Educator Guide - Ecosystems and Carbon

Summary and Learning Objectives

Students engage with twelve resources (readings, interactives, videos, modeling activities) to investigate the role of the ecosystem in cycling of carbon dioxide among the hydrosphere, atmosphere, geosphere, and biosphere. Through a series of learning experiences, students view short video clips, download, graph, model, and analyze CO2 data, and work with several interactive modeling online resources.

Essential Question

What are the primary causes of the annual fluctuations and long-term trends in the Keeling CO2 curve?

After completing this investigation, students will be able to:

  • Describe how elements of ecosystem affect the cycling of carbon through Earth systems.
  • Identify the primary causes of the annual fluctuations in the Keeling CO2 curve.
  • Provide examples of how CO2 concentrations in Earth's atmosphere are linked to annual cycles of plant life.
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Teacher Notes

The resources in this Earth Science Investigation are linked together to form a coherent learning sequence using a four-step process.

Investigation Steps and Overview

Step 1. Ask Questions

In this phase of the investigation students identify and discuss the issue or problem and begin to gather background information.

Time required: 80 minutes


In this step, students use a static visualization to explore how CO2 concentration is related to global temperature change. They then use a short reading to review the nature of greenhouse gases, carbon sinks and sources, and elements of the carbon cycle.

  • 1.1 - CLEAN resource: Atmospheric Carbon Dioxide from Mauna Loa
  • 1.2 - NOAA resource: Basics of the Carbon Cycle and the Greenhouse Effect
  • 1.3 - CLEAN resource: Interactive Carbon Cycle
  • Step 2. Plan Approach to Inquiry

    In this step of the unit students develop their approach to answering the question developed in the first step of the investigation.

    Time required: 120 minutes


    In this step, students do an initial exploration and model the relationship between CO2 concentration and plant growth using an online interactive resource and investigate regional differences in CO2 fluctuations using a climate model simulation.

  • 2.1 - CLEAN resource: Mauna Loa in the Classroom
  • 2.2 - NASA and University Wisconsin resources:
  • 2.3 - CLEAN resource: Global Carbon Budget 1960-2100
  • Step 3. Conduct Investigation

    In this step, students conduct their own investigation and prepare to communicate ideas.

    Time required: 120 minutes


    In this step, students use an interactive graphing tool and NASA's Near Earth Observatory to carry out an investigation of their own design and focus on seasonal patterns of CO2 concentrations at various locations around the globe.

  • 3.1 - NOAA resource: GHG graphing tool
  • 3.2 - NOAA and CLEAN resources:
  • 3.3 - CLEAN resource: Part 6 of Carbon Pathways EET chapter
  • Step 4. Communicate Outcomes

    In the final step of the investigation, students do a final project and communicate their results using an interactive model to construct experiments and generate data.

    Time required: 90 minutes


    In this step, students do a final project and communicate their results using an interactive model to construct experiments and generate data. They then describe how concentrations of CO2 are impacted by both seasonal and long-term changes in land and ocean uptake

  • 4.1 - NOAA resource: Carbon Dioxide: Earth's Hottest Topic is Just Warming Up
  • 4.2 - CLEAN resource: Global Carbon Budget 1960-2100
  • Time Required to Complete the Investigation

    3 - 5 hours (or four to seven 45-minute periods) of class time to complete all the activities listed in this investigation. Teachers may want to choose a subset of the activities listed here, or substitute one they deem more appropriate at any point. The sequence can be done in 3 hours or less if a proportion of the activities, particularly readings and short videos, are assigned as homework instead of done in class.

    Three Dimensional Learning

    The standards listed below are composed of three distinct and equally important dimensions of science learning. These dimensions combine to form each standard, and each dimension works with the other two to help students build a cohesive understanding of science over time. This three-dimensional learning system provides a research-based, up to date set of science standards that give educators the flexibility to design classroom learning experiences which stimulate students' interest in science and help them become science literate and informed citizens. By engaging with multiple learning experiences that use all three dimensions over time, students move toward mastery of the target performance expectations listed below.

    Elements of 3-Dimensional Learning

    Disciplinary Core Ideas
    • HS LS2.B: Cycles of Matter and Energy Transfer in Ecosystems: Photosynthesis and cellular respiration are important components of the carbon cycle, in which carbon is exchanged among the biosphere, atmosphere, oceans, and geosphere through chemical, physical, geological, and biological processes. (HS-LS2-5)
    • HS.ESS2.D1 Weather and Climate: Changes in the atmosphere due to human activity have increased carbon dioxide concentrations and thus affect climate.(HS-ESS2- 6),(HS-ESS2-4)
    • HS.ESS3.D3 Global Climate Change: Through computer simulations and other studies, important discoveries are still being made about how the ocean, the atmosphere, and the biosphere interact and are modified in response to human activities. (HS-ESS3-6)
    Science and Engineering Practices
    • #1 Asking questions
    • #2 Developing and using models
    • #3 Planning and carrying out investigations
    • #4 Analyzing and interpreting data
    • #6 Constructing explanations
    • #8 Obtaining, evaluating, and communicating information
    Cross Cutting Concepts
    • #1 Patterns
    • #2 Cause and effect
    • #4 Systems and system models
    • #5 Energy and matter: Flows, cycles, and conservation
    • #7 Stability and Change
    Target Performance Expectations

    NOTE: The lessons and activities in this Earth Science Investigation are just one step in reaching the performance expectations listed below.

    HS-ESS2-2 Analyze geoscience data to make the claim that one change to Earth's surface can create feedbacks that cause changes to other Earth systems.
    HS-LS2-5 Develop a model to illustrate the role of photosynthesis and cellular respiration in the cycling of carbon among the biosphere, atmosphere, hydrosphere, and geosphere.

    Additional Resources