Welcome to 4 th Quarter Chapter 13 Global Atmosphere.
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Transcript of Welcome to 4 th Quarter Chapter 13 Global Atmosphere.
Announcements
• Grades
• Hours? 1st half, 4th quarter hours due April 16th
• TV - Environmental Documentaries ONLY!
• Science Nights and Seminar are good!
• T-SHIRT $$$$, please!!
Science Nights• March 29th – Westwood View
• April 10th - T.A. Edison (KCK)
• April 12th – Fiske (KCK)
• April 21st - Earth Fair @ SME
• April 28th - - SMSD R&D Forum
Chapter 13 Notebook1. Concept Review 20
2. Comparison Chart (notes) 15
3. Carbon Footprint 10
4. Global Warming Survival Guide 15
5. Video – The Signs and the Science 20
TOTAL 80
Global Atm. Comparison ChartCompare Climate Change to Ozone
depletionFor each, notes on the following..1. What gases are involved?2. How does the effect work?3. What are the possible consequences?4. How do we fix it?5. How are we doing?
Ozone depletion – global warming
• CFCs, Freon, chlorine
• CFCs move to the stratosphere and release chlorine atoms
• The chlorine atoms destroy ozone molecules
• Catalytic, 100,000 times per chlorine
• CO2, Methane, water vapor, nitrous oxides
• Sunlight warms the earth and bounces off as infrared.
• These gases trap infrared.
• Greenhouse effect is good, just to much of a good thing.
Consequences
• More UV gets through• Skin cancer, cataracts• Amphibian populations• Phytoplankton• Crop yields
• Disruption of weather• More droughts/floods• Crop yields• Ecosystem destruction,
(especially polar)• Sea level rise• Tropical diseases
Repair
• Stop production of CFCs• Wait 50 years
• Reduce carbon emissions from fossil fuels
• Sequester carbon• Cap and trade
Progress
• Montreal• But the CFCs are still on
their way. 50 year problem
• Kyoto• Not much progress
because of economic fears.
Ozone Depletion• Ozone is a pollutant at ground level but a
U.V. filter in the stratosphere.
• Ozone is formed in the stratosphere when high-energy ultraviolet radiation splits oxygen molecules.
• Ozone absorbs UVb. (biologically active)– UVa is harmless, UVc is deadly
Problem:• In the 1930s, the invention of CFCs allowed for
cheap refrigeration, and later, air conditioning.• Other uses added over the years• In 1970s, it was discovered that CFCs were
lowering the average concentration of Ozone in the stratosphere.– CFCs take 10-20 years to make it into the
stratosphere.• Can react with ozone for up to 120 years.
Sources of CFCs• Aerosols (spray cans)
• Foams (Styrofoam)
• Solvents (carbon tetra chloride)
• Air conditioning and refrigeration.
We no longer produce many CFCs
• CFC production has been phased out.
• Montreal Protocol in the name of the international agreement.
• The CFCs of the 80s are still there, as is the hole.
• (and the CFCs of the 90s are still on their way)
The ozone hole• Ozone depletion occurs most at the poles
where the “hole” forms
• Extends to the upper latitudes around the poles as it breaks up in the spring.
Mechanism of the Problem• In the stratosphere, UV radiation breaks
down CFC molecules, releasing atomic chlorine. A free Chlorine atom reacts with an ozone molecule, converting it from O3 to O2.
• One chlorine might destroy 100,000 ozone molecules
Ultraviolet light hits a chlorofluorocarbon (CFC) molecule, such as CFCl3, breakingoff a chlorine atom and leaving CFCl2.
UV radiation
Sun
Once free, the chlorine atom is off to attack another ozone moleculeand begin the cycle again.
A free oxygen atom pulls the oxygen atom off the chlorine monoxide molecule to form O2.
The chlorine atom and the oxygen atom join to form a chlorine monoxide molecule (ClO).
The chlorine atom attacksan ozone (O3) molecule, pulling an oxygen atom off it and leaving an oxygen molecule (O2).
Cl
Cl
ClC
F
Cl
Cl
OO
Cl
OO
O
Cl
O
OO
ClO
O
Summary of ReactionsCCl3F + UV Cl + CCl2FCl + O3 ClO + O2
Cl + O Cl + O2
Repeated many times
Dangers of Ozone Depletion• Skin Cancer, cataracts, weaken immune
response
• Crop Damage, reduced yields
• Destruction of plankton (and the aquatic food chain)
• Other wildlife, especially amphibians
Greenhouse Effect• Greenhouse gases allow sunlight to penetrate
the atmosphere.• Absorbed by earth’s surface.• Reradiated as infrared energy (heat).
– Absorbed by gases.
• This warming of the atmosphere keeps the earth from freezing solid every night.
• The issue is too much of a change, too fast.
– 100 million years of carbon released in a hundred.
0100,000200,000300,000400,000500,000600,000Age (yr BP)
300
500
400
600
180
200
220
240
260
280
Tem
p. in
F°
CO
2 C
on
centratio
n
Today’s CO2 Concentration
Projected Concentration After 50 More Years of Unrestricted Fossil Fuel BurningProjected Concentration After 50 More Years of Unrestricted Fossil Fuel Burning
CO
2 [
pp
mv]
Year
0
1850 1875 1900 1925 1950 1975 2000 2025 2050 2075 2100
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0C
han
ge
in
te
mp
era
ture
(ºC
)
Greenhouse Effect
• Carbon Dioxide (70%)– Fossil fuel burning, land clearing.
• Chlorofluorocarbons (1%)– Refrigerants, cleaning solvents, propellants.
• Methane (10%)– Breakdown of organic material by anaerobic means.
• Nitrous Oxide (19%)– Biomass burning—Breakdown of nitrogen-rich
products.
Consequences of Global Warming
• Rising Sea Level– Beach and coastal wetland erosion.
• Disruption of Water Cycle– Navigation, Hydropower, Water Supply,
Recreation, Flood Control
• Worsening Health Effects– Expansion of tropical diseases
Consequences of Global Warming
• Changing Forests– Geographic distributions of vegetation.
• Challenges to Agriculture– Increased CO2 concentration likely to increase crop yields
in some areas and decrease yields in other areas.– Pest range expansion could increase vulnerability.
• Predictions based on computer models.
• Disruption of ecosystems – phenology
• Insects adapt and hatch earlier, birds, especially migratory ones, don’t.
• 3 species of penguins.
• The perm. resident is adapting and increasing.
• The 2 species that migrate to Antarctica to mate are declining.
• Increased deaths from heat and disease
• Disruption of food and water supplies
• Spread of tropical diseases to temperate areas
• Increased respiratory disease and pollen allergies
• Increased water pollution from coastal flooding
Human Health
• Rising sea levels• Flooding of low-lying islands
and coastal cities• Flooding of coastal estuaries,
wetlands, and coral reefs• Beach erosion• Disruption of coastal
fisheries• Contamination of coastal
aquifiers with salt water
Sea Level and Coastal Areas
• Changes in forest composition and locations
• Disappearance of some forests
• Increased fires from drying
• Loss of wildlife habitat and species
Forests
• Changes in water supply
• Decreased water quality
• Increased drought
• Increased flooding
Water Resources
• Shifts in food-growing areas
• Changes in crop yields
• Increased irrigation demands
• Increased pests, crop diseases, and weeds in warmer areas
Agriculture
• Extinction of some plant and animal species
• Loss of habitats
• Disruption of aquatic life
Biodiversity
• Prolonged heat waves and droughts
• Increased flooding from more frequent, intense, and heavy rainfall in some areas
Weather Extremes
• Increased deaths
• More environmental refugees
• Increased migration
Human Population
Addressing Climate Change
• Reduce Greenhouse Gas emissions.
• Improve energy efficiency.
• Increase amount of carbon dioxide removed from the atmosphere. (plants/sequestering)
• Use Bio-fuels instead of fossil fuels
• Halt deforestation
U.S. Emissions
0
0.5
1
1.5
2
2.5
3
1970 1990 2010 2030 2050
GtC
1.8
After Pacala and Socolow, 2004; ARI CarBen3 SpreadsheetAfter Pacala and Socolow, 2004; ARI CarBen3 Spreadsheet
2.6
Business as Usual
U.S. Stabilization
0
0.5
1
1.5
2
2.5
3
1970 1990 2010 2030 2050
GtC
2.6Electricity end-useefficiency
Other end-useefficiency
Passenger vehicleefficiency
Other transportefficiency
Renewables
CCS and Supplyefficiency
1.8
0.9
After Pacala and Socolow, 2004; ARI CarBen3 SpreadsheetAfter Pacala and Socolow, 2004; ARI CarBen3 Spreadsheet
1932 1988
Boulder Glacier
• Glacier National Park
Photos: George Grant, Glacier National Archive; Jerry DeSanto, national Park Service
Before 1980
1983
1985
1989
1993
1996
1999
2001
Wastage ofColumbia Glacier
Alaska
Meier and Dyurgerov, Science, 297, 2002Aerial photo taken 1996
U.S. Stabilization
0
0.5
1
1.5
2
2.5
3
1970 1990 2010 2030 2050
GtC
2.6Electricity end-useefficiency
Other end-useefficiency
Passenger vehicleefficiency
Other transportefficiency
Renewables
CCS and Supplyefficiency
1.8
0.9
After Pacala and Socolow, 2004; ARI CarBen3 SpreadsheetAfter Pacala and Socolow, 2004; ARI CarBen3 Spreadsheet