Carbon TIME: Human Energy Systems Unit

Human Energy Systems is one of the six Carbon TIME units. If you are new to teaching Carbon TIME, read the Carbon TIME FAQ: Which Units Should I Teach.

The Human Energy Systems Unit supports students in using core disciplinary ideas, science practices, and cross-cutting concepts to develop scientific explanations of how different energy systems transform matter and energy as they grow, move, and function.

Follow these steps to get ready to teach the Human Energy Systems Unit

Lead Editor for 2019 Version

Kirsten D. Edwards, Department of Teacher Education, Michigan State University

Principal Authors

Hannah K. Miller, Department of Teacher Education, Northern Vermont University

Wendy Johnson, Department of Teacher Education, Michigan State University

Jenny Dauer, School of Natural Resources, University of Nebraska-Lincoln

Beth Covitt, College of Arts and Sciences, University of Montana

Craig Kohn, Department of Teacher Education, Michigan State University

Bonnie McGill, Kansas Biological Survey, University of Kansas

Charles W. (Andy) Anderson, Department of Teacher Education, Michigan State University

Contributing Authors

Sarah Bodbyl Roels, Elizabeth Xeng de los Santos, Jennifer Doherty, Allison Freed, Bonnie McGill, Lindsey Mohan, Emily Scott, Alex Walus Beth Covitt, Jennifer Doherty, Emily Scott, Nick Verbanic

Illustrations

Craig Douglas

This research is supported in part by grants from the National Science Foundation: A Learning Progression-based System for Promoting Understanding of Carbon-transforming Processes (DRL 1020187) and Sustaining Responsive and Rigorous Teaching Based on Carbon TIME (NSF 1440988). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation or the United States Department of Energy.

Contact the MSU Environmental Literacy Program for more information: EnvLit@msu.edu.

The goal of the Human Energy Systems unit is to introduce students to carbon cycling at a global scale and the implications of human fossil fuel use for climate change. Students:

Investigate patterns of change in Earth systems (global temperatures, global sea levels, Arctic sea ice, atmospheric CO₂) and use the Greenhouse Effect to explain how increases in greenhouse gas concentrations drive changes in other systems;
Explain how three key fluxes (photosynthesis, cellular respiration, combustion of fossil fuels) affect the atmospheric CO₂ pool;
Explain how human actions affect CO₂ fluxes; and
Predict effects of changes in human actions on the atmospheric CO₂

The Research Base

Carbon is the key! In the unit, students learn to tell the story of how matter and energy are transformed as they move through human energy systems. A particularly powerful strategy for explaining how Earth systems transform matter and energy involves tracing carbon atoms. For more information about the Next Generation Science Standards disciplinary core ideas included in this unit see the sections on the Large Scale Four Questions below and the Unit Goals

Research base. This unit is based on learning progression research that describes the resources that students bring to learning about human energy systems and the barriers to understanding that they must overcome. It is organized around an instructional model that engages students in three-dimensional practices.

Students’ Roles and Science Practices

Human Energy Systems is the culminating unit in the Carbon TIME sequence, focusing on global-scale phenomena: climate change and global carbon cycling. We recommend that teachers complete the Systems & Scale, Plants, and Ecosystems units before the Human Energy Systems unit if possible. The foundational knowledge introduced in these units helps prepare students to engage in conversations and activities that require a basic understanding of photosynthesis, cellular respiration, and combustion of fossil fuels (on a cellular or atomic-molecular scale) and apply these concepts to carbon cycling and energy flow (on a global scale). It is through examining the pools and fluxes of carbon at a global scale that students will be able to make connections between energy use, combustion of fossil fuels, carbon emissions, and climate change.

The Carbon TIME instructional model reflects the two phases of the unit. The first phase focuses on helping students to understand, analyze, and explain multiple phenomena associated with climate change (What is happening to the planet?). The second phase focuses on global carbon cycling (What causes changes in CO₂?). In each phase students practice the roles of questioner, investigator, and explainer.

Phase 1: What is happening to the planet? (climate change)

In Lessons 1-3 students question, investigate, and explain four phenomena associated with climate change: Arctic sea ice, global sea levels, global average temperatures, and atmospheric CO₂ concentrations.

Lesson 1: After taking the unit pretest, students begin by expressing their ideas and questions around a single phenomenon: Arctic sea ice. They begin with ideas and questions about a single pair of images, comparing the extent of Arctic sea ice in 1979 and 2016. They then investigate data on Arctic sea ice over multiple years, learning to make graphs that show two patterns: (a) the extent of ice varies unpredictably from one year to the next, and (b) there is a long-term trend toward reduced ice cover.

Lesson 2: Students investigate multiple representations of data about three other phenomena, comparing the representations to look for patterns in the data. They end the lesson with four clear long-term trends:

The extent of Arctic sea ice is decreasing
Sea levels are rising
Global average temperatures are rising
Global concentrations of CO₂ are rising

Lesson 3:

Students learn about the Greenhouse effect and use it to explain the connections among the long-term trends: Increasing CO₂ levels are causing increases in global temperatures; the increasing temperatures are causing sea level to rise and ice to melt. Thus, atmospheric CO₂ is the driver—the factor that causes change in the other variables.

Phase 2: What causes changes in CO2? (global carbon cycling)

In the second half of the unit students investigate and explain “what drives the driver”—what is causing changes in atmospheric CO₂ levels.

Lesson 4: Students begin by sharing questions and hypotheses and make predictions about how reducing fossil fuel use will affect atmospheric CO₂ using the Big Ideas Probe. Students figure out how to answer the driving question by tracing carbon-containing molecules through a series of movements and chemical changes as they travel through different matter pools in Earth systems. At each stage in these processes they answer Four Questions about what is happening: The Carbon Pools Question, the Carbon Cycling Question, the Energy Flow Question, and the Stability and Change Question.

Note that, in Carbon TIME, NGSS
crosscutting concepts serve as the “rules of grammar” for producing a scientific performance. With respect to bread molding, high quality explanations should attend to the following rules that are implied by crosscutting concepts. Explanations should attend to:

Scale by explaining events and phenomena at the appropriate scale (see more in the structure and function bullets below).
Systems and system models and energy and matter by following rules for tracing matter and energy through systems and system models. For example, neither energy nor matter should be created or destroyed as it moves into, through, or out of a system.
Structure and function by linking structures and functions in explanations at each scale.
- Global scale (tracing fluxes of carbon and energy through different global carbon pools)
- Macroscopic scale (tracing matter and energy through processes occurring inside plants, animals, and decomposers)
- Atomic-molecular scale (tracing matter and energy through chemical processes—digestion, cellular respiration, and biosynthesis—involving molecules with different structures and properties)

In particular, students should learn to answer the Four Questions in three important contexts:

At the macroscopic scale, they relate our economic activities and lifestyle choices to carbon-transforming processes, especially combustion of fossil fuels. Students should understand both activities that directly use fossil fuels (such as driving a car) and activities that indirectly use fossil fuels (such as using electrical appliances or buying products that require fossil fuels for manufacture and transportation).
Relating local systems, actions, and choices to global effects and outcomes, particularly increasing concentrations of carbon dioxide in the atmosphere.
Relating changes in global carbon pools (the atmosphere, biomass, soil organic carbon, and organic carbon in fossil fuels) to the balance of fluxes of carbon between these pools.

Students use three different kinds of pool-and-flux models to explain both the annual cycle and the long-term trend in CO2 concentrations:

The Tiny World Game (Activity 4.3) is a hands-on activity in which students move counters to investigate the effect of different balances among photosynthesis, cellular respiration, and combustion fluxes on atmospheric, environmental organic carbon, and fossil fuel pools.
The Global Carbon Model (Activity 4.4) is an online model that students can manipulate to predict how different changes in carbon fluxes will affect carbon pools.

The Global Carbon Cycling Diagram (Optional Activity 4.5) adds the oceans as another carbon pool. Students make predictions that include carbon fluxes into and out of the oceans using the diagram.

Lesson 5: Students learn from Lesson 4 that combustion of fossil fuels is the unbalanced flux that drives the continuing increase in atmospheric CO₂ concentrations (and therefore climate change). In Lesson 5 they explore how human activities, including their own lifestyles, depend on combustion of fossil fuels—often in hidden ways. Students investigate how lifestyles associated with different countries (United States, France, China, and Ethiopia) lead to vastly different rates of fossil fuel combustion. They also examine how their own everyday activities (e.g., buying a pizza, washing dishes) use energy from fossil fuels and changes that could reduce carbon emissions.

Lesson 6: The unit concludes with a series of activities in which students make projections of how different scenarios will affect global temperatures as atmospheric CO₂ concentrations. They use a computer to make projections, then discuss different scenarios for Earth’s future, and how those scenarios will affect their lives.

Science Literacy

A note on media literacy. This unit makes extensive use of data and models from authoritative sources. Its contents are not scientifically controversial and are consistent with the Next Generation Science Standards. The data and models in this unit are complex, but critically important. The unit has many scaffolds, including the Questions, Connections, Questions Student Reading Strategy, to scaffold students’ understanding.

Some students might respond to the material presented in this unit by offering conflicting claims they have heard about climate change from their families, friends, or the media. Footnotes are included throughout the Teacher’s Guide to help you respond to these claims using with the evidence the scientific community looks to interpret these conflicting claims. Although scientists view climate change as a matter of scientific evidence and not one of morals and values, the students may feel that their core values and viewpoints are being threatened, which could in turn cause them to disengage. The footnotes included in this unit are intended to provide additional perspectives you might use to help your students interpret the claims they are making in light of the available evidence for anthropogenic climate change.

While we want to encourage students to ask questions and engage in dialogue about the conflicting claims about climate change, we also want to encourage these conversations to be constrained by accurate scientific evidence. Look for footnotes throughout the Teacher’s Guide-- these are designed to help you navigate these conversations if they arise.

How much detail? There are more complicated and more scientifically accurate ways of talking about chemical bonds and about changes in energy; we discuss some of those in detail in our educator resource: Carbon TIME Content Simplifications. But our learning progression research has shown that there is an important tradeoff here—many students get lost in the details and never learn a basic coherent story that answers the driving question. The Next Generation Science Standards take a clear position on this tradeoff; a coherent story based on principles such as matter and energy conservation are more important than the details. Consult the Unit Sequence tab and the sections on Extending the Learning at the end of each Activity page to decide how much detail is appropriate for your students.

Before beginning the Human Energy Systems Unit, you need to decide what to teach and importantly, what not to teach! Use this page to choose the unit sequence that’s most appropriate for your students.

Some activities are TWO-TURTLE ACTIVITIES (), which place a higher demand on students. Decide whether the higher demand required by these activities will be useful or distracting for your students. The Carbon TIME Turtle Trails Document document provides further info about choices for making units more or less demanding, depending on your students’ needs.

Unless otherwise noted in the table below, all activities in the unit should be taught.

Human Energy Systems Unit Sequence and Decisions Table

Here, we present two ways to think about how lessons are sequenced in the Human Energy Systems Unit. The Instructional Model, immediately below, emphasizes how students take on roles of questioner, investigator, and explainer to learn and apply scientific models in each section of the unit. Further below, the Unit Storyline Chart highlights the central question, activity, and answer that students engage with in each lesson of the Human Energy Systems Unit.

Instructional Model

Like all Carbon TIME units, this unit follows an Instructional Model (IM) designed to support teaching that helps students achieve mastery at answering the driving question through use of disciplinary content, science practices, and crosscutting concepts. To learn more about this design, see the Carbon TIME Instructional Model.

The instructional model for the Human Energy Systems Unit includes two phases, described in the Unit Overview, in which students play the role of questioners, investigators, and explainers. The first phase focuses on helping students to understand, analyze, and explain multiple phenomena associated with climate change (What is happening to the planet?). The second phase focuses on global carbon cycling (What causes changes in CO₂?). Across the unit, classroom discourse is a necessary part of three-dimensional Carbon TIME learning. The Carbon TIME Discourse Routine document provides guidance for scaffolding this discourse in lessons.

The core of the Carbon TIME Instructional Model is the Observation, Patterns, Models (OPM) triangle, which summarizes key aspects to be attended to as the class engages in unit inquiry and explanation. The OPM triangle for the Human Energy Systems Unit, shown below, articulates the key observations students make during the unit investigation, the key patterns they identify through analyzing their investigation data, and the central scientific model that can be used to answer the unit’s driving question.

Observations, Patterns, and Models for Phase 1: Climate Change

Observations and patterns: trends in global climate data.

Students investigate multiple representations of data about four global phenomena, comparing the representations to look for patterns in the data. They end the Lesson 2 with four clear long-term trends:

The extent of Arctic sea ice is decreasing
Sea levels are rising
Global average temperatures are rising
Global concentrations of CO₂ are rising

Models: The Greenhouse Effect and CO₂ as the driver. Students learn to use the Greenhouse effect to explain the connections among the long-term trends: Increasing CO₂ levels are causing increases in global temperatures; the increasing temperatures are causing sea level to rise and ice to melt. Thus, atmospheric CO₂ is the driver—the factor that causes change in the other variables.

Observations, Patterns, and Models for Phase 2: Global Carbon Cycling

Observations and patterns: Students use visualizations and graphs to investigate changes in atmospheric CO₂ concentrations. Key patterns include:

The annual cycle: CO₂ concentrations in the northern hemisphere decline every summer and rise every winter.
The long-term trend: Global CO₂ concentrations have increased from about 310 to 400 ppm since the late 1950s.

Models (and Explanations): Students explain carbon cycling and energy flow between carbon pools by connecting global, macroscopic, and atomic-molecular scales, and answering the Four Questions:

Carbon Pools: carbon atoms are found in CO₂, living organisms, soil organic carbon, oceans, and fossil fuels
Carbon Fluxes: Changes in photosynthesis drive the annual cycle; combustion of fossil fuels drives the long-term trend.
Energy Flow: CO₂ and other greenhouse gases cause climate change.
Stability and Change: The photosynthesis and cellular respiration fluxes are large, but balanced. So, the smaller but unbalanced flux from combustion of fossil fuels is steadily increasing the size of the atmospheric CO₂

Unit Storyline Chart

Another way to familiarize yourself with the sequence of lessons in the Human Energy Systems Unit is with the Unit Storyline Chart depicted below. The Unit Storyline Chart summarizes a unit phenomenon-based driving question associated with each lesson, what classes will do in each lesson to address the question, what conclusions they will come to, and how they will transition to a subsequent lesson.

Download Unit IM and Storyline Chart

The tables below show goals for this unit in two forms. A list of Next Generation Science Standards (NGSS) addressed by this unit is followed by a table showing specific target performances for each activity.

Next Generation Science Standards

The Next Generation Science Standards (NGSS) Performance Expectations that middle and high school students can achieve through completing the Ecosystems Unit are listed below. To read a discussion of how the Carbon TIME project is designed to help students achieve the performances represented in the NGSS, please see Three-dimensional Learning in Carbon TIME.

High School

Matter and Its Interactions. HS-PS1-7. Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.

http://www.nextgenscience.org/hsps1-matter-interactions

Ecosystems: Interactions, Energy, and Dynamics. 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.

http://www.nextgenscience.org/hsls2-ecosystems-interactions-energy-dynamics

Ecosystems: Interactions, Energy, and Dynamics. HS-LS2-7. Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.
Earth’s Systems. 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.
Weather and Climate. 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.

http://www.nextgenscience.org/hsls2-ecosystems-interactions-energy-dynamics

Earth’s Systems. HS-ESS2-6. Develop a quantitative model to describe the cycling of carbon among the hydrosphere, atmosphere, geosphere, and biosphere.

http://www.nextgenscience.org/hsess-es-earth-systems

Earth and Human Activity. HS-ESS3-4. Evaluate or refine a technological solution that reduces impacts of human activities on natural systems.

http://www.nextgenscience.org/hsess3-earth-human-activity

Earth and 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.

http://www.nextgenscience.org/hsess3-earth-human-activity

Earth and Human Activity. HS-ESS3-6. Use a computational representation to illustrate the relationships among Earth systems and how those relationships are being modified due to human activity.

http://www.nextgenscience.org/hsess3-earth-human-activity

Middle School

MS-ESS2-1. Develop a model to describe the cycling of the Earth’s materials and the flow of energy that drives this process.
Earth and Human Activity. MS-ESS3-3. Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment.

http://www.nextgenscience.org/msess3-earth-human-activity

Human Impacts. MS-ESS3-4. Construct an argument supported by evidence for how increases in human population and per-capital consumption of natural resources impact Earth's systems.

http://www.nextgenscience.org/msess-hi-human-impacts

Earth and Human Activity. MS-ESS3-5. Ask questions to clarify evidence of the factors that have caused the rise in global temperatures over the past century.

http://www.nextgenscience.org/msess3-earth-human-activity

Target Performances for Each Activity

All Carbon TIME units are organized around a common purpose: assessing and scaffolding students’ three-dimensional engagement with phenomena. Every Carbon TIME activity has its specific expectation for students’ three-dimensional engagement with phenomena, what we call its target performance. Each activity also includes tools and strategies that teachers can use to asses and scaffold the target performance in rigorous and responsive ways.

The target performances for each activity in the Ecosystems unit are listed in the table below.

Materials List

Download Zip File of All Unit Materials

Materials to Purchase PDF

Resources You Provide

Activity 1.1

pencils (1 per student, for paper version)

Activity 1.2

sticky notes (1 per student)
(Optional) Powers of Ten video

Activity 1.3

pencil (1 per student)

Activity 1.4

1.3 Graphing Arctic Sea Ice Worksheet (completed worksheets from previous activity)

Activity 1.5

1.3 Graphing Arctic Sea Ice Worksheet (completed worksheets from previous activity)

Activity 2.1

Activity 2.2

Jigsaw Cards (already distributed during previous activity)

Activity 2.3

2.1 Finding Patterns Tool for Earth Systems (from previous activity)
2.1 Assessing the Finding Patterns Tool for Earth Systems

Activity 2.4

2.1 Finding Patterns Tool for Earth Systems (completed from previous activity)
2.1 Assessing the Finding Patterns Tool for Earth Systems

Activity 3.1

Activity 3.2

Activity 3.3

Activity 4.1

3.3 Explaining Relationships Between Earth Systems Worksheet (completed from Lesson 3)

Activity 4.2

Activity 4.3

Markers for Tiny World Pool and Flux Activity to be used on the placement (30 per pair of students)

Activity 4.4

Activity 4.5

Pump handle video (https://www.esrl.noaa.gov/gmd/ccgg/trends/history.html ) See the Lesson 4 Background information for more information about this video.
Keeling & South Pole PPT slides & video: https://youtu.be/UatUDnFmNTY
Primary productivity PPT slides & video: http://eoimages.gsfc.nasa.gov/images/globalmaps/data/mov/MOD17A2_M_PSN.mov
Explanation of how changes in sunlight drive changes in photosynthesis, see https://www.youtube.com/watch?v=WgHmqv_-UbQ
Website on ocean acidification: https://ocean.si.edu/ocean-life/invertebrates/ocean-acidification
Media representations of carbon cycle:
- ESRL
- WGBH

Activity 5.1

(optional) Calculator (1 per group of four students)

Activity 5.2

(From previous lesson) 5.1 Lifestyle Cards (1-2 sets per class)
(From previous lesson) 5.1 Extreme Makeover: Lifestyle Edition Worksheet (1 per student)
(From previous lesson) 5.1 Secrets Revealed! Worksheet (1 per student)

Activity 5.3

Activity 5.4

Chart paper (1 per group of four students)

Activity 6.1

Activity 6.2

Activity 6.3

Pencils (1 per student)

Resources Provided

Activity 1.1

1.1 Human Energy Systems Unit Pretest (1 per student or online)
1.1 Assessing the Human Energy Systems Unit Pretest

Activity 1.2

Activity 1.3

1.3 Graphing Arctic Sea Ice PPT
1.3 Graphing Arctic Sea Ice Worksheet
1.3 Grading the Graphing Arctic Sea Ice Worksheet
Website to retrieve data: http://nsidc.org/data/seaice_index/archives/image_select

Activity 1.4

Activity 1.5

Activity 2.1

Activity 2.2

2.2 Expert Group A Worksheet (1 per student in Group A)
2.2 Expert Group B Worksheet (1 per student in Group B)
2.2 Expert Group C Worksheet (1 per student in Group C)
2.2 Expert Group D Worksheet (1 per student in Group D)
2.2 Assessing Expert Group A Worksheet (1 per class)
2.2 Assessing Expert Group B Worksheet (1 per class)
2.2 Assessing Expert Group C Worksheet (1 per class)
2.2 Assessing Expert Group D Worksheet (1 per class)

Activity 2.3

2.3 Home Groups: Share Expertise PPT

Activity 2.4

2.4 Evidence-Based Arguments for Patterns in Earth Systems PPT

Activity 3.1

3.1 Millions of Flasks of Air Reading (1 per student)
(Optional) “Climate Change is Clear Atop Mauna Loa” a 12-minute radio story about climate change: http://www.npr.org/templates/story/story.php?storyId=9885767

Activity 3.2

3.2 The Greenhouse Effect Reading
3.2 The Greenhouse Effect Simulation Worksheet
3.2 Grading The Greenhouse Effect Simulation Worksheet
Greenhouse Effect PhET simulation: https://phet.colorado.edu/en/simulation/greenhouse
Optional data (“Global Warming's Six Americas”) of attitudes toward climate change: https://www.americanprogress.org/issues/green/reports/2009/05/19/6042/global-warmings-six-americas/

Activity 3.3

Activity 4.1

4.1 Questions for this Lesson PPT
(Extending the learning) New York Times Keeling article: https://nyti.ms/2jCmhVE
(Optional) Pumphandle Video (discussed in Background Information for this lesson)

Activity 4.2