Teaching Sequence

Work through this resource in the following sequence:

10 minutes

Tune In: What is a greenhouse gas?

30 minutes

Find Out: Investigating carbon and the carbon cycle

20+ minutes

Take Action: Actions for reducing CO₂

5 minutes

Reflection

Tune In: What is a greenhouse gas?

Step 1

In the previous lesson in this unit students learnt about the natural and enhanced greenhouse effects. Ask your students what is the greenhouse gas that gets the most attention, and do they know why this is the case?

Students might be able to name carbon dioxide but not be able to explain why it gets the most attention.

Step 2

Ask students to use their devices to explore the Greenhouse gas emissions page from Our World in Data. They can find a huge amount of data on this page, but ask them to focus on answering the questions below to help guide them

What trend do you notice with Total Greenhouse gas emissions?
What countries produce the most greenhouse gases?
What are the three main greenhouse gases?
As of 2021, what were the percentages of the three main greenhouse gas emissions?

If you want your students to delve a little more deeply into this, get them to look into the methane and nitrous oxide emissions information available on this page.

Step 3

After students have completed this research, ask again why carbon dioxide gets the most attention when it comes to greenhouse gas emissions.

Carbon dioxide is the most well-known greenhouse gas and plays an important role in trapping heat in our atmosphere. CO₂ emissions are the primary driver of climate change, they are the most abundant in the atmosphere and can linger in the atmosphere for thousands of years. Other greenhouse gases - such as methane and nitrous oxide - are also problematic, but in this lesson, students will be focusing on CO₂.

Find Out: Investigating carbon and the carbon cycle

Step 1

Show students the following image of the simplified carbon cycle, Explain that the carbon cycle, much like the water cycle, is a process in which carbon atoms from us, animals, plants, the air, ocean, soil, etc. travel between different systems on Earth.

Source: https://www.sciencefacts.net/carbon-cycle.html

Discuss their observations of the carbon cycle, and what it is representing. You may like to prompt them with the following:

Where is the carbon coming from?
Where is it going?
Is any new carbon being added? What does that tell you about carbon on Earth?
How do you think fossil fuels are formed?
Which parts of the cycle can be affected by human impacts?
Can you see any ways this cycle would have changed over time?

Step 2

To explore the answers to these questions, invite students to participate in a guided discussion around the following video using the timings and suggested questions and answers below to guide your discussion

Keep this video on your screen as you will return to it throughout the Find Out part of this lesson

Real World: The Carbon Cycle - Essential for Life on Earth (https://www.youtube.com/watch?v=hgFpvDNfXOk)

Timing and Question	Suggested answer
Start - 1:28 What is carbon, and why is it important?	Carbon atoms are described as one of the fundamental building blocks of all life on Earth, and the amount of Carbon that is stored in living things is enormous. Where is carbon stored? Share and discuss this image.
1:28 - 1:59 What is the carbon cycle?	The carbon cycle is a process that cycles carbon through our Earth and its atmosphere. "The carbon cycle is nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again." (Source)
2:00 -2:25 What is fast carbon?	The fast carbon cycle happens over years or decades. Plants absorb Carbon dioxide through photosynthesis. Before being released through respiration, this Carbon is used to build cells, proteins and DNA molecules within the plant. When the plant dies, microorganisms break down the dead plant material, and in the process, the Carbon is released back into the atmosphere. (Source)
2:25 - 3:08 What is slow carbon?	The slow carbon cycle moves carbon very slowly between the atmosphere, lithosphere and the oceans. For example, as rocks are weathered, carbon can move from the atmosphere to the lithosphere by dissolving the rocks, which causes the run-off to flow into the sea, where it settles to the ocean floor as sediment. Over millions of years, the sea floor is compacted and turned into rock, which then gets pushed back up to the Earth's crust at fault lines between tectonic plates. Volcanoes then return this rock to the earth's surface, releasing the carbon into the atmosphere. (Source)

You might like your students to annotate the outcomes of your discussion onto the carbon cycle image on their student worksheet as you are working through the video.

Source; https://www.sciencefacts.net/carbon-cycle.html

Step 2

Conduct a discussion with your students using the following prompts:

What do you know about how humans are impacting the carbon cycle?
How might we affect the fast carbon cycle?
How might we affect the slow carbon cycle?
What might be the consequences of changes to the carbon cycle?

Step 3

Watch the carbon cycle video from the previous section from 3:08 to 3:52mins and reiterate to your students that we need plants to absorb and store CO₂. Land clearing removes important carbon stores and releases more CO₂ into our atmosphere. Likewise, burning fossil fuels that were buried deep underground also releases CO₂. This extra CO₂ in our atmosphere is enhancing the greenhouse effect and leading to global warming, which in turn is causing climate change.

Step 4

Explain to your students that many scientists all around the world are working hard to understand how humans are affecting the carbon cycle and how this is contributing to climate change. One of the tasks that some scientists need to do is to understand how much CO₂ is being added to the atmosphere through human activity. They do this by calculating how many metric tons of CO₂ are being released and what the concentration of CO₂ in the atmosphere is.

Optional for students requiring extension

What might be some potential issues in accurately measuring how much carbon dioxide is being released into the atmosphere?

Carbon dioxide is an invisible gas! However, there are a number of techniques that can be used, for example (work through the examples that you feel are most relevant to your students - you could work through them as a class or assign sources to groups of students to examine)

1	Using historical data from ice cores to tell us about how CO₂ levels have changed over time to understand more about the changes we are experiencing now, for example, in this video.
2	Looking at where carbon is being stored now, for example, in trees. Return to this video, and start the video at 03:52 and watch to the end.
3	Examining the concentration of CO₂ in the air, for example, in this video. We can use this information to record the level of CO₂ as PPM (parts per million). Note: the scientist in this video is the son of Charles David Keeling who was the first person to begin systematic measurements of atmospheric CO₂ in 1956. His data was used as a graph to demonstrate the rise of CO₂ levels in our atmosphere. This graph is known as the Keeling Curve.

Take Action: Actions for reducing CO₂

Step 1

Pose the question to your students - why might we want to know about the amount of CO₂ being released into our atmosphere?

Invite students to suggest answers and explain that knowing about CO₂ levels and the human activities that generate the most CO₂ can tell us how to reduce the emissions being released into the atmosphere.

Step 2

Students will now explore actions to reduce their personal CO₂ emissions. Share the following graph with students (also available on the Student Worksheet):

Students will investigate 5 or more actions (depending on time and ability), conducting research into why this action would prevent emissions and what this action could look like in practice (e.g. reducing food waste = eating dinner leftovers for lunch and sticking to a list when at the supermarket). They can then create their own infographic with these actions and the associated research they have conducted.

Consider:

Reflection

Students can work independently to respond to the following:
Which actions for reducing CO₂ stand out to you the most and why? Select 2.

Climate Science: The Issue With Carbon

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Summary

Lesson Guides and Printables

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