Students explore
the effects of
thermal expansion
on sea levels—both
globally and close
to home
E
Molly Trendell Nation,
Allan Feldman, and
Ping Wang
arth’s climate is rapidly changing as the concentration
of atmospheric greenhouse gases increases. These heattrapping gases, data shows, raise global temperatures.
The last decade was the warmest on record, and average temperatures have continued to rise (UCAR 2015). Students, as
members of society, need a clear understanding of climate
change, how it affects the Earth, and the science behind it.
34
The Science Teacher
Place-based education
F IGUR E 1
The effects of global warming have been publicly communicated in many ways, often with images of melting polar
ice and stranded polar bears. While these images may arouse
sympathy, their settings are distant from the daily experience
of most of the world’s populace. A place-based approach may
be more effective in teaching the public—and science students—about climate change science.
Placed-based education grounds learning to the specific
region in which the learning takes place (Smith 2002). This
approach can allow students to connect to their community
within the context of the classroom activity. Collaborating
with classmates to explore local, real-life problems, students
can develop a stake in contributing to the betterment of their
community and neighborhoods (Smith 2007).
Sea-level rise is a significant problem for those living near
the coasts. In Florida, the authors’ home state, 75% of residents live at or near sea level. Clearly, Florida students, to
be informed citizens, need climate change education in their
secondary science curriculum. Campbell et al. (2010) found
that teachers wish to teach climate change science but often
don’t know where or how to include it in their curriculum. A
possible solution is for scientists and educators to collaborate
on a curriculum that addresses climate change (Campbell et
al. 2010; Gayford 2002).
With funding from the National Science Foundation and
collaboration between scientists and science educators, we have
developed place-based curriculum materials that use scientific
data and hands-on activities to help students understand how
climate change affects their communities and their lives.
Close-up of flask neck showing
marks made as the water level rose
with increasing temperature.
Thermal expansion classroom activity
We developed an activity for high school teachers and students
in marine sciences classes in the Tampa Bay area, a low-lying
coastal region of west central Florida comprising Hillsborough, Pinellas, and Manatee counties. Tourism along the Gulf
beaches is a major source of area income. With most of Florida’s
coastline at or below 3.5 meters in elevation, the Tampa Bay
area faces the daunting task of preparing for future sea-level
rise caused by global climate change (GCC) (TBRPC 2006).
One of the largest contributors to sea-level rise is the thermal expansion of ocean water due to Earth’s rising temperature (USGCRP 2009; IPCC 2013). Students can measure the
rate of expansion of water as it warms and calculate how this
expansion relates to rising sea levels.
Learning objectives
The goal of this activity is for students to
better understand the effects of climate
change on the built and natural world,
particularly in south Florida. The
activity also attempts to motivate
students to learn about regional
issues (Hallar, McCubbin, and Wright 2011; Theobald 2006).
This activity aligns with the Next Generation Science Standards (NGSS Lead States 2013) (see box, p. 36).
Other objectives:
◆◆
◆◆
◆◆
Students learn the relationships between the temperature
of water and its volume and between ocean temperature
change and changes in sea level.
Students use a laboratory activity to model the effect of
global warming on sea-level rise.
Students gain an appreciation of why thermal expansion
is a concern for them in their local area.
Background preparation
Before the activity, students learn what is meant by global
mean sea level and how it is measured and has changed over
time and the causes of sea-level change. This information is
delivered via a PowerPoint presentation, brief videos, and a
hands-on activity in which students make a simple sea-level
gauge from a gallon milk jug. (Background information,
September 2015
35
Connecting to the Next Generation Science Standards (NGSS Lead States 2013).
The materials/lessons/activities outlined in this article are just one step toward reaching the performance expectations listed
below.
Standards
HS-ESS2 Earth’s Systems
HS-ESS3 Earth and Human Activity
Performance Expectations
HS-ESS2-4. Use a model to describe how variations in the flow of energy into and out of Earth’s systems result in changes in
climate.
HS-ESS3-1. Construct an explanation based on evidence for how the availability of natural resources, occurrence of natural
hazards, and changes in climate have influenced human activity.
HS-ESS3-5. Analyze geoscience data and the results from global climate models to make an evidence-based forecast of the
current rate of global or regional climate change and associated future impacts to Earth systems.
Dimension
Name or NGSS code/citation
Specific connections to the classroom activity
Science and
Engineering
Practices
Developing and Using Models
Students work with empirical data collected from the
thermal expansion activity to model and explain the
rise in water level and generate predictions about the
phenomenon of future sea-level rise of our oceans.
Analyzing and Interpreting Data
Students take evidence and data collected from the
thermal expansion activity and the water level in
the flask to use in developing credible evidence that
supports sea-level rise as it relates to climate change.
Disciplinary
Core Ideas
ESS2.D: Weather and Climate
• Changes in the atmosphere due to human
activity have increased carbon dioxide
concentrations and thus affect climate.
ESS3.D: Global Climate Change
• Though the magnitudes of human impacts are
greater than they have ever been, so too are
human abilities to model, predict, and manage
current and future impacts.
ESS2.A: Earth Materials and Systems
• The geological record shows that changes
to global and regional climate can be caused
by interactions among changes in the sun’s
energy output or Earth’s orbit, tectonic events,
ocean circulation, volcanic activity, glaciers,
vegetation, and human activities.
Crosscutting
Concepts
Cause and Effect
Empirical evidence is required to differentiate
between cause and correlation and make claims
about specific causes and effects.
Stability and Change
Change and rates of change can be quantified and
modeled over very short or very long periods of
time. Some system changes are irreversible.
36
The Science Teacher
Follow-up question from the lab activity: What personal
actions can you take to take to slow the threat of sealevel rise?
Follow-up question from the lab activity: Based on the
observed change in water level in the flask during the
thermal expansion lab, how do you think global warming
will contribute to sea-level rise in our oceans?
Students use the interactive website “A Student’s Guide
to Global Climate Change” (http://1.usa.gov/1CcYrFl),
where they watch videos about sea-level rise and answer questions related to the content.
Student use the data they collected in the activity to
generate a graph that shows the relationship between
increased temperature and volume in the flask.
Students observe change of volume of water in flask
over a short time (~20 minutes). Students then use
these data to model the changes in sea level over the
next century and compare their predictions to the IPCC
report findings.
A Rising Tide
details about the laboratory setup, related materials, and questions for students are available online [see “On the web”].)
Laboratory setup
The necessary lab equipment includes:
◆◆
hot plate
◆◆
Florence flask (or an Erlenmeyer flask)
◆◆
thermometer
◆◆
two-hole rubber stopper
◆◆
graduated cylinder
◆◆
pipette, fine-tip marker.
Steps
Students fill the flask with tap water to a point on the lower
part of neck above where it narrows to become cylindrical.
FI G U R E 2
Laboratory setup, showing the
flask and hot plate with a digital
thermometer.
The thermometer is carefully inserted into one of the holes
of the rubber stopper. Safety note: This step should be performed in advance and only by a trained teacher. Lubricate
the thermometer with water or silicone grease and insert the
thermometer cautiously, use a towel (or heavy gloves that are
coated for rough or sharp materials) to protect your hands,
and wear safety glasses. (Alternatively, a digital temperature
probe can be used [Figure 2].) Students then insert the stopper into the flask.
Students use the marker to mark the water level of this
initial volume of water in the flask.
Students place the flask on the hot plate, turn on the heating element, and, as the water warms, mark the neck of the
flask at the water level for every 10°C increase in water temperature, stopping data collection when the water temperature reaches 95°C (Figure 1, p. 35, and Figure 3), which is
below the boiling point.
The next day, after the water cools, students measure the
increase in water volume for each mark on the flask’s neck.
The volume can be measured by refilling the flask with tap
water to the initial volume mark and then adding measured
amounts of water via pipette to each of the marks on the
neck. Alternatively, the students can use a 10 ml graduated
cylinder to measure how much water they need to increase
the level to the next mark. The amount of water added to
reach each mark on the neck indicates the increase in volume
of water per 10°C. Sample data are in Figure 3.
Safety note: When heating the flask, be sure to use a twohole stopper to prevent a dangerous buildup of pressure (the
thermometer occupies one hole in the stopper, and the other
hole serves as a vent). Do not heat the water above 95°C.
During the activity, students should wear chemical-splash
goggles and heat-protective gloves.
F IGUR E 3
Data collected in the activity.
Change in T
(oC)
Total Change
in volume (ml)
Total volume
(ml)
0
0.0
542.0
10
1.4
543.4
20
3.0
545.0
30
4.5
546.5
40
5.8
549.2
50
7.8
549.8
60
8.9
550.9
70
10.2
553.6
80
11.6
553.6
September 2015
37
Analyzing and interpreting data
F IGUR E 4
Students use data gathered during this activity to generate a
graph plotting the relationship between water temperature
and volume (Figure 4). Although the thermal expansion of
water is nonlinear from 0 to 100°C (Figure 5), the curve is
fairly straight above 20°C, which is where most of the student data is collected. Students analyze their data and graphs
to determine the rate of volume change associated with temperature rise. Using the data and graphs along with information about the volume and area of the oceans (Figure 6),
students do a set of calculations to predict the rise of sea level
due to thermal expansion per °C (Figure 7).
Because most ocean warming occurs in the top 1,000 m of
water (ICCP 2013), rather than using the average depth of
the oceans, we use 1,000 m to calculate ocean volumes (read
online about how the thermocline [the layer of ocean water
where the temperature changes more rapidly than in the
warmer layer above or the colder layer below] affects ocean
warming; see “On the web”). Analysis of our pilot data in this
example predicts a 0.28 m sea level rise per one-degree Celsius temperature rise in the top 1,000 m of the ocean. This is
within the values predicted by the models used by the Intergovernmental Panel on Climate Change (IPCC) in their 2013
report. This activity, though developed for the Tampa Bay
region, can be used anywhere with the information about
other oceans provided in Figure 6.
Next, we ask students follow-up questions about the consequences of sea level rise in areas they frequent, such as the
Gulf beaches and Tampa Bay. They also compare their predictions with IPCC’s prediction for future sea-level rise. We
encourage students to think about social and environmental factors that would affect the region based on their data
and predictions. Lastly, we ask students to suggest ways that
they, as individuals, could help mitigate the effects of climate
Graph of the change in volume of water
in the flask vs. change in temperature.
F IGUR E 5
Graph of accepted values for the
thermal expansion of water.
FI G U R E 6
The areas, volumes, and depths of the oceans.
Ocean
Area (km2)
Volume (km3)
Maximum
Depth (m)
Average
Depth (m)
Volume most
affected by GCC (km3)
Arctic
15,558,000
18,750,000
5567
1205
15,558,000
Atlantic
85,133,000
310,410,900
8486
3646
85,133,000
Indian
70,560,000
264,000,000
7906
3741
70,560,000
Pacific
161,760,000
660,000,000
10803
4080
161,760,000
Information from Eakins and Sharman (2010) and IPCC (2013). The volume of the ocean most affected by Global Climate
Change (GCC) is calculated by multiplying the ocean’s area by 1,000 m, the top ocean layer most affected by GCC.
38
The Science Teacher
A Rising Tide
F IGU R E 7
Calculations for estimating the rise in sea level due to thermal expansion of the oceans.
Students can estimate the sea-level rise due to thermal expansion using the data that they collected in this activity. There
are several steps and each is illustrated using the data from Figures 3 and 4.
1. First, calculate the slope of the graph to find the increase in volume per degree Celsius in their flask.
ΔV
Slope = ΔT
8.0ml - 0.0 ml
Slope =
o
o
55 C - 0.0 C
Slope = 0.145ml/oC = 0.15 ml/oC
2. Next, find the ratio of the increase in volume of any body of water (DV) to the increase in temperature by dividing the
slope for the flask by the initial volume of water in the flask.
Slope
ΔV =
ΔT Initial Volume
o
ΔV = 0.15 ml/ C
ΔT
542 ml
ΔV = 0.00028/ oC
ΔT
3. Use the ratio found in step 2 and the data in Figure 6 to find how much the volume of the top 1,000 m (1.0 km) of one
of the oceans would increase due to thermal expansion
DV of an ocean per °C = (V of an ocean most affected by GCC) x ΔV
ΔT
DV of the Atlantic Ocean per °C = 85,133,000 km x 0.00028/°C
3
DV of the Atlantic Ocean per °C = 24,000 km3/°C
4. Finally, calculate the sea level rise per degree Celsius by dividing the increase in volume of an ocean per by the area of
the ocean.
o
Sea level rise per °C of an ocean = ΔV of an ocean per C
Area of the ocean
3 o
D h of the Atlantic Ocean per °C = 24,000 km / C
85,133,000 km2
D h of the Atlantic Ocean per °C = 0.00028 km/°C
D h of the Atlantic Ocean per °C = 0.28 m per °C
Note: It may seem that Steps 3 and 4 are unnecessary because we are multiplying and dividing by the same value. However,
in Step 3 we are multiplying by the volume of the ocean most affected by temperature changes, which is measured in km3,
while in Step 4 we are dividing by area of the ocean, which is measured in km2.
September 2015
39
A Rising Tide
change on low-lying coastal regions such as ours.
To help with the latter, we direct students to the Surging
Seas website (see “On the web”) to review experts’ predictions, forecasts, and reports related to sea-level rise throughout the country and specifically in the Tampa Bay area. This
website, as well as others such as the Coastal Flood Exposure
Mapper (see “On the web”), allow students to see the effects
of sea-level rise on their localities.
Conclusion
Global climate change and its effects are real and immediate.
Students must gain an understanding of climate science so
they can participate in public debate about how to reduce the
emission of heat-trapping gases and how their communities
can mitigate the effects of global warming. In this activity,
students model these effects on Earth’s oceans and predict
sea-level rise due to thermal expansion. They then compare
their predictions with those of IPCC scientists and see how
a simple laboratory activity can model global phenomena.
In addition, this investigation allows students to make realworld connections about sea-level rise in a place-based setting, make predictions about the future for coastal regions,
and engage in authentic collaborative science practices. ■
Molly Trendell Nation (mollynation@mail.usf.edu) is a graduate
research assistant in the science education PhD program; Allan
Feldman (afeldman@usf.edu) is a professor of science education;
and Ping Wang (pwang@usf.edu) is a professor of geosciences at
the University of South Florida in Tampa.
Acknowledgment
The curriculum project described in this article was developed
with funding from the National Science Foundation (DRL1316782).
On the web
Coastal Flood Exposure Mapper: www.coast.noaa.gov/floodexposure
How the thermocline affects ocean warming:
http://marinebio.org/oceans/temperature
Supplementary materials for this activity: http://bit.ly/CHANGEUSF
Surging Seas: http://sealevel.climatecentral.org
40
The Science Teacher
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