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The Complexity of Global Warming
Student Introduction Sheet
PA Standards:
3.1.7/10/12.B,E Describe the use of models as an application of scientific or technological concepts.
Apply concepts of models as a method to predict and understand science and
technology. Identify change as a variable in describing natural and physical
systems. Describe patterns of change in nature, physical and manmade systems.
3.2.7/10/12.B
Evaluate experimental information for appropriateness and adherence to relevant
science processes.
3.5.10/12.C
Interpret meteorological data – describe weather and climate patterns on global
levels.
Analyze atmospheric energy transfers – that occur during the greenhouse effect and
predict the long-term effects of increased pollutant levels in the atmosphere.
4.8.7/10.C
Explain how human activities may affect local, regional and national environments.
Describe what effect consumption and related generation of wastes have on the
environment.
4.8.12. D
Analyze the international implications of environmental occurrences.
Introduction:
Global warming is a phenomenon that affects all of the world’s 6+ billion inhabitants (not to
mention all other organisms that live on the planet earth). Global warming, by definition, leads to an
average increase in the temperature of the atmosphere; however it can locally lead to warmer OR
colder than average temperatures.
For decades, computer models have attempted to predict how much the earth’s atmosphere
will warm and weather patterns change as a result of global warming, but programmers and scientists
have been continually frustrated by their models. The factors that contribute to global warming are so
complex and interrelated that no model has yet been entirely successful. Each subsequent model
becomes more complex than the last and can better predict the future of global warming, but no
model to date has included every factor (some factors may not even be known).
Vocabulary:
AlbedoSolar OutputGreen House EffectGlobal WarmingInsolationGuiding questions:
Is the planet getting warmer?
What would a warmer earth be like?
How will an increase in atmospheric water vapor change the atmospheric temperature?
How does an increase in cloud cover affect atmospheric temperature?
How will a change in solar output affect the warming of the atmosphere?
How does a change in land albedo affect the temperature of the atmosphere?
How does an increase in CO2 levels affect warming of the atmosphere?
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Common Materials: (One set necessary for each lab, 5 sets total)
 1 Computer
 LabPro Interface
 1-2 Stainless Steel Temperature Probes (See individual procedures)
 2 250 mL Erlenmeyer flasks and rubber 1-hole stoppers
 1 Ruler or Spacing Board
 1 Flask Stand
 ~100 mL Small Grain Black Gravel
 1 Work Light with a 250 Watt setting
 Safety Goggles
 Room Temperature Water
Experiment-Specific Materials:
Water Vapor Experiment: Spray Bottle
Cloud Cover Experiment: Artificial Window Frosting
Solar Output Experiment: 1 work light with 250 Watt/ 500 Watt dual setting.
Albedo Experiment: ~50 mL Tan Gravel
CO2 Experiment: 2 Rubber or Glass Tube Connectors
1 Alka-Seltzer Tablet
1 2-hole rubber stopper for Erlenmeyer flask
Procedure:
There will be five stations in the classroom. At each station, there will be a labeled box of
equipment for one of the environmental factors being tested. There will also be a computer, LabPro,
USB cable, and power adaptor for the LabPro.
Student will be divided into 5 groups. The groups can rotate through all the stations or they
can just do one each and report to the group. Also, there is the option of doing the individual labs
twice and getting an average. When a group starts a station, they should watch the video for that
station and then follow the written procedure to complete the lab. There are two pages to the menu
page of the video instructions. You must click on the arrow at the bottom of the screen to change
pages.
Safety:
Work lights and light bulbs get hot. Use care when handling. Wear safety glasses at all times.
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The Complexity of Global Warming
Teacher Notes
Lab Time: Labs vary in set-up and execution times. But a 45 minute class period is a sufficient
amount of time in which to set up, perform and discuss one lab per group.
Grade Level: 6-12, environmental, life, biology, general science, chemistry
Objectives:
Determine how changes in atmospheric CO2 levels change atmospheric temperature.
Determine how changes in reflectance of sunlight change atmospheric temperature.
Determine how changes in land albedo (reflectivity) change atmospheric temperature.
Determine how changes in atmospheric water vapor levels change atmospheric temperature.
Determine how changes in solar output change atmospheric temperature.
Due to its complexity, this lab is not recommended for a first time use of LoggerPro, unless there are
no time constraints on the lab period. Students could be introduced to the software with one of
Advancing Science’s less complicated activities. (Contact AS for details and suggestions.)
The lab can be done in different ways, depending on the inclination of the teacher and the time you
have to spend. Factors could be assigned to groups, students could choose what to test, each group
could investigate all the factors, etc. A follow up day of discussion is advised to talk about results.
Time Management:
This lab is variable in that it can be adjusted to be performed in one 45 minute class period, during
multiple periods, or for each lab to be showcased separately throughout the school year and
integrated into lecture and class discussion. Below are sample schedules designed to utilize the lab
over different periods of time.
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One 45 minute class period: Prior to the class period, the instructor should put the materials
out for each lab station. This would be the box for that station, a computer, LabPro and power
adapter, and USB cable. Students will split into five groups of at least two students each, and
every group will be assigned one lab to complete. Each group will watch a short instructional
video before beginning their lab. In order to acquire a full set of data, students should write
their findings on the blackboard, and complete Data Table 1 and Data Table 2 in class. The
class should reconvene and discuss the implications of the lab findings. Discussion questions
should be answered for homework, or in class if time permits.
Three to Four 45 minute class periods:
Day One: Prior to the class period, the instructor should set up each lab station with the box
for that station, a computer, LabPro and power adapter, and USB cable. Students will split
into five groups of at least two students each, and every group will be assigned one lab to
complete. Upon completion of the lab, students will enter their findings into Data Table 1 &
2 and complete discussion questions as time permits or as homework.
Day Two: Prior to the class period, the instructor should set up each lab station. Students
should strive to complete two labs and enter their findings into Data Table 1 & 2 and
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complete discussion questions as time permits or as homework.
Day Three: Day Three should be conducted largely the same as Day Two. If no fourth day is
planned, the students should discuss and compare their findings toward the end of class.
Day Four: If a fourth day is planned, students should compare their data as a class. The
students’ data for each individual lab should be averaged in order to determine a class
average, which should allow more reliable data for observation. Together, the class should
address the discussion questions and discuss the implications of climate change.
For Longer Classes: Because some schools offer block scheduling or extended lab periods,
it is possible to adjust the extended schedule to fit into fewer days. Longer class periods will
also allow for longer, more in-depth discussion of climate change and how the labs reflect the
workings of the environment.
Lab Results:
CO2:
Expect a rise in temperature after the alka-seltzer is introduced into the flask. The alka-seltzer
represents carbon dioxide and to support the global warming theory it must rise. Multiple
experiments have produced results varying from an increase of .5° to an increase of 3°.
Surface Albedo:
The temperature probe in the gravel represents the amount of radiation from the lamp being absorbed
by the black gravel and reflected by the white gravel. Higher temperature readings should depict a
low albedo with the gravel absorbing radiation, while lower temperatures should replicate high
albedo as solar radiation is reflected away by the gravel.
Cloud Cover:
The results of the experiment should show that the flask without the artificial snow’s temperature
rises at a much more rapid pace than the flask with the artificial snow.
Water Vapor:
Ideally, the flask without water vapor will rise more quickly for the first 90 seconds, as the flask
containing water vapor has a tendency to remain cooler initially. When an insufficient level of water
is sprayed in the flask, it occasionally heats up faster than the empty flask. After the 90 second
period, the water vapor flask should remain warmer than the empty flask, as water vapor is a
greenhouse gas and traps heat.
Solar Output:
The temperature probe in the black gravel should absorb more solar radiation throughout the duration
of the test trial. The two different lamp settings represent a change the energy output from the sun,
with a lower output in the first test trial and a higher output for the second part. It should be expected
that the temperature readings will be greater with a increased energy output from the Sun.
Troubleshooting:
 For the cloud cover experiment, tracing paper may be used in lieu of artificial window
frosting if it is not available. Make sure to provide adequate layers of paper to allow some
light penetration, but not a significant amount. By increasing the amount of artificial window
frosting or tracing paper on the ‘cloudy’ flask, better results may be obtained if issues occur
at first.
 For the water vapor experiment, better results can be obtained by making sure that sufficient
water is sprayed into the flask. If not enough water is used, results may not appear as
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concrete. Additionally, any tool that will allow for a finer mist of water being sprayed into
the flask (such as a perfume decanter) may be used if available.
For the albedo experiment, ensuring that both the black and tan gravel are of similar, if not
uniform grain size may better the results of the experiment.
Major Concepts:
Students must understand graph interpretation and the concept of slope. This experiment
complements numerous curriculum areas. The obvious fit would be in an Environmental Science
class when studying global warming and the greenhouse effect. The lab can also be done in biology
when studying anything environmental. It could be used in Chemistry when studying kinetic
molecular theory and gases. It could be used in Earth Science or General Science when learning
about meteorology and climate.
This lab and topic cannot be performed without discussing the political cloud surrounding it. It is also
a good place to show students that not all scientists agree on the interpretation of the same data. It
can also be used to generate an interesting discussion on ethics in science.
Vocabulary List:
Albedo- The fraction of the total light striking a surface that gets reflected from that surface. An
object that has a high albedo (near 1) is very bright; an object that has a low albedo (near 0) is dark.
The Earth's albedo is about 0.37. The Moon's is about 0.12.
Insolation- The solar radiation striking a given surface. In(coming) so(lar radi)ation.
Solar Output- The overall strength and intensity of the sun’s radiation.
Greenhouse Effect- The phenomenon whereby the earth's atmosphere traps solar radiation, caused by
the presence in the atmosphere of gases such as carbon dioxide, water vapor, and methane that
allow incoming sunlight to pass through but absorb heat radiated back from the earth's surface.
Global Warming- an increase in the earth's average atmospheric temperature that causes
corresponding changes in climate and that may result from the greenhouse effects
Question Answers:
1. What happened when the alka-seltzer was added to the second flask? The tablet
started to dissolve and react with the water and bubbles of carbon dioxide were released.
2. Do your results agree with the accepted theory about the effect of CO2 on the
environment? There is some increase in temperature which does correspond with the
idea that carbon dioxide in the atmosphere is a greenhouse gas and does absorb solar
energy and raise atmospheric temperatures.
3. What do you predict will happen with the world’s carbon dioxide level in the future
and what effect do you predict that will have on the world’s climate? In the near
future, carbon dioxide levels will almost certainly go up. With more people in the world
buying cars and consuming more energy, the levels would go up. If we work to restrict
carbon dioxide levels, we will probably only slow the increase. In the future we may
develop forms of energy production that are not hydrocarbon based and the levels may go
down. Since the data indicates that increased carbon dioxide increases the temperature,
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we can assume that the atmospheric temperatures should go up in the near future.
Surface Albedo and its Effect on Atmospheric Temperature
1. Give an example of how a change in albedo could impact atmospheric temperature.
Is this consistent with the results from your experiment? Many examples could be
given. Cities with their large paved areas have temperatures that are consistently higher
than surrounding areas. This would be consistent with the results from the lab where the
black gravel heated up more than the white.
2. Based on what you already know from global warming, do your results make sense?
Why or why not. We do know that more of the planet is being paved. We also have
been told that the reflective ice caps are melting.
.
3. Based on your results today, do you think albedo could affect ocean temperatures?
If the atmosphere did warm, that in turn would increase ocean temperatures.
Cloud Cover Changes and its Effect on Atmospheric Temperature
1. Did this experiment demonstrate the ability of clouds to reflect heat and keep it out,
or did it demonstrate the ability of clouds to act as insulation and keep heat in?
Was this consistent with what you expected? This experiment demonstrated the ability
of clouds to reflect heat. Clouds also do act as insulators but, in this case, the lab just
showed the one characteristic.
2. How might increased temperatures caused by climate change magnify the effects of
clouds? If the global climate warmed this could cause more evaporation of water and
therefore more clouds. More clouds could reflect more solar energy but they would also
trap more heat so there would be a mixed effect.
Water Vapor Increase and its Effect on Atmospheric Temperature
1. From 0 to 90 seconds, which flask heated up faster? Why do you think this
happened? How does this reflect how water vapor in the atmosphere controls
temperature? The temperature increased quicker in the flask without the water. This
happened because water has a high heat capacity. It takes a lot of energy to heat it up.
Areas on the planet that are dry such as deserts heat up quickly during the day. Areas on
the planet with near oceans or with humid atmospheres have slower increases in
temperature.
2. From 90 to 270 seconds, which flask cooled down faster? Why do you think that is?
How does this reflect how water vapor in the atmosphere controls temperature?
The dry flask cooled down faster. This is again because of the high heat capacity of
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water. Once it is heated, it retains that heat. Overnight the desert cools down quickly,
but on a tropical island, the temperatures drop very slowly at night.
Solar Output Changes and its Effect on Atmospheric Temperature
1. What connection did you see between the amount of solar output and temperature
change? More solar output means increased temperatures.
2. Does solar output vary? Has it changed in the past? Solar output does vary. Usually
not a lot from year to year but there is some variation. We have only been able to directly
measure solar output using satellites since the late 1970’s. It appears that solar activity
follows a general 11 year cycle. Measurements show that there is a vary small variation in
solar output during the cycle(roughly 0.1 percent of the 1,366 watts per square meter
received at the top of the atmosphere, for approximately 0.12 watt per square meter).
However, indirect measures of solar output are available from historical sunspot
measurements dating back through the early 17th century. Using this and other longer
term data, it appears there are also non-periodic changes in solar output. Besides solar
output, other important factors in how much solar energy actually reaches the earth are
variations in the orbit of the earth and the tilt of the earth’s rotational axis. These two
topics could have a major effect how much solar energy actually reaches the earth and
where that energy is concentrated.
3. If increased solar output was a problem, is there anything that could be done about
it? At present we have no way to affect the output of the sun but we could possibly use
techniques to block some solar energy from reaching the earth. Some scientists have
proposed using large space arrays of reflective material to block some solar energy.
The Complexity of Global Warming was written by Jeremy J. Kuhar and adapted by Valerie Stone and Jack Sipe
(Gettysburg College) for the Advancing Science Program at Gettysburg College, Gettysburg, PA 17325
http://www.advancingscience.org Teacher notes were suggested by Karen Albert of York Suburban Middle School,
York PA. This version was adapted at Ursinus College, Collegeville, PA 19426 by the Fall ’08 semester Global
Climate Change Class (Dr. Leah Joseph, Kyle Shelton, Jen Tepel, Rebecca Lamhut, Jesse T. Jones, Jenna Rorer,
Sara Simon, Meg Dawley, Davis Howley and Jon Roth) and Ursinus Mobile Educator, Ron Faust for use by the
Science in Motion program at Ursinus College.
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