Lesson Write-Up For Winter Quarter 2012
Your name: Albert Medina
Title of Lesson: Greenhouse Gases: Effects on Environmental Warming
Grade Level: 8th Physical Science
Subject(s): Environmental Science, Reactions, Periodic Table
Summary:
This lesson introduces students to the idea of the greenhouse effect and how greenhouse
gases can contribute to heat retention leading to environmental warming on a global scale.
Various greenhouse gases, such as carbon dioxide, and their chemical composition are
identified for the students as well as their means of production, however their effects on
environmental warming are not yet revealed. Rather, students are tasked with
constructing a miniature earth composed of sand, gravel and foliage in a tank. Students
then expose their earth to the sun simulated by 75 watts heat lamps positioned above. The
temperature of the tank is monitored and measured during exposure for a case in which
only air resides inside the tank, as if their miniature earth has an atmosphere free of
greenhouse gas, and for a case in which the tank has been filled with carbon dioxide gas via
baking soda and vinegar reaction. In doing so, students then draw their own conclusions as
to what effects greenhouse gases may have on planet earth. Discussion continues to
ensure students do not leave with the impression that greenhouse gases are detrimental.
Said gases have proven quite helpful in promoting favorable temperatures for life on earth
in moderation.
Time Required:
90 minutes
Group Size:
3 students per group
Cost to implement:
Heat lamps~$150 (for 6 lamps, each shared by two groups); Other materials ~$15
Learning Goals:
After this lesson, students should be able to:
1. Identify common greenhouse gases
2. Cite their effects on heat retention on a given environment
3. Discuss how greenhouse gases have proven beneficial in moderation and detrimental
in excess
4. Provide steps populations can take to reduce the production of greenhouse gases
Level of Inquiry:
Students are given an introduction to certain chemical compositions that constitute
greenhouse gases. Students are not given any details as to heat retention capabilities of
greenhouse gases and are asked to hypothesize what is to happen to the temperature of
their earth for the various cases they will test. Students may become too fixated on the fact
that two cases will see an earth atmosphere with just air and the third case with a
greenhouse gas to realize that the temperature of the air atmosphere case should still see a
rise in temperature. Additionally, closing discussions include the students coming up with
steps a population could follow to reduce greenhouse emissions.
Introduction / Motivation:
Greenhouse gases are found in the atmosphere above the earth’s surface. Begin by asking if
students are familiar with or have heard of greenhouse gases and in what context. Many of
which will be quick to point out its association with global warming but they will not be
able to provide much more insight into the process of global warming. Just as the name
implies, they will be able to deduce greenhouse gases are either promoting or retarding
warming of the environment. Open a discussion and allow students to share how rising
temperatures may affect a population.
This lesson is best implemented just as the students have developed an appreciation for the
periodic table. Students are now familiar with individual elements and their characteristics
but now they will develop an appreciation for some of the many chemical compositions the
elements can create and how they could have an impact of the quality of life. Beginning
with presentation 1, students are introduced to a few of the greenhouse gases, namely
carbon dioxide, with emphasis on the elements involved. Continue by identifying some of
the means of production of greenhouse gases. For example, carbon dioxide as a byproduct
of combusting fuel with applications to automobiles and factories. Students would also be
surprised to hear they exhale carbon dioxide and are active contributors to greenhouse gas.
Carbon dioxide production.
Methane production.
Keep in mind students still have not been formally introduced as to what the effects
greenhouse gases may have on the temperature of an environment. To address this,
students are now taken directly into the lab.
Lesson Background Concepts for Teachers:
The Kyoto Protocol is a worldwide effort to limit greenhouse gas emissions being released
into the atmosphere. The protocol recognizes industrial nations produce pollution and
places a cap or limit on the amount of allowable pollution a given country may safely
produce. Most scientists strongly believe human activity has contributed to global climate
change by greenhouse gas production. It is also believed we can prevent global warming
and climate change by limiting our production of greenhouse gases. Most of the gas
produced is a byproduct of burning fossil fuels, such as oil, gas or coal, for energy to use in
households, automobiles and manufacturing plants. Landfill gases also contribute to
greenhouse gases by means of decomposition of organic materials.
Procedure:
At the completion of the first presentation, instruct the students to construct a miniature
earth in a tank provided. It should include sand, gravel and foliage to represent a natural
environment. Their environment is to be exposed to a miniature sun represented by the
heat lamp provided.
Miniature earth and sun.
Over the course of ten minutes, students are to measure the temperature of their earth
environment every minute with the environment starting at room temperature. This is to
be conducted for a total of 3 cases as follows:
1. Environment with just air
2. Environment containing vinegar and baking soda separated (not mixed yet)
3. Environment containing carbon dioxide product of vinegar and baking soda mixture
Students should be given a moment to discuss with their group and write down their
hypothesis for the temperature behavior of the environments for all three cases in
response to heating on the worksheet provided. Before beginning any of the three cases,
students should be sure to allow sufficient time for their earths to cool down and return to
room temperature. All temperature measurements are recorded on the worksheet in the
proper column.
Once temperatures are recorded, the students are also asked to plot their findings. Here
we begin with presentation 2 which starts with a sample of how their plot shouls look.
Students should find the temperature of case 3 which saw the tank or miniature earth’s
atmosphere filled with carbon dioxide rise to higher temperatures than the other two
cases. So now it should be clear greenhouse gases help trap heat from the sun and we
continue in presenting to the students why this is so.
Greenhouse effect.
Solar radiation from the sun readches earth’s atmosphere. Some of the radiation is
reflected by the atmosphere while some of the solar heat passes right through the
atmosphere and warms up the earth. As the earth warms up, it can be likened to a pie fresh
from the oven. The pie has steam coming from the surface as it releases heat to the
surroundings; so too is the case of the earth, it releases heat into space like the pie cooling
off. Some of the heat released passes back out through the atmosphere into space but we
have keep in mind our atmosphere is filled with greenhouse gases. These gases work to
absorb and redirect the heat leaving earth, effectively trapping it within the atmosphere.
As more and more heat is trapped, the average temperature of earth rises. This is the
greenhouse effect. Be sure to make it clear that this is precisely what has happened in their
miniature earth experiment:
Materials List
Each group will need:
A tank
Sand
Gravel
Foliage
Thermometer
Stopwatch
Heat lamp (one for every 2 groups to share)
Aluminum foil
Vinegar
Baking Soda
To share with the entire class:
N/A
Safety Issues:
The only safety issue here is the heat lamps. The lamps used in this lesson were rated at 75
watts; however stronger lamps are available on the market. Students should be cautious
when maneuvering and interacting with their tank under the heat lamps as direct contact
may incur burns.
Lesson Closure:
Now to provide the students with another more animated explanation and to get them
thinking about possible ways to combat global warming, continue with a short video
entitled None Like It Hot courtesy of An Inconventient Truth: A Global Warning and
Futurama. The film explains the greenhouse effect and global warming in a comical light
and offers a solution to combat warming by dropping giant ice cubes into the ocean. Now
this idea certainly is not very practical so the students are now instructed to work with
their groups to think of some steps that can be taken to reduce greenhouse gas production.
For instance, cows produce a majority of the methane coming from animals, so reduce
consumption of beef would also reduce the demand and ultimately the cow population
thereby reducing methane emissions.
One approach to reduce methane.
After sharing their ideas, discussion continues to inform students that greenhouse gases
are not completely detrimental. Had it not been for greenhouse gases Earth would be as
cold as Mars. So it should be made clear greenhouse gases in moderation are acceptable
and in excess they lead to accelerated heating of Earth which could result in rising seas,
melting ice caps and several other disasters.
Assessment:
Pre-Activity Assessment:
The lesson begins by announcing today’s lab involves greenhouse gases and asks the
students to share what they currently know about the subject and in what context have
they heard the phrase “greenhouse gas”. Some will be quick to point out global warming.
Activity Embedded Assessment:
In circulation, discuss with students the data they are currently finding and how it agrees
with their hypothesis for a given case. If there is little agreement, perhaps their intuition
was incorrect, guide them in formulating a new hypothesis or understanding of what is
occurring in their tank environment based on the data they have collected thus far.
Post-Activity Assessment:
By now students have an understanding of what greenhouse gases are, what their effects
are, by what means some of the gases are produced and how excessive gases in the
atmosphere may prove detrimental. Having the students come up with novel ideas to
reduce gas emissions demonstrates that understanding and how simple changes in their
lifestyles may have a lasting impact on their quality of life.
Is this lesson based upon or modified from existing materials? If yes, please specify
source(s) and explain how related:
This lab is based on the Greenhouse Gas Labs listed at:
http://www.umsl.edu/~biofuels/Greenhousegas.html
References:
University of Missouri, St. Louis. “Greenhouse Gas Labs.” Web. 7 March 2012.
http://www.umsl.edu/~biofuels/Greenhousegas.html
An Inconvenient Truth: A Global Warning. Dir. Davis Guggenheim. Perf. Al Gore. Paramount
2006.
“Crimes of the Hot.” Futurama. Fox. 10 November 2002.
Attachments:
 Greenhouse lab worksheet (Word)
 Greenhouse presentation (PowerPoint)
 Greenhouse presentation 2 (PowerPoint)
 None Like It Hot video (wmv)
List CA Science Standards addressed:
1. Environmental Science