Download Power Point - Effingham County Schools

Ozone Loss DOES NOT cause Global Warming!
≠
Ultraviolet waves are not Heat (infrared) waves!
Climate Change
https://www.youtube.com/watch?v=VXvGPbHXxtc&feature=youtu.be
Over past 4.7 billion years, climate has been altered by:
 Volcanic emissions
 Changes in solar input
 Movement of continents
 Impacts by meteors
 Changing global air & ocean circulation
Over the past 900,000 years:


Have alternated b/w glacial and interglacial periods
Over the past 10,000 years: Interglacial period (allowed for
rise of human civilization)


Over the past 1,000 years: Temperature stable
Over the past 100 years: Temperature changes
Global Temperatures
Average Surface Temperature (°C)
17
16
15
1
4
13
12
11
10
9
900
800
700
600
500
400
300
Thousands of Years Ago
200
100 Present
2
Temperature Change (°C)
1
0
-1
-2
End of
last ice
age
-3
Average temperature over past
10,000 years = 15°C (59°F)
-4
-5
20,000
10,000
2,000
1,000
Years Ago
200
100
Now
Average Surface Temperature (°C)
15.0
14.8
14.6
Heating
trend
14.4
14.2
14.0
13.8
13.6
1860
1880
1900
1920
1940
Year
1960
1980
2000
2020

Evidence


Ice cores - extracted by drilling deep holes into ancient glaciers
at various sites
 1,000s of ice cores are stored – Ex: National Ice Core Laboratory
in Denver
Scientists analyze air bubbles, layers of soot, & other materials
trapped in different layers to get info on:






past composition of lower atmosphere
temperature trends
greenhouse gas concentrations
solar activity
snowfall
forest fire frequency
Greenhouse EffectWithout it, Earth would be a frigid planet, with average temperature around zero degrees F
•Greenhouse Gases: absorb heat radiated by earth
– Then emit infrared radiation that warms the atmosphere
Main Greenhouse Gases:
Natural:
• Water vapor – main one
Human-Induced:
•
•
•
•
•
Carbon dioxide (CO2) – main concern
Methane (CH4)
Nitrous oxide (N2O)
CFCs
Ozone
• https://www.youtube.com/watch?v=OqVyRa1iuMc
Greenhouse Gases have increased b/c:
• Burning of fossil fuels: coal, oil and natural gas (  CO2 and
CH4)
• Deforestation ( CO2 and N2O)
• Clearing and burning of grasslands ( CO2 and N2O)
• Cattle & other livestock ( CH4)
• Inorganic Fertilizers ( N2O)
• Air pollution from VOCs ( O3)
Carbon Dioxide
Went from 280 ppm in 1950s to 389 ppm in 2010
Output has increased by 115% over the last 100 years
Methane
Levels in atmosphere have tripled in last 275 yrs
Nitrous oxide
Warming Trends:
– 20th century was hottest
century in past 1,000 years
– Since 1861, average global
temp of troposphere has
rise 0.6C (1.1F)
– The 16 warmest years on
record have occurred since
1980
– Glaciers & floating sea ice
are melting & shrinking
– During last century, sea
level rose by 0.1-0.2m
Climate Change
• Major Findings of the 2007/2009 Intergovernmental Panel on
Climate Change (IPCC) report:
1. Earth’s lower atmosphere is warming due to increased [ ]’s of
CO2 & other greenhouse gases
2. Most of the increase in [ ]’s of gases since 1960 is due to human
activities, esp. burning fossil fuels
3. Human-induced changes in composition & temp of atmosphere are
changing earth’s climate
4. If [ ]’s continue to increase, earth will experience rapid
atmospheric warming & climate disruption
5. Climate disruption  ecological, economic & social disruption by
degrading water & food supplies, flooding coastal communities, and
eliminating species
Effects of a Warmer Atmosphere
1. Drought: Affects growth of trees  less removal of CO2 
more climate change; Decreased surface water (water shortages) &
biodiversity
2. More ice & snow melt: Can lead to water shortages & flood
3. Permafrost melts: Will release significant amounts of CH4 and
CO2 – known as the methane time bomb (video)
4. Sea levels rising: Loss of coastal wetlands, coral reefs; Disruption of
fisheries; Flooding & displacement of coastal cities & islands; Saltwater
contamination of coastal aquifers
5. Extreme Weather: droughts, heat waves, blizzards, and especially
fewer but stronger hurricanes
6. Biodiversity loss: Hardest hit -Arctic & alpine species (polar bears,
penguins); Coral reefs & coastal wetlands; Specialist species – amphibians;
Higher temps lead to expansion of insects & fungi that harm trees
7. Agriculture: production may decrease in some areas & may increase in
others
8. Human health: Heat waves, Flooding & storms, Infectious diseases
(mosquitoes – malaria, yellow fever, dengue fever)
9. Ocean Acidification: the decrease in pH of oceans, caused by uptake
of carbon dioxide (CO2) from the atmosphere.
~30% of the CO2 released by humans into the atmosphere dissolves into
oceans, rivers and lakes.
Formula: CO2 + H2O  H2CO3- (carbonic acid)
Between 1751 – 1994: ocean pH is estimated to have decreased from ~8.25 to
8.14 = ~30% change in acidity!
Effects: Contributes to Coral Bleaching, Calcifiers can’t make shells as fast 
MAJOR EFFECTS ON FOOD WEBS!
Tipping points:
• Atmospheric Carbon levels of 445 ppm
• Melting of all arctic ice
• Severe ocean acidification & collapse of phytoplankton
communities
• Massive release of methane from thawing permafrost
• Severe shrinkage of Amazon rainforest
Major prevention strategies:
1.
2.
3.
4.
Cut fossil fuel use (esp. coal)
Shift to using renewable energy resources
Stop cutting tropical forests & plant trees
Shift to sustainable agriculture (less methane)
Cleanup Strategies:
1. Plants lot of trees or other plants (but where?)
2. Carbon Capture and Storage (CCS): pumping CO2 from coal
smokestacks underground
Government Intervention:
1. Regulate CO2 & CH4 as air pollutants
2. Carbon taxes/ fees
3. Subsidies & tax breaks for environmentally-sustaining
business & energy-efficient choices
4. Technology transfer: give developing countries the
technology to be more energy efficient
5. Cap & Trade Policies: put a total cap on allowable emissions,
give permits to polluters, and let them trade permits for
money
The Kyoto Protocol
• 1997: Treaty to slow climate change
• Phase 1 (began in 2005): Reduce emissions of CO2,
CH4, and N2O by 2012 to 5.2% of 1990 levels
• Not signed by the U.S.
Ozone
STRATOPSHIC Ozone protects earth’s surface from 95%
of harmful UV radiation
Concentration of ozone measured in dobson units (DU)
Ozone “Hole” - Thinning
• First noticed in 1978
• Antarctica Ozone hole season: August – October
(Ozone hole recovers by late December)
Ozone Depleting Compounds
•
•
•
•
•
•
Chlorofluorocarbons (CFCs) aka FREONS – main one
Halons – fire extinguishers
Methyl bromide (CH3Br) - fumigant
Carbon tetrachloride (CCl4) – cleaning solvent
Methyl chloroform (CH3CCl3) – cleaning solvent
Hydrogen chloride (HCl) – emitted by space shuttles
Chlorofluorocarbons (CFCs)
• Chemically stable, odorless “dream” chemicals
• First produced by General Motors Corporation in 1928
• Used in:
– propellant in aerosol (spray) cans
– cleaner for electronics
– refrigerant
1974:
Sherwood Rowland & Mario Molina proposed that CFC’s destroy ozone layer.
Findings:
CFCs are persistent in the troposphere
Over time, CFCs move into stratosphere, CFCs break down under UV radiation,
forming free chlorine atoms which convert O3 into O2 + O
1995:
Rowland & Molina received Nobel Prize in chemistry
Solutions
– Use substitutes to CFCs
– Montreal Protocol (1987)
• International treaty signed by 146 nations to cut production &
emissions of CFCs by 35% between 1989-2000
Ozone Depletion Effects:
• Sun burns & skin cancer, Cataracts and blindness, Suppression of immune
system
• Impact on plants & animals (health effects)
• Reduction in ocean phytoplankton *Disrupts aquatic food webs
• Affects fishing, forestry & agricultural industries
• Degradation of paints and plastic material
Atmosphere
Upper limit, where atm. merges into space
Auroras & space shuttles are found here
Meteors burn up here
Contains Ozone layer
1st layer where weather occurs
Sphere
Description
Exosphere
upper limit
Thermosphere
auroras & space shuttles
Mesosphere
meteors
Stratosphere
ozone layer (global sunscreen)
Troposhere
78% N2 21% O2 1% other (ozone is a pollutant here)
Pollutants
The World Health Organization estimates that 5-6 million people die prematurely every
year from illnesses related to air pollution
Anthropogenic Sources
Effects
Carbon monoxide (CO)
Burning of fossil fuels,
Cigarettes
Prevents blood from
carrying oxygen
Nitrogen oxides (NOx)
Burning of fossil fuels
lung damage &
cancer; acid rain due
to nitric acid (HNO3)
Sulfur dioxide (SO2)
Burning of coal
acid rain due to
sulfuric acid (H2SO4);
respiratory irritant
Volatile Organic
Compounds (VOC)
CH4, propane (C3H8),
paints, adhesives,
pesticides, formaldehyde
Burning of fossil fuels, and
using paints, glues, & solvents
Cancer, respiratory
irritant
Particulate Matter-soot,
dust, pollen, lead
construction, fire, industry,
agriculture
respiratory irritant,
cancer
Lead
Some fuel, smelters, metal
processing
Kidney & brain
damage
Natural Sources: volcanoes, forest fires
Primary Pollutant
Focus: Suspended
Particulate Matter (PM)
 Sources: incomplete
combustion of fossil
fuels (coal burning,
burning diesel & fuels
in vehicles),
agriculture,
construction
 Health effects: lung
damage, shortens life;
some cause cancer
 Black lung disease from
coal dust
Focus: Lead-Toxic metal emitted as particulate matter
– Sources: old paint, smelters, batteries, leaded gasoline
– Health effects: nervous system damage, retardation
How Stuff Works: Lead Poisoning
Focus: Ozone (O3)
Sources: rxn with VOCs & Noxs
Health/Env. effects:
breathing problems; lower immunity, damage plants
VOCs + NOx + heat + sunlight  photochemical oxidants (NO2, O3, PANs)
Secondary
Pollutant: Smog
Photochemical smog:
brown air smog
Forms when nitrogen oxides
& volatile organic
hydrocarbon compounds
react w/ UV rays
Found in modern cities,
especially in warm, sunny
areas.
Industrial smog:
aka “gray air smog”:
Decreased by Precipitation, Salty sea spray
Wind, Reduce factory/car emissions
Caused by burning of fossil fuels
Increased by Urban buildings,
Carbon in coal/oil converted to CO,
Hills and mountains, High temperatures
CO2 ,Sulfur converted to SO2,then H2SO4
Temperature Inversions
Secondary Pollutant: Acid Deposition: caused mainly
by coal-burning power plants and motor vehicle emissions
SO2 + O2  SO3+ H2O  H2SO4 (sulfuric acid)
NO2 + H2O  HNO3 (nitric acid)
Dry Deposition
Normal rain is slightly
acidic
- pHand
of particles.
about 5.6
 Acidic
gases
(due to CO2 + H2O  H2CO3 - carbonic acid)
Any rainfall with a pH value
<5.6 is defined as acid rain.
As of the year 2000, the most
acidic rain falling in the US has
a pH of about 4.3.
https://www.youtube.com/watch?v=HE6Y0iEuXMQ
http://www.youtube.com/watch?v=v09KnqiYi-c
http://www.youtube.com/watch?v=Nc6j7zz1_do
Health / Environmental Effects of Acid Deposition
•
•
•
•
•
•
•
Lung/respiratory problems
Degrade metal pipes, leading to water pollution
Damage to statues & buildings
Decrease soil pH (more acidic)
Decrease pH of rivers, lakes, ponds, etc
Sensitive Fish (and some amphibians) kills
Plants become susceptible to disease, parasites, etc
– Lower crop yields
Other Pollution Issues
Temperature Inversions: when layer of warm air traps layer
of cool air below it & prevents pollutants from dispersing
– Happens when cities are in valleys, surrounded by
mountains
“Grasshopper Effect”
–Volatile air pollutants evaporate in tropical & temperate
areas 
–Are deposited in areas of colder temperatures (arctic).
–Causes polar bears, sharks, whales, etc. to have high
levels of DDT, toxic metals, & PCBs in their bodies
https://www.youtube.com/watch?v=3CMlWQodtYs
Indoor Air Pollution
• 70 to 90% of time spent indoors, mostly at home
• Less air flow to remove pollutants
– Pollutants: cigarette smoke, formaldehyde, radon, ultrafine
particulates, pesticide residue & lead particles, dust mites,
cockroach droppings, mold, carbon monoxide, asbestos
– “Sick Building Syndrome” Typically newer buildings because of
less air leaks. Symptoms: headache, coughing, sneezing, tiredness.
Some scientists don’t believe this exists.
Focus: Radon
Naturally occurring from radioactive
decay of Uranium-238.
Occurs in soils, bedrock and can get
into homes through cracks.
Can’t get out and builds up in the home
Can lead to lung cancer
Focus:
Tobacco smoke- 12 million children exposed to
secondhand smoke in U.S. homes
– Associated with:
»
»
»
»
Sudden infant death syndrome
Lower respiratory tract illness
Middle ear disease
Asthma
Focus:
Formaldehyde (CH2O)
Found in: plywood, furniture, upholstery, floor adhesives, dry cleaning
chemicals
Causes: breathing problems, headache, sore throat, dizziness, eye irritation
in those sensitive to low levels
Chronic exposure to higher levels can lead to cancer
Health Effects of Air
Pollution
• Asthma
• Lung cancer
• Chronic bronchitis
• Emphysema
This map shows the distribution of premature deaths from air pollution
in the United States, mostly from very small, fine, and ultra-fine
particles added to the atmosphere by coal-burning power plants.
• According to WHO, 2.4 million people worldwide
die prematurely from air pollution
– Most in Asia (esp. China)
Other Forms of Air Pollution
– Light Pollution
• leads to:
– Wasted energy
– Affects animals’ biological cycles & migration
– Noise Pollution
• = pervasive noise, from unwanted to damaging
• Intensity of sound is measured in decibels (dB)
• For each 10-fold increase in dB, the sound intensity is 10X higher
(for example: 30 dB has 100x intensity of sound than 10 dB)
• Hearing Loss has doubled in US in last 30 years
• ~12% teens have permanent hearing loss
• 80 year old person in quiet Africa has better hearing than 30 year
old American
http://www.inquisitr.com/39454/marriage-proposal-ends-with-romantic-baby-sea-turtle-massacre/
Hearing Loss Test
Laws & Solutions:
•Clean Air Act (1970, 90, 99): fed gov established air pollution regulations
• EPA set air quality standards for 6 “Criteria Air Pollutants”: CO, NO2, SO2,
SPM, O3, and Pb
• In 1990, started emissions trading (aka cap-and-trade program) which gives
power plants rights to buy & sell pollution rights
• Required catalytic converter
• Corporate Average Fuel Economy (CAFE): requires vehicles
have a fuel efficiency average of 27.5 mpg
Devices:
– Catalytic converters: oxidizes VOCs & CO from car exhaust 
coverts to CO2
– Scrubbers: use fine mists of calcium carbonate (CaCO3) or
calcium oxide (CaO) solution to wash pollutants (esp. SO2) from
smoke
– Electrostatic precipitator: removes particles by giving them a
negative charge & attracting them to positive plates
• Wet Scrubber: to remove SO2
Dirty
gas
Cleaned gas
Clean water
Wet gas
Dirty water
Electrostatic Precipitator: to remove particulates
Cleaned gas
Electrodes
Dust discharge
Dirty gas