Lesson plan “ Ozone depletion”
1. Show the lesson plan. Divide the class into groups (5’)
2. How does ozone form? How is it destroyed? https://www.youtube.com/watch?v=WE3y1Gj2dec
(2’)
3. Read page 173: sources of ozone depleting chemicals (5’)
4. Page 173: the destruction of ozone by free chlorine: write a description of the diagram (10’)
5. Read Ozone layer depletion: health and environmental impacts of ozone depletion. (10’)
6. Exercise : crosswords (15’)
7. Time ? Post test: fill in the gaps
Homework: Answers page 174
Ozone layer depletion: a hole in the sky
Ozone (O3) is a pale blue colored gas which consists of three oxygen atoms, and creates
a shield for us in the Earth’s stratosphere, about 160,000 feet above the Earth’s surface. It
absorbs most of the Sun’s UV radiation. Scientists believe that as global warming and
greenhouse gases increase in the atmosphere, the protective ozone layer will get weaker.
This is because as the Earth’s surface temperature rises, the stratosphere will get colder,
making the natural process of ozone layer repair slower.
The ozone layer, which protects life on Earth from the harmful rays of the Sun has been
depleting for many years now. This is due to greenhouse gases and an increase in air
pollution, despite the progress made over the years since the Montreal Protocol which took
effect in 1989.
Currently scientists have identified more ozone depleting gases such as that HCFCs and
HFCs which are potent greenhouse gases, destroying the high-altitude ozone layer and
exposing us to harmful ultraviolet rays of the sun. (TreeHugger)
Ozone layer- the latest NASA Pictures
According to an article posted at the National Aeronautics and Space Administration,
NASA’s official website, titled NASA Visible Earth: Largest-ever Ozone Hole over
Antarctica, NASA’s instruments have detected that the ozone layer over the Antarctic
region, which scientists call an “ozone depletion area,” has grown three times larger than
the entire land mass of the United States—the largest such area ever observed.
In another article published on the NASA Science site, titled: 2014 Ozone Hole Update
NASA has said that “The Antarctic ozone hole reached its annual peak size on Sept. 11,
according to scientists from NASA and the National Oceanic and Atmospheric
Administration (NOAA). The size of this year’s hole was 24.1 million square kilometers (9.3
million square miles) — an area roughly the size of North America.”
The images found on the NASA’s public domain show the “hole” on September 11 and
September 30th of 2014. The single-day maximum area was similar to that in 2013, which
reached 24.0 million square kilometers (9.3 million square miles). The largest single-day
ozone hole ever recorded by satellite was 29.9 million square kilometers (11.5 million
square miles) on Sept. 9, 2000. Overall, the 2014 ozone hole is smaller than the large
holes of the 1998–2006 period, and is comparable to 2010, 2012, and 2013.
Since the Montreal Protocol came into effect, the ozone-depleting substances over
Antarctica has declined about 9% below the record maximum recorded in the year
2000.(Source: 2014 Ozone Hole Update – NASA Science)
The Health & Environmental Impacts of Ozone Depletion
The ozone layer of the stratosphere filters out most of the harmful ultra violate radiation
and shortwave radiation from the sun. If the ozone layer is depleted, then more harmful
rays will reach the surface of the Earth, which could have serious impacts on human
health, plants, animals, and environment. The impacts of depleted ozone are given below.
1. Effects on Human Health
In laboratory and epidemiological studies, it has been found that the Sun’s UVB rays
cause nonmelanoma skin cancer and plays a major role in malignant melanoma
development. UV rays have also been linked with cataract, a disease that clouds the
lenses of the eyes and causes blindness. It is therefore important to protect your skin and
eyes from Sun’s UVB rays.
2. Effects on Plants
UVB rays will affect agriculture, forestry and natural ecosystems. Plants’ growth and
metabolism are greatly affected by the amount of UVB present in sunlight. Even though
plants are equipped with repair mechanisms to reduce these effects, UVB radiation can
directly affect plant growth, competitive balance, bio-geochemical cycles and cause plant
diseases.
3. Effects on Marine Ecosystems
In particular, plankton (tiny organisms in the surface layer of oceans) are threatened by
increased UV radiation. Plankton are the first vital step in aquatic food chain. Decreases in
plankton could disrupt the fresh and saltwater food chains, and lead to a species shift in
our waters. Loss of biodiversity in our oceans, rivers and lakes could reduce fish yields for
commercial and sport fisheries. (Source: bcairquality.ca)
4. Effects on Biogeochemical Cycles
Increases in solar UV radiation could affect terrestrial and aquatic biogeochemical cycles.
It would alter greenhouse and chemically-important trace gases e.g., carbon dioxide
(CO2), carbon monoxide (CO), carbonyl sulfide (COS) and possibly other gases, including
ozone.(Source: epa.gov)
5. Effects on Materials
The Sun’s harmful radiationis known to cause damage to most synthetic polymers,
biopolymers, naturally occurring as well as some other commercial materials. The
materials available today are somewhat protected by an additive layer, but any increase in
the UVB levels would breakdown materials faster.
So, now you know the dangers of Sun’s Ultra Violet rays. Always take precaution when
you leave the house and are exposed to sunlight, especially when leaving the house
between the hours of 10 AM and 3 PM. Use plenty of sun block and use protective glasses
for your eyes.
We should also take precautions to protect the globe and our environment and do things
that reduce our negative impacts on the globe. Use materials that do not deplete the
ozone, such as using air conditioners, refrigerators and aerosols that do not contain any
CFC or other ozone depleting gases. We can all try to do things that reduce our overall
impact on the globe so that we can improve the general health of the planet, and make the
planet safer for future generations to come.
Source: Environmental Professionals Network
Credit: Science@NASA
Ozone layer depletion: a hole in the sky
Ozone
(O3) is a
pale blue
colored……………….. which
consists of
three………………………….. atoms, and creates a ……………………..for us in the Earth’s
………………………….. about 160,000 feet above the Earth’s surface. It absorbs most of
the Sun’s ………………………………. Scientists believe that as global warming and
greenhouse gases increase in the atmosphere, the protective ozone layer will get
……………………... This is because as the Earth’s surface temperature rises, the
stratosphere will get …………………, making the natural process of ozone layer repair
………………….
The ozone layer, which protects life on Earth from the………………………. rays of the Sun
has been depleting for many years now. This is due to …………………………and an
increase in air ………………………………, despite the progress made over the years since
the Montreal Protocol which took effect in 1989.
Currently scientists have identified more ozone depleting gases such as that
…………………………………. and HFCs which are potent greenhouse gases, destroying
the high-altitude ozone layer and exposing us to harmful ………………………….of the sun.
(TreeHugger)
Weaker
UV radiation
ultraviolet rays
stratosphere,
slower
shield
pollution
oxygen
HCFCs
harmful
greenhouse
gases
gas
colder
The Health & Environmental Impacts of Ozone Depletion
The ozone layer of the stratosphere filters out most of the harmful ultra violet radiation and
shortwave radiation from the sun. If the ozone layer is depleted, then more harmful rays
will reach the surface of the Earth, which could have serious impacts on human health,
plants, animals, and environment. The impacts of depleted ozone are given below.
1. Effects on Human Health
In laboratory and epidemiological studies, it has been found that the Sun’s UVB rays
cause nonmelanoma skin cancer and plays a major role in malignant melanoma
development. UV rays have also been linked with cataract, a disease that clouds the
lenses of the eyes and causes blindness. It is therefore important to protect your skin and
eyes from Sun’s UVB rays.
2. Effects on Plants
UVB rays will affect agriculture, forestry and natural ecosystems. Plants’ growth and
metabolism are greatly affected by the amount of UVB present in sunlight. Even though
plants are equipped with repair mechanisms to reduce these effects, UVB radiation can
directly affect plant growth, competitive balance, bio-geochemical cycles and cause plant
diseases.
3. Effects on Marine Ecosystems
In particular, plankton (tiny organisms in the surface layer of oceans) are threatened by
increased UV radiation. Plankton are the first vital step in aquatic food chain. Decreases in
plankton could disrupt the fresh and saltwater food chains, and lead to a species shift in
our waters. Loss of biodiversity in our oceans, rivers and lakes could reduce fish yields for
commercial and sport fisheries. (Source: bcairquality.ca)
4. Effects on Biogeochemical Cycles
Increases in solar UV radiation could affect terrestrial and aquatic biogeochemical cycles.
It would alter greenhouse and chemically-important trace gases e.g., carbon dioxide
(CO2), carbon monoxide (CO), carbonyl sulfide (COS) and possibly other gases, including
ozone.(Source: epa.gov)
5. Effects on Materials
The Sun’s harmful radiations known to cause damage to most synthetic polymers,
biopolymers, naturally occurring as well as some other commercial materials. The
materials available today are somewhat protected by an additive layer, but any increase in
the UVB levels would breakdown materials faster.
So, now you know the dangers of Sun’s Ultra Violet rays. Always take precaution when
you leave the house and are exposed to sunlight, especially when leaving the house
between the hours of 10 AM and 3 PM. Use plenty of sun block and use protective glasses
for your eyes.
OZONE ACTIVITY
BOOK
1
World Ozone Day - September 16th
© Environmental Management Authority 2004
Let’s talk about Ozone
are carried into the stratosphere by strong
Ozone & Ozone Layer Depletion
winds, which can take from two to five years.
Ozone is a naturally occurring gas that is
When CFCs break down in the stratosphere,
found
the
they release chlorine. Each chlorine atom
atmosphere. In the layer around the Earth's
attacks ozone by joining with and breaking
surface (the troposphere), ground level or
apart as many as 100,000 ozone molecules
bad ozone pollutes the air causing smog. In
during the time it is in the stratosphere.
the upper layer (the stratosphere), good
Other ozone eating chemicals are pesticides
ozone protects life on Earth by absorbing
such as methyl bromide, halons used in fire
some of the ultra violet (UV) rays given out
extinguishers, and methyl chloroform used
by the sun.
in industries and businesses. These ozone-
in
two
different
layers
of
eating chemicals can last many many years
The ozone layer is made up of ozone
in the stratosphere, where they continuously
molecules, like Ozzy Ozone, and forms a
destroy thousands of ozone molecules.
thin shield high up in the sky. Each ozone
molecule contains three oxygen atoms. It
What Is Being Done?
protects life on Earth from the sun's
ultraviolet (UV) rays. In the 1980s, scientists
Countries around the world have seen the
began finding clues that the ozone layer was
threats created by ozone depletion and
being depleted. This depletion would allow
made an agreement called the Montreal
more UV radiation to reach the Earth's
Protocol. This Protocol seeks eliminate the
surface. Too much UV can cause bad health
use
effects like skin cancer, eye damage, and
worldwide and will help us to save Ozzy
weaken your resistance to fight diseases.
Ozone and the Ozone Layer!
In
the
past,
chemicals
of
these
ozone-eating
chemicals
called
chlorofluorocarbons (CFCs), which are also
gases,
were
used
a
lot
in
industrial
equipment such as refrigerators and air
condition units to keep things cold, and to
make foam and soaps. When these CFC
gases are released in the atmosphere they
So let’s see what you know
about Ozone Science and
how you can help save Ozzy
Ozone and the Ozone
Layer…
Adapted from Sunwise Kids (USEPA)
2
World Ozone Day - September 16th
© Environmental Management Authority 2004
Test your knowledge of ozone layer science and ozone depletion in this
crossword puzzle
1
3
6
2
4
5
7
9
8
10
11
12
13
14
15
16
17
Across
•
•
•
•
•
•
•
•
3. Microscopic animals harmed by excess UV
6. Especially harmful band of UV radiation
11. One atom of this can destroy over 100,000 ozone molecules
12. Unnatural thinning of the ozone layer by human activities
13. Skin ___: One of the worst diseases caused by too much sun
14. ___ conditioning: one type of equipment that uses CFCs
15. Unit for measuring column ozone
17. ___osphere: Part of the atmosphere containing the ozone layer
Down
•
•
•
•
•
•
•
•
•
1. The southernmost continent; location of the ozone hole
2. Wind pattern over Antarctica that isolates the ozone hole
4. Ozone ___: region containing most atmospheric ozone
5. Montreal ___: Treaty protecting the ozone layer
7. Chemical that makes methyl bromide an ozone-depleting substance
8. Molecule that absorbs UVB radiation from the sun, protecting Earth
9. A substitute for CFCs that's much less damaging to the ozone layer but may cause global
warming
10. Ultra___: Harmful solar radiation
16. Abbreviation for gases that deplete the ozone layer
3
World Ozone Day - September 16th
© Environmental Management Authority 2004
See if you can find these words associated with
Ozone Science and Ozone Depletion
P
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Montreal Protocol
Refrigerant
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Halon
Phase out
Ozone
Layer
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Dobson
BFC
Vortex
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Protection
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Destroy
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Polar
United Nations
Hole
Chlorine
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Fumigant
Retrofit
Plankton
Cancer
4
World Ozone Day - September 16th
© Environmental Management Authority 2004
See if you can unscramble these words
associated with ozone science and ozone depletion
RACNEC
EOZNO
TRFEIRREGAN
KSCUONBL
LMOANTRE
STXEGINSUISREH
RAYLE
SLARESO
ESATUHPO
NITONELPDE
ULAELBRM
CSANOBROHDYR
SASESNUGLS
ESRTERSOTAHP
ECHORLNI
5
World Ozone Day - September 16th
© Environmental Management Authority 2004
See if you are a smart ozone shopper …
what would you buy?
OzoMart
Wide brim hat
Armless vests
Spray-can using
CFC
Long pants
CFC
Sun block SPF 45
Umbrella
UV Protected
Sunglasses
Long sleeve shirt
Sun block SPF 8
Halon Fire
extinguisher
Tank Top
Beanie Hat
Halon
Perfume Operated
by Pump
Refrigerator using
Hydrocarbons
Spray-can using
CO2
CFC-12
Refrigerator
CO2
6
World Ozone Day - September 16th
© Environmental Management Authority 2004
See if you can pick the odd one out in these groups
and figure out what the rest have in common
1. Montreal
Agreement
Protocol
Toronto
2. Sunglasses
Long pants
Strapless top
Wide brim
hat
3. Mesosphere
Earthsphere
Troposphere Stratosphere
4. SPF 8
5. Aerosols
6. Chlorine
SPF 35
SPF 20
Extinguishers Refrigerators
Bromine
Hydrogen
SPF 15
Toasters
Halon
7
World Ozone Day - September 16th
© Environmental Management Authority 2004
Crossword Answers
3P
6
U
7B
A
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10
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V
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H
A
2
A
N
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T
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5P
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8
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9
11
4L
1
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A
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12
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13
A
N
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14
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15
16
D
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17
T
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A
T
B
S
O
N
C
E
O
N
L
S
S
Across
•
•
•
•
•
•
•
•
3. Microscopic animals harmed by excess UV
6. Especially harmful band of UV radiation
11. One atom of this can destroy over 100,000 ozone molecules
12. Unnatural thinning of the ozone layer by human activities
13. Skin ___: One of the worst health effects of too much sun
14. ___ conditioning: one type of equipment that used CFCs
15. Unit for measuring column ozone
17. ___osphere: Part of the atmosphere containing the ozone layer
Down
•
•
•
•
•
•
•
•
•
1. The southernmost continent; location of the ozone hole
2. Wind pattern over Antarctica that isolates the ozone hole
4. Ozone ___: region containing most atmospheric ozone
5. Montreal ___: Treaty protecting the ozone layer
7. Chemical that makes methyl bromide an ozone-depleting substance
8. Molecule that absorbs UVB radiation from the sun, protecting Earth
9. A substitute for CFCs that's much less damaging to the ozone layer but may cause
global warming
10. Ultra___: Harmful solar radiation
16. Abbreviation for gases that deplete the ozone layer
8
World Ozone Day - September 16th
© Environmental Management Authority 2004
N
Word Sleuth Answers
P
B
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S
Ozone Word Scramble Answers
Cancer
Sun block
Layer
Depletion
Sunglasses
Ozone
Montreal
Aerosol
Umbrella
Stratosphere
Refrigerant
Extinguishers
Phase out
Hydrocarbons
Chlorine
9
World Ozone Day - September 16th
© Environmental Management Authority 2004
Ozomart Answers
Ozone Wise Products
Wide Brim Hat
Provides protection from the sun
Sunglasses
(UV radiation)
Long sleeve shirt
Umbrella
Sun block SPF 45
Spray-can using CO2
All items using CFC alternatives
(ozone friendly)
Refrigerator Using Hydrocarbons
Perfume Operated by Pump
Ozone Damaging Products
Does not provide adequate protection
from the sun
Armless vests
Short pants
(UV radiation)
Tank top
Beanie hat
Spray-can using CFC
Sun block SPF 8
Halon Fire extinguisher
Uses chemicals that are ozone
depleting (Halon & CFC)
CFC -12 Refrigerator
10
World Ozone Day - September 16th
© Environmental Management Authority 2004
One of these things is not like the other….
Answers
Groups
Reason
1. Montreal Agreement
Protocol
All refer to the Montreal Protocol and
international agreement for countries to
protect the ozone layer
(Toronto is a place in Canada but is not part of the title
of the agreement Montreal Protocol).
2. Sunglasses, long pants,
wide brim hat
These are all articles of clothing that protect
from UV radiation
(Strapless tops do not provide adequate protection for
your skin from UV Radiation)
3. Mesosphere,
Troposphere, stratosphere
These are all parts of the atmosphere
(Earthsphere is not a word)
4. SPF 35, SPF 20, SPF 8
All provide adequate protection from the sun
(SPF 8 does not provide adequate protection for your
skin from UV Radiation)
5. Aerosols, extinguishers,
refrigerators
All use chemicals that could deplete the
ozone layer
(Toasters do use chemicals that are harmful to the
ozone layer)
6. Chlorine, Bromine, Halon
All gases which are ozone depleting
(Hydrogen gas is not harmful to the ozone layer)
11
World Ozone Day - September 16th
© Environmental Management Authority 2004