1. Activate students' prior knowledge about reflection and absorption.

Show the photos of the Bear Glacier in Alaska (1909 and 2005). Tell students that some surfaces reflect light more than others and that more reflective surfaces have a higher albedo. Ask:

• Which photo shows surfaces with higher albedo? (The 1909 photo shows surfaces with a higher albedo. There is more snow and ice in that photo than in the 2005 photo.)
• Which photo shows surfaces that would absorb the most solar radiation? (The 2005 photo shows surfaces that would absorb the most solar radiation. The ice and snow in the 1909 photo would reflect most of the solar radiation.)
• Why does a dark-colored surface feel much hotter than a light-colored surface in the sunshine? (The dark-colored surface absorbs more radiation than the light-colored surface. The absorbed radiation becomes heat energy in the surface.)

2. Discuss the role of uncertainty in the scientific process.

Tell students that science is a process of learning how the world works and that scientists do not know the “right” answers when they start to investigate a question. Let students know they can see examples of scientists' uncertainty in climate forecasting.

Show the Global Temperature Change Graph from the 1995 IPCC (Intergovernmental Panel on Climate Change) report and tell them that this graph shows several different models of forecast temperature changes. Ask: Why is there more variation (a wider spread) between the models at later dates than at closer dates? (There is more variation between the models at later dates than at closer dates because there is more variability in predicting the far future than in predicting the near future.)

Tell students that the ability to better predict near-term events occurs in hurricane and tropical storm forecasting as well. Project The Definition of the National Hurricane Center Track Forecast Cone and show students the “cone of uncertainty” around the track of the storm. The cone shows the scientists' uncertainty in the track of the storm, just as the climate models show the scientists' uncertainty in how much Earth's temperature will change in the future. Ask: When are scientists most confident in their predictions? (Scientists are most confident in their predictions when they have a lot of data. This is why the forecast for near-term events is better than forecasts of longer-term events, both in storm forecasting and in climate forecasting.)

Tell students that they will be asked questions about the certainty of their predictions and that they will need to think about what scientific data are available as they assess their certainty with their answers. Encourage students to discuss the scientific evidence with each other to better assess their level of certainty with their predictions.

3. Discuss the role of systems in climate science.

Tell students that forecasting what will happen in Earth's climate system is a complicated process because there are many different interacting parts. Scientists think about how one part of the system can affect other parts of the system. Give students a simple example of a system, as described in the scenario below.

On an island, there is a population of foxes and a population of rabbits. The foxes prey on the rabbits. Ask:

• When there are a lot of rabbits, what will happen to the fox population? (It will increase because there is an ample food supply.)
• What happens to the fox population when they’ve eaten most of the rabbits? (The foxes will die of starvation as their food supply decreases.)
• What happens to the amount of grass when the fox population is high? (The amount of grass will increase because there are fewer rabbits to eat the grass.)
• If there is a drought and the grass doesn’t grow well, what will happen to the populations of foxes and rabbits? (The rabbit population will decrease because they have a lesser food supply. The fox population should also decrease as their food supply decreases.)

Humans introduce dogs to the island. The dogs compete with the foxes over the rabbit food supply. Ask: What will happen to the populations of foxes, rabbits, and grass after the dogs are introduced? (The foxes will decrease because they are sharing their food supply, the rabbits will decrease because they have more predators, and the grass will do well because of the lowered impact of the smaller rabbit population.)

Tell students that they will be exploring cause-effect and system feedback relationships between carbon dioxide and water vapor in this activity. Ask students to think about how each piece of the system affects other pieces of the system.

4. Introduce and discuss the use of computational models.

Introduce the concept of computational models, and give students an example of a computational model that they may have seen, such as forecasting the weather. Project the NOAA Weather Forecast Model, which provides a good example of a computational model. Tell students that:

• scientists use information about the past to build their climate models.
• scientists test their climate models by using them to forecast past climates.
• when scientists can accurately forecast past climates, they can be more confident about using their models to predict future climates.

5. Have students launch the Feedbacks of Ice and Clouds interactive.

Provide students with the link to the Feedbacks of Ice and Clouds interactive. Divide students into groups of two or three, with two being the ideal grouping to enable sharing computer workstations. Tell students they will be working through a series of pages of models with questions related to the models. Ask students to work through the activity in their groups, discussing and responding to questions as they go.

NOTE: You can access the Answer Key for students' questions—and save students' data for online grading—through a free registration on the High-Adventure Science portal page.

Tell students this is Activity 5 of the lesson What is the Future of Earth's Climate?

6. Have students discuss what they learned in the activity.

After students have completed the activity, bring the groups back together and lead a discussion focusing on these questions:

• What is the relationship between ice cover and temperature? (When there is a lot of ice cover, the temperature is low. This is because the solar radiation is reflected into space rather than absorbed.)
• Is this model (Model 7) realistic? (The model is realistic, but it is not complete. Clouds can have cooling effects or warming effects depending on the location and makeup of the clouds. This model only shows high clouds that reflect sunlight back into space.)
• What would happen to ice cover if greenhouse gas concentrations increase? (Ice cover would decrease. This is because greenhouse gases trap heat energy in the atmosphere, causing the ice to melt because of the increased temperature. As the ice melts, more radiation is absorbed because there are fewer light-colored surfaces to reflect the radiation, leading to further warming.)
• What type of feedback is the relationship between clouds and temperature? (This is a negative feedback relationship. The cloud cover increases with increasing water vapor, but the cloud cover serves to reduce incoming solar radiation which leads to cooling. The stimulus is counteracted by the response.)
• What type of feedback is the relationship between ice and temperature? (This is a positive feedback relationship. The melting ice leaves a darker surface that absorbs more solar radiation, leading to more heating, leading to more melting. The stimulus is reinforced and accelerated by the response. Similarly, when the temperature is cold, more ice forms, which reflects more solar radiation, which leads to less heat absorption, which leads to further ice formation.)

### Informal Assessment

1. Check students' comprehension by asking them the following questions:

• How do ice, snow, and clouds affect temperature?
• Why is it colder on clear nights than on cloudy nights?
• If the sea ice melts, how might that affect global temperature and the atmospheric concentrations of carbon dioxide and water vapor?

2. Use the answer key to check students' answers on embedded assessments.

#### Subjects & Disciplines

• Earth Science

#### Learning Objectives

Students will:

• explain why light-colored surfaces have a cooling effect on Earths' temperature
• describe the positive feedback loop between temperature and ice cover
• describe the negative feedback loop between cloud cover and temperature
• describe the uncertainty about the feedbacks of temperature, water vapor, and cloud cover that complicate scientists' ability to predict future climate conditions

#### Teaching Approach

• Learning-for-use

#### Teaching Methods

• Discussions
• Multimedia instruction
• Visual instruction
• Writing

#### Skills Summary

This activity targets the following skills:

### Connections to National Standards, Principles, and Practices

#### ISTE Standards for Students (ISTE Standards*S)

• Standard 3:  Research and Information Fluency
• Standard 4:  Critical Thinking, Problem Solving, and Decision Making

### What You’ll Need

#### Required Technology

• Internet Access: Required
• Tech Setup: 1 computer per classroom, 1 computer per learner, 1 computer per small group, Projector

#### Physical Space

• Classroom
• Computer lab
• Media Center/Library

#### Grouping

• Heterogeneous grouping
• Homogeneous grouping
• Large-group instruction
• Small-group instruction

### Background Information

Solar radiation consists of visible light, infrared radiation (heat), and ultraviolet radiation. When solar radiation encounters Earth's atmosphere and surface, it can be reflected (sent back into space) or absorbed. Energy that is absorbed becomes heat in Earth's surface. This heat can be re-radiated into space. Light-colored surfaces reflect more solar energy than dark-colored surfaces.

Infrared radiation is emitted by Earth's surface. Instead of the infrared radiation being allowed to exit Earth's atmosphere into space, greenhouse gases absorb it and re-emit it, keeping more heat in the atmosphere. Greenhouse gases include carbon dioxide, methane, and water.

Clouds can have a cooling effect or a warming effect, depending on their makeup and position in the atmosphere. High-level clouds have a net cooling effect as they reflect incoming solar radiation. Low-level clouds have a net warming effect as they prevent infrared radiation from escaping into space.

• None

### Vocabulary

absorb
Verb

to soak up.

albedo
Noun

scientific measurement of the amount of sunlight that is reflected by a surface.

Noun

layers of gases surrounding a planet or other celestial body.

carbon dioxide
Noun

greenhouse gas produced by animals during respiration and used by plants during photosynthesis. Carbon dioxide is also the byproduct of burning fossil fuels.

Noun

all weather conditions for a given location over a period of time.

emit
Verb

to give off or send out.

Noun

phenomenon where gases allow sunlight to enter Earth's atmosphere but make it difficult for heat to escape.

greenhouse gas
Noun

gas in the atmosphere, such as carbon dioxide, methane, water vapor, and ozone, that absorbs solar heat reflected by the surface of the Earth, warming the atmosphere.

ice core
Noun

sample of ice taken to demonstrate changes in climate over many years.

Noun

part of the electromagnetic spectrum with wavelengths longer than visible light but shorter than microwaves.

model, computational
Noun

a mathematical model that requires extensive computational resources to study the behavior of a complex system by computer simulation.

parts per million (ppm)
Plural Noun

A unit of measure of the amount of dissolved solids in a solution in terms of a ratio between the number of parts of solids to a million parts of total volume.

Noun

energy, emitted as waves or particles, radiating outward from a source.

system
Noun

collection of items or organisms that are linked and related, functioning as a whole.

Noun

degree of hotness or coldness measured by a thermometer with a numerical scale.

Articles & Profiles

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Reference

### Funder

This material is based upon work supported by the National Science Foundation under Grant No. DRL-1220756. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.