This is a group activity based on a class of 26-30 students. Depending on the group size, the numbers listed below may need altering. Guidance on specific changes is given in the Group size options section below.

Set up

Download the Carbon cycle role play cards from the What you’ll need section. Stick up the ‘team area’ cards on four walls of a classroom. Assign students to each of the team areas based on the numbers in the diagram below with:

• 6 in the atmosphere team
• 4 in the land plant team
• 2 in the land animal team
• 9 in the ocean
• 2 in the ocean plant team
• 1 in the ocean animal team
• 6 in the fossil fuel team

Activity steps

1. Tell students that they are going to behave like carbon moving around the planet over the past 750 years.
2. At the beginning of each turn, students will need to follow the instructions on the role play slides.
3. The Carbon cycle role play slides are set out to support movement in line with the five main process. This means carbon moves from the atmosphere to land plants, and the ocean to ocean plants first (photosynthesis). This is followed by plants to animals movement on land and in the ocean (consumption). Then respiration, with movement from plants and animals on land to the atmosphere, and from plants and animals in the ocean to the ocean. Last, carbon is exchanged between the atmosphere and ocean.
   
4. After this first round, you can check students’ understanding to see if they can describe why they have moved in the way they have. See the debrief section below for model student statements on what their movement is representing.
5. Repeat the movements between teams two more times, asking different students how they have moved and what this represents.
6. After all the other students have moved on the third round, it is the turn of the fossil fuel team to move.
7. Ask students what this represents and why students in the fossil fuel team had to wait until the final round to move. You may wish to emphasise that each round represents 250 years.
8. Students return to their seats. You may wish to show the Carbon cycle interactive (basic) at the front of the classroom to review any learning.

This activity offers a simplified version of the carbon cycle with only five processes being included. These five processes are:

1. Photosynthesis – plants absorb carbon (dioxide) from the atmosphere and use sunlight to combine this carbon with water to create sugars.
2. Respiration – plants and animals ‘burn’ sugars with oxygen and emit carbon (dioxide) and water.
3. Consumption – animals eat the carbon stored as food in plants and other animals.
4. Exchange – gases including carbon dioxide are exchanged between the ocean and the atmosphere.
5. Combustion – ancient plants and animals that have died and been buried over thousands of years form fossil fuels (oil, gas, and coal) under pressure. These fossil fuels are extracted and burned releasing carbon (dioxide) into the atmosphere.

Note: carbon dioxide is a form of carbon found as gas in the atmosphere. It is formed from one carbon atom and two oxygen atoms. It is most abundant of the greenhouse gases released by human activities. These greenhouse gases in the atmosphere responsible for trapping the sun’s warmth.

Of course, there are other processes at work too. Science teams are investigating everything from the rate at which carbon is absorbed into the ocean, to how worms ‘pull’ carbon into the soil and seabed sediments and store it away. More complex models of the carbon cycle can be viewed in the Carbon cycle interactive diagrams for lower secondary [linked] and upper secondary [linked] students.

The amount of carbon in different parts of our planet are known as stores. The most simplified version of these stores divides the planet into four parts or spheres:

1. Atmosphere – the gases surrounding the planet (from the Greek for gas atmos and ball sphaira)
2. Hydrosphere – all the watery parts of our planet from streams and clouds to the ocean (from the Greek for water hydor)
3. Biosphere – all the living things on our planet from plants and animals to fungi and bacteria (from the Greek for life bios)
4. Lithosphere – the rocky part of the planet from soils and sediments to fossil fuels and cliffs (from the Greek for rocks lithos)

The movement of carbon between these stores or spheres are known as fluxes. Carbon in stores is measured in GtC or Gigatonnes of carbon. Fluxes are measured in GtC/yr, the amount of carbon that moves on an annual basis.

These stores and fluxes are represented very approximately in this activity, but the key points in terms of numbers are:

• Historically, the amount of carbon absorbed (113 GtC/yr) and emitted (111.1 GtC/yr) by land plants and animals are roughly equal.
• Historically, the exchange between the ocean and the atmosphere has been roughly stable with 54.6 GtC/yr absorbed into the ocean, and 54.6 GtC/yr released.
• Human activity has increased carbon levels in the atmosphere by about 50 per cent from 591 GtC to the current levels of 870 GtC.
• The surface ocean contained 900 GtC (with a total ocean store of a huge 38,700 GtC). An additional 173 GtC of carbon has been added to the ocean since the Industrial Revolution.

For the activity, the number of students moving around the classroom has been altered to make it a little more fun, with more students moving than staying in the same place.

See the carbon stores and fluxes interactive for a more detailed diagram with up-to-date figures.