carbon cycle stories - biochar ebooks cycle stories.pdf · 2013-03-03 ·...
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Carbon Cycle Stories and Biochar A free activity from Biochar-‐eBooks.com
Includes: • What Is Biochar?
• Explanation of the Carbon Cycle
• Draw a Carbon Cycle Diagram
• Dinosaur Breath Story and Activity
• Make a Carbon Dioxide Model
• Tell Your Own Carbon Cycle Story
• Carbon Cycle Story Collage
• How Does Biochar Fit Into the Carbon Cycle?
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Carbon Cycle Stories and Biochar What is Biochar? Biochar is charcoal that is made from biomass (like wood or straw) by applying heat in the absence of oxygen. Heat bakes the biomass, releasing flammable gasses and leaving behind a solid carbon structure -‐ charcoal. Most such charcoal is good for soil. When we add it to soil it becomes biochar. Biochar is like permanent compost -‐ a source of soil carbon that supports soil life, but unlike compost, it does not break down very fast. In the Amazon, people added biochar to soils over thousands of years to help grow food crops. Some of the biochar is still there, thousands of years later! Because plants pull carbon dioxide out of the air when they grow, when you convert part of that carbon to biochar and put it in the soil, you are reducing the amount of carbon dioxide in the atmosphere. But be careful, your biomass must be sustainably grown and harvested and your biochar production process must be clean, or you might make more carbon dioxide than you bury as biochar. If we do it right, BIOCHAR CAN HELP STOP CLIMATE CHANGE! What is the Carbon cycle? Why is it important? How does it work? We all need energy to survive and do things. Where does this energy come from? Our main source of energy is the Sun. But did you know, that only plants, algae and a few types of bacteria can use sunlight directly as a source of energy? Other than these organisms, no other organisms can convert the energy obtained from the Sun into the nutrients required for their survival. So, all of us have to depend on plants for our nutrition and survival, and plants, in turn, use carbon dioxide along with sunlight, to make their own food by the process of photosynthesis. The food builds their tissues, and a lot of the carbon dioxide they use ends up as part of plant tissues. We and other animals eat these tissues and then the carbon becomes part of us too. By weight, around 18% of the human body is carbon. All beings on Planet Earth are carbon-‐based life forms.
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Explanation of the Carbon Cycle The carbon cycle is the exchange of carbon between the various organic and inorganic elements in the atmosphere, the biosphere, the oceans and the lithosphere (rocks). The processes that release carbon in the atmosphere are called the sources, while those that absorb carbon from the atmosphere are called the sinks. Here is how the carbon cycle works:
1. Carbon dioxide from the atmosphere is used by plants in the process of photosynthesis. This is the process that breaks down carbon dioxide into compounds that can be used as nutrition by the plants. In this process, plants release oxygen as a byproduct.
2. Animals and humans consume these plants, and thus the carbon is transferred from the plants to animals and humans.
3. From animals and humans, the carbon is sent back to the atmosphere when we breathe out -‐ through the process of respiration.
4. Other than respiration, when plants, animals or humans die, their remains decay and decompose, and carbon is transferred to the soil when this happens. When the remains are deeply buried for thousands of years, they become fossil fuels, and these are huge sinks of carbon.
5. Burning of wood or fossil fuels are both processes that transfer carbon back to the atmosphere, but with different effects. Fossil fuels, by definition, are made of old carbon that was fixed by plants millions of years ago. When you burn old carbon, you increase the total amount of carbon in the atmosphere. Burning trees is burning new carbon, and most of that would have ended up in the atmosphere anyway, through respiration.
6. Oceans and other huge water bodies, which have cool water on the surface, also absorb some carbon from the atmosphere. But oceans exhibit dual behavior. When the surface water is cooler (as may happen in cold regions, near the poles) carbon is absorbed into the water, whereas when the surface water is warm (near tropical regions), carbon is released into the atmosphere, from where the plants will again absorb it for photosynthesis, and the cycle repeats.
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Here is a diagram that shows the basic parts of the Carbon Cycle:
Draw your own Carbon Cycle Diagram that shows the plants, animals and human sources of carbon dioxide that you are familiar with:
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Carbon Cycle Stories – Dinosaur Breath Let’s follow the journey of a single carbon atom starting 100 million years ago, when a dinosaur ate a fern that contained our carbon atom.
1. The carbon atom was part of a carbohydrate molecule that was formed when the fern used carbon dioxide from the atmosphere to make its food using photosynthesis. The dinosaur pulled up the fern and chewed it.
2. The fern went through the dinosaur’s digestive system where the carbohydrate
molecule was used for energy. But some carbon was left over and through its respiration process, the dinosaur breathed out the carbon atom.
3. The carbon atom floated up in the atmosphere and ended up over the cold
ocean.
4. A wind blew it onto the surface of the water and it was absorbed into the ocean water as dissolved carbon dioxide.
5. A tiny plankton organism floating near the surface was building its calcium
carbonate shell. It used our carbon atom in its shell.
6. Soon, it died and its shell slowly drifted down to the bottom of the deep ocean.
7. It stayed there for 60 million years in the ocean sediments, but the sea floor was slowly rising up as the Earth shifted, and eventually the seafloor was raised up into a cliff beside the ocean.
8. The cliff was a chalk cliff and chalk is just a huge collection of old seashells from
plankton and other organisms.
9. Our carbon atom stayed there for another 40 million years until a mining company came along and mined some chalk to make your school supplies.
10. Then we dropped the chalk in vinegar and the acid dissolved the calcium
carbonate and released carbon dioxide into the atmosphere – it is the same old dinosaur breath.
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Dinosaur Breath Activity – Releasing Carbon Dioxide from Chalk Supplies needed: a few jars, white vinegar, chalk, seashells
• In this experiment, we take pieces of chalk and seashells and drop them into a jar of vinegar.
• Bubbles form, releasing CO2 as the chalk and shells dissolve.
• We discuss how the carbon in the CO2 could have passed through the body of a
dinosaur in ancient carbon cycling.
• We also drop other materials like wood or plastic in the vinegar and observe that they do not emit bubbles of CO2.
• This leads us to discuss how carbon in wood gets released to the atmosphere –
through decomposition or burning. Make a Carbon Dioxide Model You can make a model of a carbon dioxide molecule using toothpicks and gumdrops. Use a different color gumdrop for each element in the molecule – one color for carbon and one color for oxygen. You can make other molecules containing carbon that are also part of the carbon cycle, like methane or water. Sugar is part of the carbon cycle (we eat it) so you can make a model of a sugar molecule out of sugar!
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Tell Your Own Carbon Cycle Story Every living thing contains carbon, and every living thing has a story: The story of a leaf…
The story of a feather…
The story of a seashell…
The story of a bug…
The story of the salmon…
The story of my breakfast…
The story of my car…
The story of my family…
The story of …
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To help tell your story, make a Carbon Story Collage, like this one:
Lauren traces her carbon atom through its carbon cycle story.
The carbon atom (shown in detail with all of its electrons and protons) travels from an ancient fern to a dinosaur’s mouth to a seashell. After 100 million years it ends up in a little girl’s hand in a piece of chalk. Who knows where it will go next? Maybe it will go back in the ground for thousands of years in a piece of biochar.
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How does Biochar fit into the Carbon Cycle story? This diagram shows how the Biochar Cycle can change the Carbon Cycle:
You can turn plants into biochar and then bury the biochar in the ground where it helps new plants grow bigger and better. Biochar that is buried in the ground keeps carbon dioxide out of the atmosphere. Also, you can capture energy from the biochar-‐making process and do useful things with it, like cook your dinner.
This WhirlyGirl stove is burning gas from wood pellets. Biochar will be leftover after the food is done cooking. These students have used biochar in the soil mix – the tall plant is the one growing in the biochar mix.
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Look for all of these ebooks in the Getting Started With Biochar Series:
• Make Your Own Biochar Stove: Quick & Easy
• Exploring Biochar: Classroom Activities and Lessons
• Cheap & Easy Backyard Biochar Production
• Using Biochar in Soil and Sanitation
More information at www.biochar-‐ebooks.com
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