# Ice-Albedo Feedback Loop Task

**Standards Alignment:**
*   **Performance Expectation:** HS-ESS2-2
*   **Science and Engineering Practice:** Developing and Using Models
*   **Disciplinary Core Ideas:** ESS2.A: Earth Materials and Systems; ESS2.D: Weather and Climate
*   **Crosscutting Concept:** Stability and Change

**Simulation Link:** [Ice-Albedo Feedback Loop](IceAlbedoFeedback.html)

## Introduction

Earth's climate system is complex, driven by the interactions between the atmosphere, hydrosphere, cryosphere, lithosphere, and biosphere. One critical mechanism that can amplify changes within this system is a **positive feedback loop**.

In this task, you will use the **Ice-Albedo Feedback Loop** simulation to investigate how a single change—an increase in greenhouse gas forcing—can trigger a cascade of events that dramatically alters Earth's climate.

## Part 1: Initial State and Albedo

1.  **Observe the Equilibrium State:**
    *   When you first open the simulation, do not start it yet. Record the initial values for:
        *   Global Temperature: ______ °C
        *   Average Albedo: ______
        *   Ice Coverage (from the chart's y-axis, approximately): ______ %
    *   Read the "Log Panel". What does "System initialized at equilibrium" mean in terms of incoming solar radiation and outgoing heat?

2.  **Define Albedo:**
    *   Based on the "Understanding the Feedback Loop" section (located below the simulation model), what is albedo?
    *   Which surface has a higher albedo: ice/snow or ocean water?

## Part 2: Introducing a Change (The Trigger)

1.  **Adjust the Forcing:**
    *   Set the "Initial GHG Forcing" slider to "Moderate (+2 W/m²)". This represents an increase in greenhouse gases, which trap more heat in the atmosphere.
    *   Click "Start Simulation".
    *   Observe the "Global Temp" and "Avg Albedo" displays, as well as the log panel.

2.  **Data Collection:**
    *   Allow the simulation to run for several "Years" (x-axis on the chart).
    *   Pause the simulation when the Ice Coverage reaches approximately 10% (between 8% and 12%).
    *   Record the current values:
        *   Time (Years): ______
        *   Global Temperature: ______ °C
        *   Average Albedo: ______

3.  **Analyze the Initial Change:**
    *   What happened to the global temperature immediately after you increased the GHG forcing?
    *   As the temperature rose, what happened to the ice caps in the "Earth System Model" visualization?

## Part 3: The Feedback Loop in Action

1.  **Observe the Feedback:**
    *   Resume the simulation and let it run until all the ice melts.
    *   As the ice melted, what happened to the "Avg Albedo" value? Why?
    *   According to the log panel, what effect does a decreased albedo have on the rate of warming?

2.  **Graph Analysis:**
    *   Look at the "System Dynamics" chart. Describe the shape of the "Global Temp" curve. Is it a straight line (constant rate of change) or does it curve upward (accelerating rate of change)?
    *   How does the shape of the temperature curve relate to the decreasing "Ice Coverage" curve?

## Part 4: Constructing an Explanation

Using the evidence you gathered from the simulation, construct an explanation of the Ice-Albedo feedback loop.

Your explanation must include:
*   A description of the **initial trigger** (the change that started the process).
*   An explanation of how melting ice changes Earth's overall **albedo**.
*   A description of how this change in albedo affects the amount of solar energy absorbed by Earth.
*   A conclusion stating whether this is a **positive or negative feedback loop**, and how it affects the overall stability of Earth's climate system.