In this lesson, students will get a hands-on look at the carbon cycle, where carbon is stored in their local environment (organic matter), the importance of carbon as the building blocks of all life, how humans have an influence on the natural process of carbon cycling, and the importance of native Oak trees. Students will learn how we can help balance the carbon cycle by planting more trees.
- What effect do trees have on the air? (Cause & Effect; Obtaining, Evaluating, and Communicating information).
- How does the carbon found in plants and animals get into the air? (Energy & Matter; Obtaining, Evaluating & Communicating Information)
- What things do people do that can change the carbon cycle and make it less stable? (Stability & Change; Asking Questions & Defining Problems)
Human Impact - The effect our human actions have on the environment
Carbon Cycle/Emissions - The process of how carbon travels from nonliving to living things, often carbon can be left in the air surrounding the earth.
Biosphere - All parts of and around the earth where life can be found
Atmosphere - The layer of gas or air that surrounds the earth
Fossil Fuels - A natural substance that comes from the decomposition of organic material buried in the earth, it can be used as a source of energy.
Oaks - A genus of tree (Quercus) with over 500 species.
Stoma - A tiny opening or pore found on the leaf of a plant from which gas can come in and out.
Dendrochronology - The study of tree rings.
- One Carbon ‘Cookie’ per student (ie. Rocks or natural objects like acorns or wooden chips)
- Tree Cross Sections Images or real tree cross sections showing the individual circles. If you have tree stump seating in your garden, use these!
- Carbon Cycle Role Play Cards
- Carbon Cycle Script Lines (cut the script lines out for each group)
- Chalk to label areas if doing role play outside: atmosphere, land, and ocean
- Soil and pots for planting (optional)
- Gathered and stored oak acorn varieties (optional)
- Print out the Carbon Role Play cards and/or Carbon Cycle Script lines.
- Locate your Carbon cookies
- Gather acorns and planting materials (optional)
- Select space outside and label your categories (atmosphere, land and ocean)
- Be familiar with a basic version of the carbon cycle so you can draw it for students. Or have a diagram ready to go!
Engage: Breathe in (that is oxygen!) Breathe out (that is carbon dioxide!) Say what? Carbon is an element on Earth and is a building block to all Life. Do you know who breathes in what you breathe out? Trees! That’s right, trees and other plants breathe in carbon dioxide. Carbon dioxide, or CO2, is a molecule of carbon attached to two molecules of oxygen–plants breathe it in through tiny holes, or ‘stoma’, in their leaves and convert it to your favorite food–sugar–to store energy from the sun. At night, they break down the sugar and breathe out oxygen. So, plants and people breathe opposites!
Explore: Pass around tree cross sections for students to look at in groups (or look at a real-life cross section). Ask questions:
- How do scientists know what the weather was like in the past?
- How does climate affect tree growth?
- How do scientists measure changes in the climate through dendrochronology (study of tree rings)?
Scientists can study tree rings to tell when there were drier or wetter periods in time. In periods of drier climate the trees grow less.
What would the distance between the rings look like?
The rings are smaller and more compact.
During periods of time when there was a wetter climate, the trees grow more.
What would the distance between the rings look like then?
The rings would grow wider apart from more expansion.
Explain: This lesson is about oak trees AND carbon. Carbon is a natural element in our environment. It lives in everything that is living or was once living. Ask students to make educated guesses about things they think may contain carbon. Explain to your students that the carbon contained in any one thing doesn’t stay there forever. The carbon atoms move from one thing to another in what is called the carbon cycle. Parts of the carbon cycle happen very quickly, like when plants take in carbon dioxide from the atmosphere for photosynthesis. But, other parts of the carbon cycle happen very slowly. Draw a simple diagram of the carbon cycle and explain how the natural cycle is being disrupted by people adding more carbon to the atmosphere than ever before in human history. Talk about how fossil fuels and overgrazing contribute to this.
- Designate a large open space for this activity and introduce students to the three chalked-out or labeled categories ‘atmosphere’ ‘ocean’ and ‘land’
- Divide students evenly into 7 groups and distribute the appropriate role-play card and carbon cycle script lines to each group. Each group will be a team of actors that will play a certain part of the carbon cycle (atmosphere, water, algae, marine snail, sediments & rocks, trees, or land animals).
- Distribute 2-4 carbon ‘cookies’ to each group and explain that these represent carbon atoms.
- Have students in each group review their role play card to figure out their role in the carbon cycle and decide as a group using their “Options for carbon movement” how they are going to move their carbon.
- Explain that they can give their carbon to only one other group, or if they have plenty, they can give the carbon to more than one group.
- Explain that carbon exists in all of these things at the same time and only a portion of the carbon in each thing moves. Therefore, when each group moves their carbon, they can’t give away all their carbon: they must keep at least one carbon atom.
- As they move their carbon, they must say their script lines to explain the carbon movement that they have chosen.
- One at a time, ask each group to give their carbon to another group (or groups).
- Run the role-play a number of times, telling students to make different choices about carbon movement each time.
- If you have time, consider running the following variations: Have all the groups move their carbon at the same time: Have one person from each group be the deliverer of carbon and the other group members remain to receive carbon from other groups. Tell students that while this is more chaotic, it is a more realistic acting out of the carbon cycle, since in the real world carbon moves between all these areas at the same time. Trace the journeys of only a few carbon atoms: Use only one carbon atom (‘cookie’) and start it with one group. Each group that gets the atom makes a decision about where it goes next. Assign one student to write the journey on the board or a piece of paper. Do this multiple times so that you can compare the journeys of several individual atoms through the different spheres and see how the carbon cycle does not move only in one direction, but moves in lots of different directions at the same time.
- If time allows, lead an oak planting demonstration or activity
Reflect: So what has carbon in it? Why is carbon important? What do trees do that is so important? What happens if too much carbon gets in the atmosphere and there aren’t enough trees to remove it from the atmosphere? How can we help?
- Organize a school tree planting in the garden.
- Do some tree yoga poses.
- Go on a tour of the different trees growing in the garden or around the school.
Thank you One Cool Earth!
The lessons and resources for this topic have been adapted from the Earth Genius curriculum developed by One Cool Earth, a California 501(c)3 non-profit dedicated to bringing garden education to students.