Download Climate and Atmospheric Changes

OZONE DEPLETION &
CLIMATE CHANGE
(Ch 20)
ELECTROMAGNETIC SPECTRUM
UV – A (AGING):
Low energy.
Thought to contribute to
premature aging and wrinkling
of the skin and has recently been
implicated as a cause of skin
cancer.
UV – B (BURNING):
Medium energy.
UVB is more dangerous than
UVA and has been implicated as
a major cause of skin cancers,
sunburning and cataracts.
UV – C:
High energy.
UVC is extremely dangerous but
does not reach the earth’s
surface due to absorption in the
atmosphere. Most of the
radiation below 290 nm is
absorbed by the ozone in the
upper atmosphere. Depletion of
this layer increases the amount
of UVC reaching ground level.
TYPES OF UV RADIATION
HEALTH
OZONE LAYER DECREASES…. INCREASED UV
RADIATION ENTERS
Decreased
primary
productivity
(land & ocean)
Damage to
fish/amphibians
/ mammals
Disrupt food
chain
Effects on food
crops (beans,
wheat, rice,
corn)
IMPACTS ON ENVIRONMENTAL SYSTEMS
ATMOSPHRE
LAB
Cumulative Graph should look
like…
OZONE DEPLETION
 Ozone- molecule consisting of 3 oxygen
atoms
 Benefit
to humans because it
absorbs harmful UV radiation
 Ozone layer is being depleted because of the
addition of chemicals (esp. CFC’s) that break
apart the ozone molecule
OZONE VIDEO (2:20)
CHEMICAL CLASSES OF OZONE DESTROYERS
CHLOROFLOUROCARBONS
(CFC'S)
HALOCARBONS/HALONS
(ODS)
 No significant natural
 Highly reactive group 17
sources identified
 Source: Air
conditioning, Aerosol
propellants, solvents,
styrofoam
 GREAT longevity

takes 5-7 years for CFC’s to
go from ground to upper
atm.

Cl, Br, F
 Sources: Styrofoam,
Solvents, Soil Fumigant,
Fire Extinguishers
OZONE PHLEMISTRY WKST
O2 becomes O3
1)O2 + UV  ●O + ●O
2) O2 + ●O  O3
O3 becomes O2
1)O3 + UV  O2 + ●O
2) O3 + ●O  O2 + O2
CFCs degrades O3 into O2
1)CCl2F2 + UV  ●CClF2 + ●Cl
2) ●Cl + O3  ClO● + O2
NO degrades O3 into O2
1) NO + O3  NO2 + O2
AIRPLANES!
OZONE CHEMISTRY
for the visual learners
STEP 1:
NATURAL FORMATION OF OXYGEN
STEP 2: Natural Formation of Ozone in the
STRATOSPHERE
Step 3: Natural Breakdown of Ozone in the
STRATOSPHERE
STEP 4: CFC’s BREAKING DOWN OZONE
(anthropogenic causes)
Free Radical
Chlorine
CFC
OZONE
Oxygen
Free Radical
Oxygen
CLO*
PER CHLORINE ATOM BROKEN OFF BY UV RADIATION FROM CFC’S,
100-300,000 OZONE MOLECULES CAN BE BROKEN DOWN
(~900,000 O3 MOLEUCLES PER CFC!)
Ozone over Antarctica
ANTARCTIC OZONE HOLE (16 MIN)
OZZY OZONE (10 MIN)
THOMAS MIDGLEY
CLIMATE CHANGE
Long-term change in the earth's climate,
especially a change due to an increase in the
average atmospheric temperature.
CLIMATE CHANGE - GLOBAL WARMING
GLOBAL WARMING
OR CLIMATE
CHANGE?
GLOBAL WARMING
INDICATES THAT THE
GLOBAL
TEMPERATURE IS
INCREASING AND IT IS
GETTING HOTTER
EVERYWHERE.
CLIMATE CHANGE
INDICATES THAT
CLIMATES ARE
SHIFTING AND
UNCHARACTERISTIC
WEATHER PATTERNS
WILL ARISE
WHEATHER THAT IS
HOTTER OR COOLER,
WETTER OR DRYER.
There is absolutely ZERO debate that global
temperatures have gone up and down for centuries
GREENHOUSE EFFECT
Causes of
Climate Change
Description of what it is
Explanation of how it impacts
climate
(What SCIENTISTS say)
Volcanic
eruptions
When volcanoes erupt, they release
dissolved gases (like carbon dioxide,
water vapor and sulfur dioxide) into the
atmosphere
Adds to the build-up of Greenhouse
Gases
Sunspots
More emitted radiation and increased
More sunspots will increase the amount
temperatures are found around sunspots of heat that stays within the atmosphere.
Earth’s orbit
There is variation in Earth’s tilt which
affects the amount of solar radiation
received.
Depending on the season, more or less
energy is received from the sun.
Carbon
Dioxide
fluctuations
As heat is reflected back out into space,
carbon dioxide (CO2) absorbs some of the
heat.
Heat is retained in the atmosphere (not
radiated back into space) causing the
global temperature to rise.
TRENDS IN ATMOSPHERIC CO2
Effects of Climate Change
Link: The Nature Conservancy
1. HIGHER
TEMPERATURES
The five hottest years on record
have all occurred since 1997.
2. CHANGING
LANDSCAPES
Changing patterns of rain and
snow are forcing trees and plants
around the world to move toward
polar regions and up mountain
slopes
ALASKA - Portage Glacier
1914
2004
ARIZONA- Colorado River
June 2002
Dec 2003
Effects of Climate Change
3. WILDLIFE AT RISK
Rising temperatures are
changing weather and
vegetative patterns across the
globe, forcing animal species to
migrate to new, cooler areas in
order to survive.
4. RISING
SEAS
Experts predict
that 1/4 of Earth’s
species will be
headed for
extinction by 2050
Sea level rise from
climate change could
displace tens of millions
of people. Sea levels
could continue to rise
between 4 inches and 36
inches over the next 100
years.
Effects of Climate Change
5. INCREASED RISK OF
DROUGHT, FIRE & FLOODS
Massive land erosion is one
result of overgrazing &
drought in Kenya
6. STRONGER STORMS
& HURRICANES
Hurricanes and tropical
storms to become more
intense — lasting
longer, unleashing
stronger winds, and
causing more damage to
coastal ecosystems
Effects of Climate Change
7. MORE HEAT RELATED
ILLNESS & DISEASE
As temperatures rise, so do the risks of
heat-related illness and even death for the
most vulnerable human populations.
Increase the spread of infectious diseases.
8. ECONOMIC LOSSES
Climate change could cost between 5 and
20 percent of the annual global gross
domestic product. Declining crop yields
could put hundreds of thousands of
people at risk for starvation.
Effects of Climate Change
9. OCEAN
ACIDIFICATION
As temperatures rise, so does the
amount of carbon dioxide in the
ocean causing acidic water.
10. EL NINO & LA NINA
Weather patterns in the Pacific
Ocean change causing an
increased frequency of bad
weather events to occur around
the world.
Global Atmospheric Concentration of CO2
CLIMATE CHANGE CONTROVERSY?
NOT FOR
SCIENTISTS!
My personal opinion
The way I see it….
WHAT CAN YOU DO
TO HELP SLOW
DOWN GLOBAL
CLIMATE CHANGE?
Neil deGrasse Tyson, Astronomer
makes a very good point...
1000 Years of CO2 & Global Warming
Temperature
(Northern Hemisphere)
Year
Year
2000
1800
1600
1400
1200
1000
2000
1800
1600
1400
1200
1000
Parts Per Million
Degree Celsius Increase
CO2 Concentrations
Billions of Metric Tons Carbon
Goal:
Reductions in
2007
CO2 Per Year
of Metric
Billions
CarbonTons Carbon
Gigaton
Our Goal
2007
Reductions
in CO2
Per Year
Produce electricity
efficiently
Use electricity
efficiently
Vehicle efficiency
Solar and Wind
Power
Biofuels
Carbon capture
and storage
How ozone is destroyed by CFCs