Earth’s Energy Budget: The Greenhouse Effect and Climate Change

Introduction

Earth is like a giant house in space. It receives energy from the Sun, but it also has to release that energy back into space to stay at a stable temperature. If the amount of energy coming in is greater than the amount going out, the “house” gets warmer. This balance is known as Earth’s Energy Budget. In this investigation, you will use a simulation to manipulate the factors that control this budget and discover how small changes in our atmosphere can lead to big changes in our climate.

Part 1: Engage (Anchoring Phenomenon)

The average temperature of the Moon is about $-18^\circ\text{C}$ ($0^\circ\text{F}$), but the average temperature of the Earth is about $15^\circ\text{C}$ ($59^\circ\text{F}$), even though they are roughly the same distance from the Sun.

  1. Question: Why is Earth so much warmer than the Moon?
  2. Prediction: If we added a giant mirror in space to reflect more sunlight away from Earth, what would happen to our global temperature?
  3. The Mystery: What role does the atmosphere play in “trapping” energy?

Part 2: Explore (Global Energy Lab)

Open the Greenhouse Effect Simulation. You will investigate the impact of four different variables on Earth’s climate.

Your Challenge:

Determine which variable has the strongest impact on “Outgoing Energy” and “Global Temperature”.

Procedural Steps:

  1. Baseline: Start the simulation with default settings (Solar: $340$, Albedo: $0.3$, CO2: $400\text{ ppm}$). Record the Global Temp after Year 10.
  2. Solar Variation: Increase Solar Intensity to $400\text{ W/m}^2$. Compare the “Incoming Solar” vs “Outgoing Energy” readouts.
  3. Albedo Test: High Albedo (Ice) vs Low Albedo (Ocean). Switch the surface type and observe how it affects the “reflection” of yellow photons (visible light) in the Microscopic View.
  4. The Greenhouse Effect: Increase CO2 to $800\text{ ppm}$. Switch to the Microscopic View and observe the path of the red photons (Infrared Heat). How do the CO2 molecules interact with them?

Data Collection:

| Factor Tested | Setting | Global Temp ($^\circ\text{C}$) | Incoming Solar vs Outgoing Energy | | :— | :— | :— | :— | | Baseline | $400\text{ ppm}$ CO2 | | | | Increased Solar | $400\text{ W/m}^2$ | | | | High Albedo | Ice | | | | High Greenhouse | $800\text{ ppm}$ CO2 | | |

Part 3: Explain (Sensemaking)

Analyze your findings to build a mechanistic model of climate.

  1. Mechanistic Account: Using the Microscopic View, describe the “journey” of a yellow solar photon vs a red infrared photon. Which one is affected by Greenhouse Gases?
  2. Energy Flow: When you increased CO2, did the “Incoming Solar” change? Did the “Outgoing Energy” change initially? Explain how this created an energy imbalance.
  3. Cause and Effect: Identify one factor that affects energy input and two factors that affect energy output.
  4. Net Effect: If the Sun’s intensity decreased slightly but we doubled the amount of CO2, could the temperature stay the same? Explain using your understanding of the “net effect” of competing factors.

Part 4: Elaborate/Evaluate (Critical Thinking)

Predicting Climate Shifts

  1. Feedback Loops: As Global Temperature rises, Arctic ice melts. Since ice has a high albedo (reflects light) and ocean has a low albedo (absorbs light), how will this melting affect the future temperature? Is this a positive or negative feedback loop?
  2. Cloud Mystery: Increase the Clouds setting to $100\%$. Does this warm or cool the planet in the simulation? Why?
  3. Policy Connection: Based on your simulation results, what is the most effective way for humans to stabilize Earth’s Energy Budget?

Part 5: Summary

Construct a simple “Energy Budget” diagram. Label: