Lab 2:The Carbon Cycle-What Goes Around Comes Around

The 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 focus initially on a sub-section of Earth's natural carbon cycle related to the biosphere involving the cycling of carbon through the processes of photosynthesis, respiration, and decay. Following that, they study an annotated representation of the full carbon cycle with reservoirs and the processes that drive carbon from one reservoir to others. Finally, students learn about the interconnectedness of the Earth system, feedback loops, and how changes in the carbon cycle lead to other changes in the system.

After completing this investigation, students will be able to:

• Describe how the primary biosphere processes of photosynthesis, cell respiration, decomposition and combustion move carbon atoms between the geosphere (atmosphere, lithosphere, hydrosphere) and the biosphere.
• Identify the four major carbon reservoirs and explain how carbon moves from one reservoir to another.
• Provide examples of the various time scales at which carbon cycles through the Earth System's spheres.
• Describe the effects of negative and positive feedback on the carbon cycle in a western U.S. forest ecosystem that has been disrupted by a pine bark beetle infestation.
  

For more information about the TOPIC, read the section titled Background Information under Additional Resources below

Activity Overview

In Part A: Students take on the role of a carbon atom moving through the various reservoirs in a lodgepole pine forest ecosystem. They explore the various carbon cycle processes (example: photosynthesis, respiration, decay, ingestions etc) that move carbon from one reservoir to another. Some of these processes take place in a fraction of a second while others can take millions of years.

In Part B: Students get a broader introduction to the carbon cycle by using an interactive visualization that highlights the major carbon reservoirs and processes in the larger, more complex global carbon cycle. They are able to see that the time scales of geosphere processes (thousands to millions of years) are much longer than time scales of biosphere processes.

In Part C: Students are introduced to the positive and negative feedback loops that play a critical role in either amplifying or damping change in the Earth system.

Printable Materials

To 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."

• Lodgepole Pine Carbon Cycle Station Posters (Microsoft Word 2007 (.docx) 19.1MB Mar30 15)
• Lodgepole Pine Carbon Cycle Tickets (Microsoft Word 2007 (.docx) 106kB Mar30 15)
• Lodgepole Pine Carbon Cycle Passport Chart (Acrobat (PDF) 57kB Mar30 15)
• Lodgepole Pine Carbon Cycle Game Instructions (Acrobat (PDF) 237kB Mar30 15)
  

• Stop and Think Questions -- educator-only file
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  Stop and Think Questions

  
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  Note: There are no Stop and Think questions for Part B.
  
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  for Stop and Think Questions.

Teaching Notes and Tips

Part A: Follow the instructions on how to set up the forest carbon cycle stations at this link. Forest Carbon Cycle Instructions. Note: If you have AP students, you may want to skip this lesson and proceed directly to Lab 2B.

Part B: Students will need access to the carbon cycle interactive to do this activity. In the Carbon Journey activity in Part B, you may want to consider assigning groups specific starting points so groups don't chose the easier ones.

Each group must describe two carbon pathways - one from a shorter time scale and the other from a longer. One of these pathways must include the ocean reservoir.

Students' flow charts can be fairly simple or they might want to enhance them with drawings and images. You may want to consider having students describe "how much carbon" is in each reservoir not only in metric gigatonnes, but also in number of school buses as described below.

Students' misconceptions and naive understandings to be aware of for this activity are:
1. Carbon is destroyed when fossil fuels are burned.
2. The carbon cycle consists of only photosynthesis and respiration.
3. Fossil Fuels have been around since the origins of the Earth.
4. Fossil Fuels are made from dead dinosaurs.

Part C: Students are asked to begin thinking about connections between the carbon cycle and climate change and global temperature. The element strips are provided as scaffolding for this activity. If you have advanced students, you may want to consider not giving students the element strips and instead, have students read the provided resources and identify the elements of the Pine Bark Beetle and climate story.

Student Notebooks

Student notebooks are optional. Here are just a few suggestions for what to include in student notebooks for Lab 2:

• Drawings - Carbon Journey drawings from Lab 2B
  
• Drawings of Connection Circles and feedback loops in Lab 2C
• Drawings of models and any revisions
  
• Notes from videos and discussions
  

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.

National Science Teaching Standards

Lab 2 supports the following Next Generation Science Standards (NGSS):

Science and Engineering Practices

2. Developing and Using Models

Disciplinary Core Ideas

ESS2.A Earth's Materials and Systems

ESS2.E Biogeology

LS2.A Ecosystem Functioning Dynamics and Resilience

Cross-Cutting Concepts

2. Cause and effect

3. Scale, Proportion and Quantity

4. Systems and System Models

5. Energy and Matter

7. Stability and Change

Additional Resources

Background Information

The first two links provide excellent background information on the carbon cycle. The third link, 'What Carbon Cycle,' reports on students misconceptions. The fourth link brings you to Dr. David Archer's lectures on The Carbon Cycle on YouTube. Dr. Archer is an expert on the Carbon Cycle. The lecture for chapter 8 - The Lungs of the Carbon Cycle - is especially relevant and interesting.
Carbon Cycle
Carbon Cycle Background
What Carbon Cycle?

David Archer's University of Chicago lectures on The Carbon Cycle
The Pine Bark Beetle Blues

Content Extension:

Have students use animation software or animation apps to animate their feedback loop.