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Climate Feedback Loops

Run the Climate Feedback Loops MicroSim Fullscreen

About This MicroSim

This MicroSim uses an interactive causal loop diagram to show how positive feedback loops in the climate system amplify initial warming. The network graph displays key climate variables as nodes -- including global temperature, Arctic ice cover, albedo, permafrost extent, methane release, water vapor, and ocean heat -- connected by directed edges showing causal relationships. Each edge is labeled with "+" (amplifying) or "-" (dampening) to indicate the direction of influence.

Three major feedback loops are color-coded for clarity: the ice-albedo feedback (blue), the permafrost-methane feedback (brown), and the water vapor feedback (gray). Students can click buttons to highlight individual loops and trace the chain of cause and effect step by step, building a deep understanding of how each mechanism amplifies warming.

The "Trigger Warming" button starts an animation showing how an initial temperature increase cascades through all three feedback loops simultaneously, demonstrating why climate scientists are concerned about tipping points and runaway warming. This systems-thinking approach helps students understand that climate change is not a simple linear process but a complex web of reinforcing interactions.

How to Use

  1. Examine the network diagram showing climate variables as nodes and causal relationships as directed edges.
  2. Click the Ice-Albedo button to highlight and trace the ice-albedo feedback loop (blue): warming reduces ice, which reduces reflectivity, which increases solar absorption, which causes more warming.
  3. Click the Permafrost button to highlight the permafrost-methane feedback loop (brown): warming thaws permafrost, releasing stored methane, a potent greenhouse gas that causes more warming.
  4. Click the Water Vapor button to highlight the water vapor feedback loop (gray): warming increases evaporation, adding water vapor (a greenhouse gas) to the atmosphere, which traps more heat.
  5. Click All Loops to see all three feedback mechanisms displayed simultaneously.
  6. Click Trigger Warming to animate how an initial warming event cascades through all feedback loops.
  7. Hover over any node to see details about that climate variable.
  8. Click Reset to return the diagram to its default state.

Iframe Embed Code

You can add this MicroSim to any web page by adding this to your HTML:

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<iframe src="https://dmccreary.github.io/ecology/sims/climate-feedbacks/main.html"
        height="562px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Grade Level

9-12 (High School Environmental Science / Earth Science)

Duration

40 minutes

Learning Objectives

  • Trace how positive feedback loops in the climate system amplify warming
  • Diagram the causal chain in the ice-albedo, permafrost-methane, and water vapor feedback loops
  • Distinguish between positive (amplifying) and negative (dampening) feedback in Earth systems
  • Explain why feedback loops make climate change projections more uncertain and potentially more severe

Prerequisites

  • Basic understanding of the greenhouse effect and greenhouse gases
  • Familiarity with the concept of albedo (reflectivity)
  • Knowledge of the difference between weather and climate

Standards Alignment

  • NGSS 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.
  • NGSS 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.
  • AP Environmental Science: Topic 9.4 -- Global Climate Change

Activities

  1. Engage (5 min): Present the analogy of a microphone too close to a speaker creating audio feedback. Ask students to define feedback in their own words. Introduce the concept of positive vs. negative feedback loops in natural systems.

  2. Explore (15 min): Students work through each feedback loop individually using the highlight buttons. For each loop, students trace the causal chain and write it as a sequence (e.g., Temperature rises --> Ice melts --> Albedo decreases --> Solar absorption increases --> Temperature rises further). Then click "Trigger Warming" to observe the cascade effect.

  3. Explain (10 min): Class discussion connecting the feedback loops to real-world observations. Why is the Arctic warming faster than the rest of the planet? What are the implications of permafrost thawing across Siberia and Alaska? Introduce the concept of tipping points -- thresholds beyond which feedback loops may become self-sustaining regardless of human emissions reductions.

  4. Extend (10 min): Students draw their own causal loop diagram for a negative (stabilizing) feedback loop in the climate system (e.g., increased plant growth absorbing more CO2 as temperatures rise). Compare the strength of positive vs. negative feedbacks and discuss which dominate in the current climate trajectory.

Assessment Questions

  1. Trace the ice-albedo feedback loop step by step. Why is this considered a positive feedback loop?
  2. Permafrost contains an estimated 1,500 gigatons of carbon. Explain why thawing permafrost is a concern for climate scientists even if all human emissions stopped today.
  3. How does the water vapor feedback differ from CO2 forcing? Why is water vapor considered a feedback rather than a forcing?
  4. What is a climate tipping point, and how do positive feedback loops relate to this concept?
  5. Draw a causal loop diagram for a negative feedback loop in the climate system. Explain why negative feedbacks alone are insufficient to prevent warming.

References

  1. IPCC (2021). Climate Change 2021: The Physical Science Basis. Chapter 7: The Earth's Energy Budget, Climate Feedbacks, and Climate Sensitivity.
  2. Lenton, T. M., et al. (2019). Climate Tipping Points -- Too Risky to Bet Against. Nature, 575, 592-595.
  3. NASA Global Climate Change. (2024). The Study of Earth as an Integrated System. climate.nasa.gov