Student Exploration Carbon Cycle Lecture Notes

Student Exploration: Carbon Cycle Vocabulary: atmosphere, biomass, biosphere, carbon reservoir, carbon sink, fossil fuel, geosphere, greenhouse gas, hydrosphere, lithosphere, photosynthesis Prior Knowledge Questions (Do these BEFORE using the Gizmo.) In the process of photosynthesis, plants take in carbon dioxide (CO2) from the atmosphere and water (H2O) from the soil. Using the energy of sunlight, plants build molecules of glucose (C6H12O6) and oxygen (O2). 1. How do plants on Earth affect the amount of carbon in Earth’s atmosphere? Plants take CO2 and make it into oxygen 2. Animals eat plants and produce carbon dioxide and water. How do animals affect the amount of carbon in Earth’s atmosphere? They eat plants to harness the carbon. Gizmo Warm-up The Carbon Cycle Gizmo allows you to follow the many paths an atom of carbon can take through Earth’s systems. To begin, notice the black carbon atom in the Atmospheric CO2 area, highlighted in yellow. The glowing blue areas represent possible locations the carbon atom could go next. 1. From Earth’s atmosphere, where can the carbon atom go next? The atom can go to the Ocean, land plants, and exposed rock. 2. Click on Land plants and read the description. How did the carbon atom get from the atmosphere to a plant? Plants use the sun for photosynthesis 3. Select Land animals. How did the carbon atom get from land plants into the animal? Land animals consume plants for energy 4. Select Atmospheric CO2. How did the carbon atom get from land animals back to the atmosphere? They release carbon into the atmosphere through cellular respiration Activity A: Get the Gizmo ready: Carbon pathways  Click Reset. Introduction: Earth can be divided into four systems. The atmosphere is the air above Earth’s surface. The hydrosphere is composed of all of Earth’s water. The geosphere is the rocky, non-living part of Earth. The biosphere consists of all living things, including people. Some scientists use the term “anthroposphere” to describe everything made or modified by humans. Question: How does carbon move between the atmosphere, hydrosphere, biosphere, and geosphere? 1. Explore: Use the Gizmo to create a path for carbon that begins and ends in the atmosphere. Fill in the steps in the path below. Then, label each location with the system it represents. Finally, summarize very briefly how the carbon atom got to that location. Carbon path System Atmospheric CO2 Atmosphere Plants Exposed How it got there Exposed Rock Atmospheric CO2 comes from volcanoes, burning fossil fuels, and other sources. Streams and rivers Oceanic CO2 Marine Animals Shells/Coral Calcium Carbonate structures Limestone Limestone Magma Volcano Volcanic eruptions Atmospheric CO2 2. Create: Click Reset. Use the Gizmo to create a path in which the carbon atom goes from the atmosphere to the hydrosphere, biosphere and geosphere. Describe each transition briefly. Atmosphere Atmospheric CO2 Volcanoes, burning fossil fuels, and other sources. Hydrosphere Biosphere Geosphere Activity A (continued from previous page) 3. Explore: Use the Gizmo to create three more carbon paths, each starting and ending in the atmosphere. Label each location with A for atmosphere, B for biosphere, G for geosphere, or H for hydrosphere. (You can also use P for anthroposphere if you like, or just include it in the biosphere.) Path 1: Atmosphere  Oceanic CO2  Atmosphere Path 2: Atmosphere  Land Plants  Coal  Power Plant  Atmosphere Path 3: Atmosphere  Land Plants Land Animals  Atmosphere 4. Explain: Based on the Gizmo, explain how the following transitions might take place: A. Describe at least two ways that carbon can get from a land plant to the atmosphere. Carbon can be eaten and those animals release carbon when they decompose. Carbon can be released when plants are cut down. B. Describe at least two ways that carbon can get from the atmosphere to the hydrosphere. Dissolved cold waters can go into oceanic CO2. As well as exposed rock. C. Can you find two ways that carbon can get from the ocean to the lithosphere? (The lithosphere is the rigid layer of the Earth, including the crust and part of the mantle.) Limestone and shells. D. Describe at least two ways that carbon can get from seashells to the atmosphere. Limestone and shells go to lithosphere to volcanos and volcanic eruptions. As well as cement plants. Activity B: Get the Gizmo ready: Human activities  Click Reset. Introduction: Fossil fuels, such as coal, oil, and natural gas, formed over millions of years from the remains of ancient plants and animals. The burning of fossil fuels, as well as other human activities, increases the amount of carbon dioxide in the atmosphere. Question: How does human activity affect the carbon cycle? 1. Describe: Using the Gizmo, determine how coal and petroleum (oil) are formed. Describe the steps required to form each fuel from atmospheric CO2. Coal: Goes from atmosphere to plants in photosynthesis. When the plant is compressed it forms coal Petroleum: Goes from the atmosphere to plants in photosynthesis. When the plant dies, it goes from soil to sediment to petroleum. 2. Explore: Natural gas is a mixture of methane (CH4), ethane (C2H6), and other gases. Find two ways that natural gas forms. List the steps of the two carbon pathways below: Path 1: Path 2: How is the formation of natural gas related to the formation of coal and petroleum? The formation of natural gas is related to the formation of coal and petroleum because they are both made from the same thing and one of our ways of fuel. They both produce carbon dioxide when being used for fuel. 3. Describe: Fossil fuels are used in many ways. Using the Gizmo, describe the main use for each fuel. Coal: Electricity generation Petroleum: Fuel Natural gas: Energy In each case, what is the end product of burning the fossil fuel, and where does it go? The atmosphere. CO2 ends up in the atmosphere. 4. Explore: Another major contribution to atmospheric carbon dioxide is the cement industry. Using the Gizmo, find a carbon atom path from the atmosphere to the cement plant. (Hint: One of the ingredients in cement is limestone.) Path: Atmosphere - Ocean CO2 - Shells - Limestone - Cement Plant How is carbon dioxide produced in a cement plant? The materials release CO2 as they are broken down 5. Analyze: Click Reset, then navigate to the Land animals. Select Atmospheric CH4. A. How do land animals create methane? Bacteria in them break down materials in their stomach and release methane. B. Humans raise large numbers of cattle for food. How will these herds of cows affect Earth’s atmosphere? They will put more methane gas in the atmosphere. 6. Analyze: In many tropical rainforests, people clear land by cutting down trees and burning them. After a few years, the soil runs out of nutrients and cannot be farmed any longer. How does this practice of “slash and burn agriculture” affect Earth’s atmosphere? This will leave us without any trees to convert the CO2 in our atmosphere to oxygen causing even more global warming and climate change. 7. Draw conclusions: In general, how do many human activities influence the carbon cycle? The over use of carbon emissions in cars and factories will run the Earth out of natural energy and further the effects of global warming leaving us with no energy on a unhealthy planet.