Lab 3: Carbon-Life as a Greenhouse GasThe lab activity described here was developed by Candace Dunlap of TERC for the EarthLabs project.
Use the button at the right to navigate to the student activity pages for this lab. To open the student pages in a new tab or window, right-click (control-click on a Mac) the "Open the Student Activity" button and choose "Open Link in New Window" or "Open Link in New Tab."
Investigation Summary and Learning Objectives
Students use an animation, charts, and a short video to learn the basics of greenhouse chemistry, including what carbon compounds exist in the atmosphere and their relationship to the greenhouse effect. Students then compare historical ice core carbon dioxide and marine sediments temperature data to establish the relationship between global temperatures and atmospheric carbon dioxide levels. Finally, they analyze graphics of global and U.S carbon emissions to identify types and sources of carbon dioxide and watch a video about how satellite technology is used to track carbon fluxes over the United States.
After completing this investigation, students will be able to:
- Identify the important greenhouse gases and describe the role of greenhouse gases in warming the atmosphere.
- Describe how ice core data and other historical CO2 and temperature data reveal the relationship between atmospheric carbon dioxide and global temperature.
- Identify types and sources of carbon dioxide emissions in the United States and the World.
For more information about the TOPIC, read the section titled Background Information under Additional Resources below
In Part A: Students use an animation, charts, and a short video to learn the basics of greenhouse gas chemistry, including what carbon compounds exist in the atmosphere and their relationship to the greenhouse effect.
In Part B: Students use a graph and videos on historical ice core CO2 data in order to investigate the relationship between ices ages, interglacial periods and changes in CO2 levels. Students then examine more current CO2 and temperature to establish the relationship between current trends in global temperatures and atmospheric carbon dioxide levels. They use CarbonTracker, developed by NOAA, to investigate and compare atmospheric carbon dioxide time series sampled from different parts of the world.
In Part C: Students use a carbon footprint calculator developed by The Nature Conservancy. They input family household data such as family's energy usage and are then able to compare their carbon footprint with each others and with the world.
Printable MaterialsTo download one of the PDF or Word files below, right-click (control-click on a Mac) the link and choose "Save File As" or "Save Link As."
- Stop and Think Questions Labs 3A, 3B and 3C (Microsoft Word 2007 (.docx) 50kB Feb11 14)
- Suggested Answers to Stop and Think Questions Labs 3A, 3B, and 3C with answers (Microsoft Word 2007 (.docx) 111kB Feb11 14)
Teaching Notes and Tips
In Part A:
By the end of Part A, students should have constructed an understanding of the relationship between carbon dioxide and temperature of the atmosphere. They will then apply this understanding in Lab 2-B, when they analyze graphs of historical carbon dioxide data.
You may want to have a discussion about the size of the atmosphere in the first image comparing the atmospheres of Mars, Venus and the Earth. Note that the ratio of the thickness of the atmosphere size to the diameter of the three planets is exaggerated for visual effect and that it is important for students to understand that the Earth's atmosphere is not that thick in relation to the Earth's diameter. To get a sense of the thickness of the troposphere and stratosphere layers of the atmosphere, try this simple exercise. Use a compass to draw a circle with a radius of 127 mm. This circle represents the Earth and the inner-most atmosphere. The 1 mm line drawn by your pencil represents the average thickness of the first two layers of the atmosphere: the troposphere, the region of weather, and the stratosphere, which protects us from most of the Sun's harmful ultraviolet (UV) radiation.
In Part B:
As with all the graphs, you may want to spend time projecting the graphs on the board and going over the graph elements with them.
Graph: CO2, Temperature and ice ages.
Students need to spend some time analyzing the first graph on CO2, ice ages and temperatures. By asking them to look for "elements of a story" in this graph, students will start to see that the changes in atmospheric CO2 are related to changes in temperature. You may want to talk about Milankovitch cycles and ice ages depending on your classes but it is not necessary. Students simply need to see that trends in carbon dioxide seem to correlate with trends in temperature and ice ages over the past 800,00 years.
As with any graph, it might be a good idea to project this graph on the board so you can have a class discussion on what the elements of the graph are.
Some resources are included below.
The Keeling Curve:
This is an iconic historical graph so you may to talk a little bit about the history. You will need to talk about variability versus the trend of the line. The "squiggy" lines represent seasonal variations in CO2 dioxide due primarily to seasonal changes in the photosynthetic rates of deciduous forests.
Rather than give students a graph that illustrates where scientists think the CO2levels will be in the year 2100, students should be able use a variety of strategies, such as line of best fit. You may want to consider putting the Keeling Curve up on the smartboard or overhead and then ask students to carryout the discussion. They use CarbonTracker, developed by NOAA, to investigate and compare atmospheric carbon dioxide time series sampled from different parts of the world - including the Keeling Curve data from Mauna Loa. They examine carbon dioxide time series data from at least three sampling sites around the world and then describe the overall trends of CO2 at each site. When students compare their graphs from around the world, they will see both similarities (trends of rising CO2) and differences (example - some show greater variability and some less). These similarities and differences will generate some rich discussions.
In Part C:
Students explores ways to reduce their family's carbon footprint. Students may not have some of the information they need to input so teachers may need to have information ready for some "typical families" and/or work with students to make a best "guesstimate." There are many carbon footprint calculators on the web which my be more appropriate based on student age.
Student notebooks are optional. Here are just a few suggestions for what to include in student notebooks for Lab 3:
Note: You may want to separate actual data collection and analysis into a Lab Notebook.
- Drawings and notes from videos, animations and discussions
- Drawings of models and any revisions
- Notes and data from the Keeling Curve analysis.
- Notes, data and drawings from the Carbon Tracker Activity
- Notes from the Carbon Footprint activity comparing your carbon footprint with the world's average.
Assessment:There are several options for assessments of students understanding of material produced in this Lab. Teachers can choose from the following list or create their own assessments.
- Assess student understanding of topics addressed in this investigation by grading their responses to the Stop and Think questions.
- Teachers may want to assess students' analysis of their CarbonTracker activity in Lab 3B
- Written Test for Lab 3 (Microsoft Word 2007 (.docx) 118kB Jan21 14) (Answer Key (Microsoft Word 2007 (.docx) 165kB Jan21 14))
State and National Science Teaching Standards
TO BE PROVIDED LATER
Developer will correlate activity to standards listed at this site:National Science Education Standards (SRI)
Earth - The Operator's manual. Two of Richard Alley's video clips included in the LAB 3 investigation come from the Earth- The Operator's Manual website. This is truly an excellent site. You may want to consider having students watch the entire video.
Consider doing the "How Heavy is My Carbon Footprint" activity in the Content Extension section with your entire class.
Use the Greenhouse Gas Equivalencies Calculator to help you translate abstract measurements into concrete terms you can understand, such as "equivalent to avoiding the carbon dioxide emissions of 183,000 cars annually."