Week 2: Feedback Loops

Grade 7 Science | Rosche

Text-to-Speech: Chrome (Right-click → "Read aloud") | Edge (Icon in address bar)
Need Support?: Look for green and red "Hint" and "Walkthrough" boxes!

Chromebook Tips

  • Auto-save: Forms save when you click outside text boxes
  • Order: Hook → Stations 1-3 → Exit
  • Builds on Week 1: CO₂ molecular vibration concepts
  • Key: Positive feedback = amplifies change; Negative = stabilizes

🌡️ NGSS Standards Covered This Week

MS-ESS3-5 (Continuing from Week 1)

What it means: Ask questions to clarify evidence of the factors that have caused the rise in global temperatures over the past century.

In student language: I can explain how feedback loops accelerate climate change.

Spiral Standards from Week 1 & Cycle 2

  • Week 1: CO₂ absorbs IR and vibrates (greenhouse effect)
  • Week 1: Carbon cycles through Earth systems
  • MS-PS1-5: Atoms are conserved in reactions

How These Connect (3-Dimensional Learning)

Dimension What You'll Practice
SEP-2 Developing Models Model positive feedback loops
DCI ESS3.D Human Impacts Understand how feedback amplifies change
CCC Stability & Change Identify when systems shift to new equilibria

🎯 Learning Targets

By the end of this week, you will be able to:

Success Criteria – How You'll Know You've Got It

Target 1: Explain how albedo affects Earth's energy balance

Self-check: Can I predict which surfaces will heat up faster based on their color?

Target 2: Model a positive feedback loop using ice-albedo as example

Self-check: Can I draw a loop showing how melting ice causes more melting?

Target 3: Analyze carbon sink data and predict consequences of saturation

Self-check: Can I explain what happens when oceans absorb less CO₂?

Target 4: Design a carbon capture system using scientific principles

Self-check: Can I calculate how much CO₂ my design would capture?

🧊 The Phenomenon: The Melting Ice Mystery

Scientists have discovered something strange about Arctic ice:

  • When ice starts melting, it doesn't just melt at a steady rate
  • Instead, melting SPEEDS UP over time
  • The more ice that melts, the FASTER the remaining ice melts

This seems backwards! Why would less ice = faster melting?

🤔 Driving Question: Why might melting ice cause MORE melting? What creates this accelerating cycle?

Key Vocabulary This Week

Term Definition
Albedo The fraction of light a surface reflects (0 = absorbs all, 1 = reflects all)
Positive Feedback When change causes MORE of the same change (amplifying loop)
Negative Feedback When change causes the OPPOSITE change (stabilizing loop)
Carbon Sink A reservoir that absorbs more carbon than it releases (oceans, forests)
Tipping Point The threshold where a system shifts to a new, hard-to-reverse state

🎯 Practice These Vocabulary Terms

🎯 Hook – The Melting Ice Mystery

12 Points | ~10 Minutes

Tasks (~10 min)

  1. Observe the phenomenon: accelerating ice melt (2 min)
  2. Make predictions about WHY melting speeds up (3 min)
  3. Learn about feedback loops (3 min)
  4. Connect to Week 1 greenhouse effect (2 min)
▼ 🧊 Step 1: Observe the Phenomenon (Click to expand) ▼

Click "Start Observation" below and watch the Arctic ice over 50 years. Pay close attention to the melt rate — does it stay the same, or does it change?

Your Simulation Summary
Your prediction: —
Trial results: —
Average result: —

Think About This:

  • What color is ice? What color is ocean water?
  • Which absorbs more sunlight - white surfaces or dark surfaces?
  • How does this connect to what you learned about CO₂ and heat in Week 1?

📝 HOOK FORM

☀️ Station 1 – Albedo Effect Investigation

20 Points | ~18 Minutes

ALBEDO = the fraction of light that a surface REFLECTS

  • Albedo of 0 = absorbs ALL light (black)
  • Albedo of 1 = reflects ALL light (perfect mirror)
  • Snow ≈ 0.8-0.9 (reflects most)
  • Ocean ≈ 0.06 (absorbs most)

Your Digital Investigation:

  • Use the Ice-Albedo Feedback Simulator below to explore how different surfaces absorb heat
  • Analyze the reference data table showing how surfaces with different albedos heat up
  • Connect your findings to explain why melting ice accelerates warming

Reference Data: How Different Surfaces Heat Up

This data shows what happens when light hits surfaces with different albedos:

Surface Albedo Start Temp After 3 min Change
Black surface (like ocean) ~0.06 22°C 38°C +16°C
Water ~0.10 22°C 31°C +9°C
White surface (like clouds) ~0.70 22°C 27°C +5°C
Ice/Snow ~0.85 22°C 24°C +2°C

Key Insight: Low albedo surfaces (dark) absorb more light and heat up faster. High albedo surfaces (light) reflect light and stay cooler.

▼ 🧊 Interactive: Ice-Albedo Feedback Simulator (Click to expand) ▼

See the feedback loop in action! Watch how melting ice creates a positive feedback loop: less ice → lower albedo → more heat absorbed → more melting → even less ice...

▼ 📗 Need extra support? Click here for hints and sentence starters ▼

Key Concept Reminder:

  • Albedo = how much light bounces OFF a surface
  • HIGH albedo (like snow) = reflects light = stays COOL
  • LOW albedo (like ocean) = absorbs light = gets HOT

Sentence Starters for Question 3:

  • "Black paper heated the most because its albedo is low, which means..."
  • "Surfaces with high albedo, like aluminum foil, stayed cooler because..."
  • "The data shows that darker surfaces absorb more _____ energy, causing..."

Word Bank:

reflects • absorbs • albedo • light energy • temperature • feedback • amplify • positive feedback

▼ 🆘 Stuck? Click here for step-by-step help ▼

Try these steps in order:

  1. Re-read the albedo definition in the orange box above
  2. Look at your data: Which surface had the BIGGEST temperature change?
  3. Ask yourself: Was that surface light-colored or dark-colored?
  4. Check the vocabulary table at the top of the page
  5. Watch a 2-min review: Search "What is albedo simple"
  6. Still stuck? Post in Canvas Discussion: "W2 Help Thread"
  7. Email Mr. Rosche: Include your specific question

📝 STATION 1 FORM

🌊 Station 2 – Carbon Sink Analysis

20 Points | ~15 Minutes

Global Carbon Budget (gigatons CO₂/year)

SOURCES Gt/year
Fossil fuels +36
Deforestation +5
Total Emitted 41
SINKS Gt/year
Ocean absorption -10
Land/forest absorption -12
Total Absorbed 22

REMAINING IN ATMOSPHERE: 41 - 22 = 19 Gt/year

▼ 🌍 Interactive: Carbon Sink Simulator (Click to expand) ▼

Explore what-if scenarios! Adjust emission levels and forest coverage to see how carbon sinks respond. What happens when sinks become saturated?

📝 STATION 2 FORM (Calculator needed)

🔧 Station 3 – Engineering Carbon Capture

25 Points | ~20 Minutes (Highest Value!)

Design a Carbon Capture System for Our School!

CONSTRAINTS:

  • Must work at school scale (not industrial)
  • Must be sustainable (low energy input)
  • Must store carbon for at least 10 years
  • Budget: $500 maximum

Carbon Capture Options:

Approach Method Cost
Tree planting ~48 lbs CO₂/tree/year $10-50/tree
Algae cultivation 10x faster than trees $100+ setup
Composting Stores carbon in soil $50 bins
Solar panels Prevents new emissions $$$

📝 STATION 3 FORM

🎓 Exit Ticket – Feedback Loop Integration

23 Points | ~15 Minutes

Question Types:

  • 2 NEW - Week 2 feedback loop content
  • 2 SPIRAL - Week 1 + Cycle 2 review
  • 1 INTEGRATION - Connect Week 1 & Week 2
  • 1 SEP-2 - Create a feedback loop model

📝 EXIT TICKET

Week 2 Summary: What You Learned

Albedo Effect: White surfaces reflect light (stay cool), dark surfaces absorb light (heat up)

Positive Feedback: Change that causes MORE of the same change (amplifying loop)

Carbon Sinks: Reservoirs that absorb CO₂ - can become saturated

Multiple Feedbacks: Climate change involves many interacting feedback loops

🎉 Week 2 Complete!

Next Week: Synthesis & Assessment - Bringing it all together!

👇 🌟 Enrichment & Extension 👇
Optional deep dives for early finishers.

Optional content if you finish early or want to go deeper.

👨‍⚠️ Scientist Spotlight

Research a scientist who contributed to this week's topic area and describe their key findings.

⚖️ Environmental Justice Connection

Explore how this week's science concepts connect to environmental justice issues in our community.

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