Notes from our reviewers

The CLEAN collection is hand-picked and rigorously reviewed for scientific accuracy and classroom effectiveness. Read what our review team had to say about this resource below or learn more about how CLEAN reviews teaching materials.

• Teaching Tips
  The first lesson may be too difficult for some high school students and is likely too abstract for many ELL students without additional support. Educators may wish to pre-teach important vocabulary (reactants, products, reservoirs, etc.). The first lesson is the most complicated logistically and conceptually, whereas the two subsequent lessons are simpler. Review the answer key and instructions thoroughly before each activity. It may take some time to orient themselves with the activity. This activity would work well for use in the middle or toward the end of a unit about carbon cycles and their relation to climate change because it requires too much background knowledge for the introduction to the unit. For the third lesson (pros/cons of different mitigation strategies), teachers could have more advanced students conduct their own research and come up with their own ideas rather than using the prepared handouts. The list of challenges associated with the "One Fewer Child" mitigation strategy is very thorough, however, educators may still need to proceed with caution when discussing this controversial subject.
• About the Science
  The science in this activity covers the carbon cycle, reservoirs, climate change, climate feedback loops, and human impacts/mitigation. Students use the following datasets in this activity: Lesson 1 uses the amounts of (flux and non-flux) carbon from climate.gov and energy.gov; Lesson 2 uses NOAA atmospheric carbon concentrations from sites across the US, as well as sea-level rise projected impacts on Hawaii; Lesson 3 uses amounts of carbon emissions from daily life. All data is from 2000 or more recent, with the majority of it from 2010 or newer. This resource has high scientific accuracy and addresses potential misconceptions and confusion. It addresses that carbon cannot be created/destroyed, the "how" of a warming planet through data and experiential learning, and the complexity inherent in solutions to carbon emissions. It is affiliated with the United States Department of Agriculture and other reputable sources and has embedded links to many high-quality (primarily US government) resources. Comments from expert scientist: The resource does a good job providing citations and reputable activities (i.e., they include a NOAA interactive game). The content seems scaled to the audience (9-12th graders) and provides general and specific scientific content. Overall, this resource provides currently up to date, and well-thought-out information. The only scientific concern is the oversimplification of content. An example of this would be that "organic carbon in soil is released to CO2 through microbial respiration", while sunlight can contribute ~30% of CO2 release. Another example is stating that "CO2 is the only carbon in the atmosphere", while CH4 (methane) also substantially contributes. Perhaps simplifications are intentional for the audience. I will note that many of the figures and metrics provided will become out of date when additional climate reports become available. (e.g., activity 1 is based on carbon reservoirs which will shift with time).
• About the Pedagogy
  This activity includes 3 lessons which can be done together or as stand-alone (the first lesson spans two class periods). The activities build on one another, but can also be done independently if another activity is used to cover similar material. In lesson 1, students model the carbon cycle/flux (both natural and human-made). In lesson 2, students learn about the greenhouse effect and how it's amplified by the warming planet's destruction of habitats that perform natural carbon sequestration (feedback loops). In lesson 3, students explore the pros and cons of different mitigation strategies to reduce human carbon emissions. These activities include working with models and worksheets, hands-on experiments and data analysis, and a poster. The learning objectives of each of the lessons are as follows: students will understand how carbon moves between the Earth's spheres and how humans affect that movement; students will model the greenhouse effect, analyze data, and examine a positive feedback loop that is being destabilized; students will analyze the pros/cons of different carbon emission mitigation strategies. Lesson 1 requires a solid understanding of respiration, photosynthesis, combustion (and terms like reactants and products). Students would also benefit from an existing base knowledge of the carbon cycle/reservoirs. Lesson 3 requires a basic understanding of the carbon cycle/emissions but contains quick links to provide that background knowledge if needed. The resource includes a teacher's guide for each activity. The teacher's guide is extremely thorough (slide-by-slide annotations), but very long. The 95-page educator guide includes a script for the Powerpoints and printouts of all of the game pieces associated with the activities. Instructions for games, prep, set-up, and potential answers/answer key are provided. Activities are clearly organized and learning outcomes are clearly stated for each activity. The activities are very hands-on with different options for student roles/levels of involvement. High engagement level, even the introductory slide material has interactive components.
• Technical Details/Ease of Use
  Some materials such as the Mylar space/emergency blanket are not found in most classrooms and may need to be purchased each time the activity is used. The most expensive element is a space blanket (available on Amazon - 10 for $20). Other materials include stopwatches, meter sticks, yarn, beanbags/balls, ziplock bags, plastic cups, and thermometers, and can likely be bought for under $20 total. Clear instructions are provided for all technological components. The activity works best if students can use computers in groups, but has adaptations included for students without technology. Overall, this is a long resource that requires a substantial amount of teacher prep work for the first two lessons. Educators may want to allow 1-2 hours of prep time for all three lessons. The educator may wish to make copies of the many components well ahead of time. To save time, students may cut their own cards or make one class set and laminate them.