In this activity, students look at a series of graphs showing global temperature and carbon dioxide levels to make the connection that the two are correlated. Then they watch a video about the greenhouse effect to see how carbon dioxide is causing global temperature increases. Finally, students fill in a cause & effect graphic organizer that traces each step from greenhouse gases to the sunny day floods in their phenomenon.

Approximate Time: 60 minutes

Objectives:

• Students will analyze graphs to identify the correlation between carbon dioxide concentrations in the atmosphere and global temperature increases

• Students will be able to explain the greenhouse effect in order to show how carbon dioxide is causing global temperature increases

Materials (see activity for details on these materials)

• Computer & projector

• Speakers for video

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Handouts:

• Rising Temperatures, Rising Tides

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DCI: ESS 3.D: Global Climate Change

SEP: Analyzing Data; Constructing Explanations

CCC: Cause & Effect; Patterns

Show students this video below from NASA showing how global temperatures have risen from 1880-2018.Try to keep the title of the video off the screen, and at the end, have students guess what they think the video is showing. Don’t tell students whether they are wrong or right: you will come back to this video later, so use this video as an opportunity to spark students’ curiosity about what they will be learning today.

Remind students that in their last activity, they learned that one of the causes of sea level rise is melting land ice (Antarctic ice and glaciers, largely in Greenland). But why is the ice melting in the first place? In today’s activity, they are going to study why the ice is melting. If any students posted a question about climate change or global warming in Activity 1, tell them they will investigate the answers to those questions today.

Ask students what could cause the ice in Antarctica to melt. Students should say something about the temperature (ex. that it is too hot). Tell them that the first piece of evidence they should look at then is the temperature. Since ice is melting all over the planet, they will look at a graph of global temperature first.

Hand out the Rising Temperatures, Rising Tides sheet to students and have them look at the graph on the first page. You can also display the graph on the projector so they can see it in color.

Take a moment to help students understand what the graph is showing, then have them answer the questions below the graph.

Review just the final question with students to make sure they understand that global temperatures are rising. Then go back to the NASA visualization video and make sure students see the title and the scale in the top left. Show the video again so students see the two different ways to display similar data.

Have students look at the next graph and project it:

Have students answer the questions below the graph. Students will study the idea of parts per million in a later activity, but it is a good idea to mention to them that parts per million is a measurement that is similar to percent (parts per hundred). One part per million is the same as 0.0001%.

Have students look at the third graph and project it:

Have them answer the question below it.  You can review quickly afterwards, but students should have a good sense at this point that carbon dioxide levels and global temperature are correlated.

Have students read the short passage on correlation vs. causation. This topic is always tricky for students to grasp, so take the time to review it with students afterwards. The key point in this reading for students to take away is that the data looks like carbon dioxide might be causing the global temperature to go up, but as scientists we need an explanation of why.

Show this video on the greenhouse effect from the US EPA:

Afterwards, have students turn to the next page in their handout so they can fill in the graphic. You can show the video a second time (it is short) to help students with the graphic. When they are done, discuss what they learned about the greenhouse effect. Key takeaways:

• The greenhouse effect is necessary to keep Earth warm enough for us to live

• The greenhouse effect works by trapping heat in Earth’s atmosphere

• Carbon dioxide is a greenhouse gas

• Humans produce extra carbon dioxide by driving cars and using energy

• Too many greenhouse gases are causing the Earth’s temperature to rise

Now that the class has made connections among sunny day flooding, rising ocean levels, melting ice, rising global temperatures, rising carbon dioxide levels, and the greenhouse effect, see if students can fill in the cause and effect organizer. Make sure students understand that the arrows mean one thing causes the following effect, which then causes the next effect. There are a variety of ways that students can fill it in; the key is to help students internalize the cause effect relationship from one step to another. A sample cause-effect organizer is below:

Make sure to return to the causation/correlation discussion to ask students if they think carbon dioxide concentrations and global temperature are only correlated, or if one is actually causing the other.

This cause and effect organizer helps to answer a lot of questions that students may have had during Activity 1, so go back to the questions board to see if there are any big questions you can answer now. If so, you may want to have students answer the question in place of the formative assessment below.

Using your cause and effect organizer, and what you’ve learned so far in this investigation, explain how extra greenhouse gases like carbon dioxide are causing the sunny day flooding in Annapolis.