BLM 14
The history of the
ozone
1898
Teisserenc de Bort discovers the stratosphere and the troposphere.
1913
Charles Fabry discovers the ozone layer, a thin layer of air 10-50 km in the
stratosphere, protecting the earth from too much ultraviolet radiation.
1928
Chlorofluorocarbons (CFCs) are invented by Thomas Midgely working at Du Pont
Corporation, for use in refrigerators.
1950s
CFCs used widely in industrialised countries as propellants in aerosol cans, in
refrigerators, in air conditioning systems and in the manufacture of foam packaging.
1970s
F Sherwood Rowland and Mario José Molina calculate the damage CFCs make to the
ozone layer.The public becomes alerted by newspaper articles.
1985
International research is carried out and satellite photographs confirm the existence
of a hole in the ozone over Antarctica.
1987
International action in the form of a United Nations treaty called the Montreal
protocol. Agreement is reached to phase out most CFC production by 1996.
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BLM 15
The History of the Ozone Layer
layer
1995
CFC-free fridges. CFCs not manufactured in most countries. However, scientists have
discovered that ultraviolet radiation is causing skin cancers and other health
problems for humans and other animals.
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Teaching notes for
The History of the Ozone Layer
Text form:
Medium:
Field:
Tenor:
Mode:
Timeline
Magazine
The history of the ozone layer
Expert to general audience
Written
and encourage them to reference the information.
Remind students of the correct structure and
grammar of an information report. Encourage them
to consult with other students to revise and redraft
their texts. Provide time for editing and proofreading
before presentation.
IT’S
OTHER
RESOURCES
Draft writing paper.
Chart paper.
Overhead projector for student presentations.
Access to resources that provide information about
the ozone layer and CFCs.
INTRODUCING
THE UNIT
By this stage students should be very familiar with the
social purpose and typical structure of the
information report. They need to explore a variety of
ways that information can be presented such as in
grids, graphs, matrices, maps, diagrams, photographs,
signs and, as in this unit, timelines.
This text is a timeline representing the history of the
ozone layer. Find out what students know about the
ozone layer and their responses to these facts. Ask
students to use dictionaries to write definitions for
these terms: stratosphere, troposphere,
chlorofluorocarbons, ozone layer, ultra violet radiation.
Ask students to predict what the timeline might say
for the years 2000, 2010 and 2020. Discuss their
predictions, listing them under headings of positive
and negative.
STORYBOARD
Students should create symbolic representations of the
issues and events for each date. Encourage them not to
draw literally what is happening. Ensure that they
understand that visual texts represent points of view
about topics. The symbols and images they choose for
each date should present their point of view.
RESEARCH
AND WRITE
Remind students of the importance of the currency
of information. Ensure that they make careful notes
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PRESENTATION TIME!
Suggest a variety of ideas to be used in a stimulating
presentation. Observe how well students engage their
audience’s interest and attention. Observe their use of
voice and body language as well as their use of visual
aids such as overhead projectors, illustrations and
photos.
EXTRA! EXTRA!
READ ALL ABOUT IT!
Encourage students to adequately research their topic
before they begin writing. Ensure that they
understand the importance of developing field
knowledge in order to write (or speak) effectively.
Display and discuss students’ newspaper articles.
FOLLOW-UP/EXTENSION
• Explore neologisms that have occurred due to
scientific discovery and technology, e.g.
chlorofluorocarbons.
• Encourage students to explore the spelling patterns
in some of the words in the timeline, e.g.
chlorofluorocarbons.
• Have students explore a variety of ways that
information can be presented such as in grids,
graphs, matrices, maps, diagrams, photographs, signs,
and timelines. Teach students how to construct and
deconstruct each of these.
• Encourage students to think about other inventions
and the benefits and damage they have caused, e.g.
plastic, preservatives, food colouring, petrol. Ask
students to select one of the inventions/discoveries
and work in groups to create a semantic web or a
flow chart for the topic.
Name _________________________________________ Date _______________
BLM 16
The History of the Ozone Layer
Storyboard
Draw an image for each date on the timeline. You may draw realistically, you
may draw cartoons or you may represent the ideas for each date symbolically.
1898
1913
1928
1950s
1970s
1985
1987
1995
NA 4.9 NSW 3.9 Writes well structured literary and factual texts using challenging topics, ideas and issues for a variety of purposes and audiences.
NA 4.10 NSW 3.13 Evaluates writing in terms of effectiveness of presentation of subject matter and adjusts to focus on context, purpose and audience.
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BLM 17
Name _________________________________________ Date _______________
The History of the Ozone Layer
Research and write
Research CFCs. Make sure that the information that you write is as current and
accurate as possible by checking the date of publication of any source you use. Make
research notes on scrap paper and then write your report in the grid below.
Opening
general
classification
or definition
Series of
facts in
paragraphs
It’s presentation time!
Prepare your information report for presentation to
other students in your class or students from other classes.
You might use photos, charts or an overhead projection to
make your presentation more interesting for your audience.
If you are making the presentation to another class you will
need to consider the students’ levels of prior knowledge
about the topic and make sure you define all the terms you use.
NA 4.8b Working with peers, is able to find information and resources for specific purposes.
NA 4.10 NSW 3.13 Evaluates writing in terms of effectiveness of presentation of subject matter and adjusts to focus on context, purpose and audience.
NA 4.11 NSW 3.14 Discusses and evaluates how texts have been constructed to achieve their purpose and shape readers’ and viewers’ understandings using
grammatical features and structures.
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Name _________________________________________ Date _______________
BLM 18
The History of the Ozone Layer
Extra! Extra! Read all about it!
Sometimes newspaper articles are called reports because they attempt to provide
information. However the information is sometimes sensationalised or a biased
viewpoint is presented. This is because the social purpose is to sell the newspaper so
that advertising can be sold. Keeping this in mind, write a newspaper article about the
events and issues for one of the dates in the timeline. You will probably need to do some
extra research first. Draft your article on scrap paper and then publish it below.
NA 4.9 NSW 3.9 Writes well structured literary and factual texts using challenging topics, ideas and issues for a variety of purposes and audiences.
NA 4.10 NSW 3.13 Evaluates writing in terms of effectiveness of presentation of subject matter and adjusts to focus on context, purpose and audience.
NA 4.11 NSW 3.14 Discusses and evaluates how texts have been constructed to achieve their purpose and shape readers’ and viewers’ understandings using
grammatical features and structures.
NA 4.12a NSW 3.10 Uses a range of strategies to plan, edit and proofread own writing.
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