Teaching Sequence

Work through this resource material in the following sequence:

10 minutes – Part A: The context - Briefly introduce students to the IPCC's Sixth Report on climate change science, and the hope lens we will use for approaching potential solutions to the challenges the report presents.
10 minutes – Part B: The challenge - Explicitly teach students about the atomic composition of CO2 and how photosynthesis changes its molecular nature as a way of approaching carbon dioxide recovery solutions.
30 minutes – Part C: The solution - Students design a solution that recovers CO2 from Earth's atmosphere.
10 minutes – Part D: Reflection - Students share and explain their designs and discuss further challenges they encountered during the design process.

Part A: The context

Step 1.

Explain to your class that the Intergovernmental Panel on Climate Change (IPCC) is the United Nations body for assessing the science related to climate change. It was created to:

provide policymakers (governments) with regular scientific updates about climate change;
highlight the impact climate change will have on the planet in the future; and,
offer some ideas about how to tackle the challenges of climate change's potential effects on the planet.

In 2021-22, the IPCC released Part 1 of the Sixth Assessment Report. This is the most up-to-date physical understanding of the climate system and climate change.

Step 2.

The report makes a number of important points:

It is unequivocal that human influence has warmed the atmosphere, ocean and land (A1). You might like to take a moment to discuss with students the meaning of the word unequivocal.
Global surface temperature will continue to increase until at least mid-century under all emissions scenarios considered. Global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in CO2 and other greenhouse gas emissions occur in the coming decades (B1). The report describes five possible climate futures, where #1 is not great and #5 is extremely bad. If we want to keep global warming at less than two degrees, which the IPCC says is the best-case scenario, we need to reduce our C02 and greenhouse gas emissions significantly, and start right away.

Step 3.

Explain that 'net zero' or 'carbon neutral' are terms that refer to achieving an overall balance between greenhouse gas emissions produced and greenhouse gas emissions taken out of the atmosphere. Getting to net-zero means we can still produce some emissions, so long as we're doing something else to reduce the greenhouse gases already in the atmosphere at the same time, kind of like balancing a set of scales (more info).

Step 4.

Give students some time to respond to this information. Enable them to share their feelings and discuss their thoughts on the matter, so that they feel validated and reassured about approaching this content.

Acknowledge how hard a challenge this report sets. While this real-world issue is essential for students to understand, there is no doubt it can make them feel sad or anxious about the future becoming darker and scarier by the day.

So, reassure students that we can have a hopeful and optimistic outlook on this report, rather than one of doom and gloom. Explain that optimism involves looking objectively at a situation and making a conscious decision to focus on the good (more info), and that hope is the belief that you can make an impact (more info). Explain to students that you are going to look ahead, identify what needs to be improved, and then work on the skills and confidence so that they can go out and do it.

If you're interested in learning more about how to approach challenging topics in your classroom through a Hope and Optimism lens, consider our PD course.

Part B: The challenge

Step 1.

It's important to reiterate to students that the most important and proactive step in addressing our current climate crisis is to reduce our carbon emissions to net-zero, as with every additional increment of global warming, changes in extremes grow exponentially. So prevention of further damage is an important consideration. Many of the other lessons in our unit on Climate Change Solutions look at how we can reduce our current emissions.

However, the IPCC report states that even if in the best-case emissions scenario they considered - that is, if we dramatically reduce our emissions and work on nursing the planet back to health - global surface temperature will still continue to increase until at least mid-century, stating that "m any changes due to past and future greenhouse gas emissions are irreversible for centuries to millennia, especially changes in the ocean, ice sheets and global sea level." It is hard to undo a lot of the damage we have already done.

So, thinking creatively, how could we remove a lot of the carbon emissions we have already created, rather than just aiming to reduce further emissions in the future?

Before we start thinking about that, let's look at how carbon works on a molecular level.

Step 2.

Explain to students that humans are producers of CO2. This is called cellular respiration. We breathe in oxygen, and use energy from that to break down glucose (sugar, from our food) into energy which we can use to go about our day. Carbon dioxide is produced as a waste byproduct, which we breathe out. This process also produces some water.ending on your students, you can explore this molecular process in detail.

Step 3.

Watch:

Overview of cellular respiration | Cellular respiration | Biology | Khan Academy (https://www.youtube.com/watch?v=9zoS5WGsmpc)

Step 4.

Interestingly, plants work in kind of the opposite way. They take in carbon dioxide from the atmosphere and water from their roots, and use energy from the sun to turn the water and CO2 into glucose which they can use to grow. This process also produces oxygen, which, since flowers and trees don't have lungs, they release as a waste byproduct back into the atmosphere.

This is why natural climate solutions such as planting trees and protecting old-growth forests from logging is such an important part of working towards net-zero, as you can see in this lesson about protecting nature.

Step 5.

It's important to understand this because, as Antoine Lavoisier discovered, mass (or matter) can neither be created or destroyed, although it can change forms. We have a lot of carbon dioxide which is not helping the atmosphere, but within that CO2 are some actually very useful oxygen molecules.

The CO2 breathed by astronauts aboard the International Space Station is captured by a sponge-like mineral called a zeolite, which has tiny pores to lock in a CO2 molecule. The zeolites empty their CO2 when exposed to the vacuum of space.

Scientists are currently trying to apply this zeolite technology, as well as our understanding of photosynthesis and chemistry, to scrub the CO2 from Earth's atmosphere.

Part C: The solution

Step 1.

Independently, students will come up with a way to remove carbon dioxide from the atmosphere.

The IPCC calls this approach Carbon Dioxide Removal (CDR): "Anthropogenic activities removing CO2 from the atmosphere and durably storing it in geological, terrestrial, or ocean reservoirs, or in products." Anthropogenic means "done by humans", so not relying on nature but being active in this effort and creating solutions.

CDR can help us work towards net-zero by compensating for some of the emissions we continue to produce. However, a big CDR effort could even have a net-negative effect on carbon emissions.

Provisions for Learning Support and Learning Extension: Depending on your individual students, you might like to have them independently conduct research (the below resources are also available as part of the Student Worksheet), or work through the resources together as a class.

Alternatively, you might want to remove many of the more 'technical' considerations to encourage students' creativity and imagination. After all, we don't come up with new solutions to challenges by following what we've already been doing for so long.

What could a CDR machine look like if unburdened by the constraints of current technologies? Perhaps you could make some sort of massive vacuum that just pumps the CO2 emissions out into space. You'd still need some way of filtering the CO2, however.

Step 2.

One potential solution would be to take a process that nature has already perfected, make it even more efficient, and produce it on a mass scale.

Watch:

Artificial Trees That Absorb CO2 - Hot Planet Preview - BBC One (https://www.youtube.com/watch?v=JUSSTYJslXQ)

There still remains the challenge of where to store the captured CO2 after washing the plastic. Currently scientists are looking at storing the CO2 in the ground.

Step 3.

It is possible to split a CO2 molecule into more useful elements - the only catch is, this process requires energy, and if we use fossil fuels to generate that energy, we will simply end up with more carbon emissions than we started with.

However, so long as this energy is derived from green sources, such as wind or solar energy, then CO2 can be split into oxygen, carbon monoxide and hydrogen, of which the latter two are basic chemical building blocks that can be used to produce synthetic fuels (see more in our lesson on electrifying transport).

Step 4.

Give students some time to independently explore solutions that already exist in this space. After some brainstorming, have them have a look at what is available on the Student Worksheet

Step 5.

Give each student a copy of the Student Worksheet to guide their design process.

Students will have to explain:

How their solution works: How is your solution absorbing and filtering carbon dioxide from the atmosphere?
Fuel: What is powering the solution? Remember, if we use fossil fuels to generate the energy to recover carbon dioxide, we are simply producing more carbon dioxide to replace it.
Storage: What is happening to the CO2 after it is recovered from the atmosphere? Explain how this solution will not cause more environmental issues in the future.

Provisions for Learning Differentiation: Designing a solution to recovering carbon emissions might strike students as counter-intuitive. After all, we already have trees, and are deforesting the earth at an alarming rate. And shouldn't we first be focusing our energy on ways to end our reliance on fossil fuels?

Allow students the space to explore natural climate solutions or other campaigns which address future carbon emissions.

Reflection

Encourage students to share their designs with the class, or with a partner.

Ask students to reflect on the following questions:

What potential challenges do you see with implementing this solution?
What part of the solution do you think still requires some thought?

Encourage students to ask questions and offer feedback to their peers.

Where to next?

Many scientists believe natural climate solutions and natural carbon sinks such as algae, seaweed, and old-growth forests, can go a long way to counteracting our carbon emissions, but these all come with their own challenges, which you can explore in these lessons.

This lesson raises a great question: who is paying to fund all this research into carbon capture technologies? Much of it is funded by fossil fuel companies, which doesn't sit well with some scientists. Is this a government obligation? Or something that should be funded by private enterprise? Discuss these challenges questions in more detail in our lesson What's the cost?

If the IPCC report has really inspired your students, check out our unit on finding other solutions to our emissions challenges.

Teacher Reflection

Take this opportunity to reflect on your own teaching:

What did you learn about your teaching practice today?
What worked well?
What didn't work so well?
What would you share?
Where to next?
How are you going to get there?

IPCC - C02 Scrubbers

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