankton
  • Significance?

94
Stepped Art
Fig. 19-20, p. 524
95
Science Focus Skin Cancer
  • Squamous cell carcinoma
  • Basal cell carcinoma
  • Melanoma
  • Effect of UV-B radiation
  • How safe are tanning salons?

96
Stepped Art
Fig. 19-E, p. 526
97
Cataracts
www.snec.com.sg/clinical_services/ cataract.asp
98
Fig. 19-F, p. 527
99
We Can Reverse Stratospheric Ozone Depletion
  • Stop producing all ozone-depleting chemicals
  • 60100 years of recovery of the O3 layer
  • 1987 Montreal Protocol
  • (1987) stipulated a phase out of CFCs, halons,
    CCl4, CH3CCl3 by 2000 in participating
    countries.
  • 1990 London Protocol
  • a total phase out of CFCs absolutely necessary
    by 2000.
  • 1992 Copenhagen Protocol
  • (1992) MDCs agree to stop production by 1996
    (U.S. included this in the 1990 CAA) and to
    financially assist the phase out in LDCs by
    2010.

100
We Can Reverse Stratospheric Ozone Depletion
  • Substitutes for CFCs are available
  • More are being developed
  • HCFC-22
  • Substitute chemical
  • May still be causing ozone depletion
About PowerShow.com