Feedback of Ice and Clouds
Lesson 9 of 10
Objective: SWBAT explain the albedo effect, describe positive and negative feedback loops; and identify the uncertainty about feedback loops and scientists ability to predict future climate conditions.
This is the fourth of five modules on climate change from the Concord Consortium, What is the Future of Earth's Climate. You could choose to follow the modules in the order presented if you like. I chose to break them apart to fit into the flow of my unit on climate change.
By using interactive computational models, students explore how light-colored surfaces such as snow, ice, and some clouds have a cooling effect on Earth. Then they interpret real world data to examine the positive feedback loop between ice coverage and temperature.
Students will be able to:
- 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
The website says that each module should take about 45 minutes to complete. My students have not needed this much time. 35 minutes is more realistic. I would recommend planning on time to debrief and discuss each module in which case you could spend an entire 50-55 minute class per module.
I have attached the Portal User Guide to setting up a teacher account and creating a class for your reference.
In addition, What will be Earth's climate in the future? has a teacher guide.
The modules address the Science and Engineering Practices (NGSS) as well as the Crosscutting Concepts.
Science and Engineering Practices:
1. Asking questions (for science) and defining problems (for engineering)
2. Developing and using models
3. Planning and carrying out investigations
4. Analyzing and interpreting data
5. Constructing explanations (for science) and designing solutions (for engineering)
6. Engaging in argument from evidence
7. Obtaining, evaluating, and communicating information
2. Cause and effect: Mechanism and explanation
3. Scale, proportion, and quantity
4. Systems and system models
5. Energy and matter: Flows, cycles, and conservation
7. Stability and change
In addition to the following disciplinary Core Ideas
ESS3.D: Global Climate Change
Human activities, such as the release of greenhouse gases from burning fossil fuels, are major factors in the current rise in Earth’s mean surface temperature (global warming). Reducing the level of climate change and reducing human vulnerability to whatever climate changes do occur depend on the understanding of climate science, engineering capabilities, and other kinds of knowledge, such as understanding of human behavior and on applying that knowledge wisely in decisions and activities. (MS-ESS3-5)
- computers with internet access
To get started, give your students some background on the purpose of these modules.
I like to show them a before and after picture of a glacier that has undergone a tremendous amount of retreat. A quick Google search of "glacier before and after" will give you plenty of images to select from. Perhaps you already have some images you like?
Here is one from the Upsala Glacier in Argentina.
Use the images to derive some responses to the question:
What could be some of the causes for this amount of glacial retreat?
Ask students to brainstorm a list of ideas in their journal and then turn and talk to a neighbor. Bring the class back together and call on a few students to hear their ideas.
Have your students get computers and login into the website. I created the Activity 4- Feedback of Ice and Clouds handout to help in walking students through the process of logging in and starting the module.
In the module, they explore the questions:
- How does solar radiation interacts with components of Earth's surface and atmosphere?
- How do greenhouse gases warm Earth's atmosphere?
Using interactive computational models, students explore how light-colored surfaces such as snow, ice, and some clouds have a cooling effect on Earth and interpret real-world data to observe the positive feedback loop between ice coverage and temperature.
They need 35-45 minutes to complete the activity. The site saves their work as they progress, so if they need to stop and start on a second day or at home, their work is not lost.
When students are finished with the investigation, have them summarize what they learned on the Earth’s Energy Budget page. This includes a review of vocabulary terms along with creating a visual of the interaction of systems.
I use the powerpoint Glacial Retreat and Sea Level Rise to summarize and explain the concepts covered in this lesson.
Students may complete the computer activity at different times, so you can have the Arctic Climate Feedback Loops Student Handout ready to complete or if you like wait and start it with all the class after completing the summary.
In this activity students will read the background text Arctic Climate: A Systems View and identify the key variables in each of the two feedback loops in the essay and re-create the feedback diagrams.
Key variables should be able to clearly increase or decrease. They do not have to be countable, but you should be able to describe them with some “measure.” For example, a key variable might be “average concern about a warming climate.”
If your class is not familiar with feedback loops, guide them through this activity. Model how to identify the key variables, start a list in their journal, practice on their own.
Once they have a list of variables, guide the class through making a feedback loop. Discuss the parts and how they are connected.
Give them more practice by asking to work in pairs to make additional feedback loops. Handout the Arctic Climate Feedback Loops Student Page and ask them to work together to create a loop for each of the 4 examples. I use student white boards and markers at this time so them can share out to the class.
These materials have been adapted from Systems Literacy on PBS LearningMedia.
I tied this entire lesson together by showing students Climate Tipping Point (a larger feedback loop diagram) that brings together all the content we have been discussing up to this point.
Project the image, or make copies, and discuss with your class the complexity of the system. Look for connections back to what you have already discussed in class. Have them identify the reinforcing and balancing loops.
In the video below, two students share how building and talking about causal loop diagrams helped them understand the connections between elements in the story.