Stabilization Wedges

Carbon Mitigation Initiative (CMI), Princeton University
Type Category
Instructional Materials
Game , Informative Text
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be “fully aligned,” the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.


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5 Project Drawdown

I highly recommend checking out the book "Drawdown: The Most Comprehensive Guide to Reversing Global Warming" edited by Paul Hawken, There may be some great texts that could supplement this material.


The Stabilization Wedges Game is a team-based exercise that teaches players about the scale of the greenhouse gas problem, plus technologies that already exist to dramatically reduce our carbon emissions and get us off the path toward dramatic and damaging climate change. In this game, students are introduced to the concept of stabilization wedges as a way to help reduce carbon emissions. Each stabilization wedge strategy is equal to a reduction of 1 billion tons of emissions per year. Students are put into teams of 3-6 and create a strategy using eight stabilization wedges to reduce carbon emissions. After determining which of four different sectors (electricity production, heating and direct fuel use, transportation, and biostorage) strategies they will choose, students develop a wedge triangle and corresponding 5 minute oral report justifying their choices. The team with the overall best justification, not necessarily best choices, will win.


The recommended time for this activity is 2-3, 40-50 minute class periods depending on the number of teams. Classes with a large number of teams may take three class periods. The first class period should be spent on climate change, introduction to wedges, team determination, and expert determination. The second, and possibly third, class period(s) should be spent on playing the game, development of the wedge triangle, oral report presentations, and judging. Closure/ assessment of student learning questions are provided.

Teachers should be aware that one of the contributors to this activity was BP.

Intended Audience

Educator and learner
Educational Level
  • Grade 12
  • Grade 11
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

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

Clarification Statement: Examples of data on the impacts of human activities could include the quantities and types of pollutants released, changes to biomass and species diversity, or areal changes in land surface use (such as for urban development, agriculture and livestock, or surface mining). Examples for limiting future impacts could range from local efforts (such as reducing, reusing, and recycling resources) to large-scale geoengineering design solutions (such as altering global temperatures by making large changes to the atmosphere or ocean).

Assessment Boundary: none

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
Students are tasked with analyzing several different strategies to determine which eight would help reduce the amount of carbon emissions while being constrained to how many from each sector they can use to develop their plan. Throughout the game, students are focused on reducing carbon emissions which affect natural systems on Earth. There is little focus on the impacts of carbon emissions other than the beginning activity talking about climate change. To put more focus on the impact of human activities (carbon emitting activities), more discussion into the effects of climate change on natural systems would need to be incorporated. NASA Earth’s Dynamically Changing Climate ( lesson would solidify the effects of climate change and could be used to prior to the stabilzation wedges game.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
Students create a wedge triangle with eight different strategies they choose, based on scientific knowledge, criteria, and tradeoff considerations to reduce carbon emissions by 8 billion tons per year. Students are tasked with evaluating their design by judging it on a scale of 1-5 (5 being best) in terms of stakeholder groups such as: taxpayer/ consumers, energy companies, environmental groups, manufacturers, industrialized country governments, and developing country governments. This evaluation will help student teams justify their reasoning behind their choices when developing their oral reports. The student teams and teacher will determine which group has the best case for their designed reduction plan based on their justifications. To include the entire practice, student teams could be given a chance to refine their wedge triangles based on feedback after presenting their oral reports. The class could also come up with a consensus wedge triangle that would have the fewest costs associated with it.

Disciplinary Core Ideas

This resource appears to be designed to build towards this disciplinary core idea, though the resource developer has not explicitly stated so.

Comments about Including the Disciplinary Core Idea
Students are instructed to take into consideration constraints such as cost and technology when considering what strategies to incorporate into their wedge triangle. When they evaluate their choices based on what they think stakeholders may think, students then should take into consideration cost, safety, reliability, and aesthetics. Students may need clarification on some of the challenges as well as abbreviations. The teacher guide provides more detailed information for the 15 strategies presented to students. To make this more explicit, the small table where students rank how each strategy would be scored by a stakeholder should be expanded. An expanded ranking rubric that looks at each stakeholder’s take on cost, safety, reliability, and aesthetics would help make this more explicit. Students could also discuss what it would take to achieve both a low (1) and high (5) ranking.

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
Students are directed to consider technological viability of their strategies as they choose which strategies to include in their wedge triangle. While students are presented with different technological strategies, they must consider how viable they would be to scale up to create an entire wedge. In some cases, the strategy may appear good to use, but on the large scale, would not be viable (solar electricity). Students may require additional information (which is provided in the teacher guide) to make more informed decisions due to very little information and explanation of some concepts on the Stabilization Wedge Table they are instructed to use to design their wedge triangle. In order to address the full Disciplinary Core Idea, teachers could have students explore waste with the, “ 5E Resource Conservation: E-Waste,” ( activity and to address ecosystem degradation with the, “Will there be enough freshwater?” ( activity.

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
One of the criteria students will need to use to determine viability of their chosen strategy is how well it can be scaled up. Students may struggle with this because of the lack of information presented to them in the Wedge Table. If questions do arise, teachers could present students with the information pages in the teacher’s guide. Teachers could make this stronger by having students investigate why some things could work on a small scale, but are not viable on the large scale due to land requirements or cost. Some information is included on this in the teacher’s guide. Teachers may encourage students to research this, as needed using the EPA website or another accurate, unbiased source.

Resource Quality

  • Alignment to the Dimensions of the NGSS: Students are actively using Science and Engineering Practices to design a solution (decreasing carbon emissions) to a problem (we are emitting too much carbon into the atmosphere). Students do develop ideas about the Disciplinary Core Ideas, but would require additional activities or information to fully understand both. Teachers could provide students with more information by giving them the in depth strategies pages provided in the teacher’s guide. Both targeted Crosscutting Concepts also require additional activities to strengthen students use of them in this activity. Teachers could begin with an introductory activity to build in more understanding of feedback systems (Stability and Change) and be more explicit with scaling up some of the strategies (Scale, Proportion, and Quantity) to make the Crosscutting Concepts have more focus. Teachers could also strengthen the activity by encouraging students to generate and answer their own questions which would help students make connections to their prior experiences. Students will need to use all three dimensions in order to create a well thought out oral argument for their wedge triangle.

  • Instructional Supports: The lesson is an authentic task and the scenario reflects how science and engineering are experienced in the real world. It supports 3 dimensional learning and students express, justify and represent their ideas.The presented scenario is very relatable to students everywhere. Global climate change and reducing carbon emissions are both topics they are exposed to on a regular basis in the media. Students incorporate all three dimensions of the Next Generation Science Standards in the development of their solution, wedge triangle, to reduce carbon emissions. Within the teams, students should question each other to clarify questions and present ideas for the choices of strategies to use. The teacher should question the teams as they go through the process of developing their wedge triangle. The teacher’s guide does not provide any guidance or support for differentiated instruction. For struggling students or teams, the teacher could provide the in depth strategies pages to increase their knowledge about the 15 pre-selected strategies. Students with high interest could do more research into other alternative stability wedge strategies that are not presented as part of the selected ones for the game.

  • Monitoring Student Progress: Teachers would be able to observe student’s three dimensional learning while visiting each team as they are playing the game in the development of their wedge triangle. There is no embedded formative assessment while students are in the game phase of the activity. The teacher would have to develop a checklist to use in order to assess student understanding while they are developing their wedge triangles and oral presentations. The teacher’s guide does give teachers a few questions to use to check for student’s understanding of the wedges concept and its application. Teachers are given some examples, but not in any great detail, of some student responses to the questions. Teachers would need to develop exemplar answers to those questions. The Wedge Workshop includes a question about scores from each stakeholder group and the corresponding chart students fill out which could be used as formative assessment. There are no provided examples of either a strong or weak triangle, but the focus of the activity is on the argument students make for the validity of their triangle. It would be up to the teacher to develop a judging rubric for various stakeholders to use while teams are presenting their oral arguments for their wedge triangles. Teachers would need to either recruit stakeholders from outside the school or “train” students in the teams to act as stakeholders in order to judge the presentations.

  • Quality of Technological Interactivity: Teachers will need computer access to download the PDF for the game rules, game pieces, and teacher’s guide.