ENVR 1401 , Exploration- Carbon Cycle Questions And Answers

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Name: Date: 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? The plants take in the carbon that is in the air to start the process of photosynthesis which helps us because as they take in the carob it reduces how much is in the air which is good for us. 2. Animals eat plants and produce carbon dioxide and water. How do animals affect the amount of carbon in Earth’s atmosphere? As there are more animals the carbon will increase. 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? To the land plants. 2. Click on Land plants and read the description. How did the carbon atom get from the atmosphere to a plant? The carbon atom gets there by the process of photosynthesis. 3. Select Land animals. How did the carbon atom get from land plants into the animal? The animals eat the plants or the other animals which have ate the plants for energy. Only a small amount of plant carbon is consumed. 4. Select Atmospheric CO2. How did the carbon atom get from land animals back to the atmosphere? The animal release the carbon back into the air by the process of cellular respiration. 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 How it got there Atmospheric CO2. Atmosphere Atmospheric CO2 comes from volcanoes, burning fossil fuels, and other sources. Land plants Biosphere Atmospheric co2 comes from volcanoes, burning fossils fuels, and other sources. Land plants Biosphere Plants go through photosynthesis. Land animals Biosphere Animals eat plants to gain energy. Soil Geosphere Animals die and remains decay into the soil. Sediments Geosphere Soil washed into steams and build up under water masses. Lithosphere Geosphere Sediments get compressed into sedimentary rocks that are rich in carbon Volcano Geosphere Rocks melt underground and release CO2 which is mixed into magma. Atmospheri c CO2 Atmosphere Volcano erupts putting CO2 back into the Atmosphere. 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 Hydrosphere Biosphere Geosphere Atmospheric CO2 Oceanic CO2 Marine Plants. algae Sediments Volcanoes, burning Cold temperatures Plants and Algae go Plants and Algae fossil fuels, and from the ocean through sink to the bottom of other sources. dissolves CO2 and photosynthesis. the ocean building stores it into deep up large amounts of waters. carbon. (Activity A continued on next page) 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: Path 2: Path 3: 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. B. Describe at least two ways that carbon can get from the atmosphere to the hydrosphere. 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.) D. Describe at least two ways that carbon can get from seashells to the atmosphere. 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: Atmosphere CO2, land plants, coral. Petroleum: Atmosphere CO2, ocean CO2, marine plants, marine animals, sediments, 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: Atmospheric CO2 land and plants Soil Atmospheric CH4 Path 2: CO2 land plants Land animals Atmospheric CH4 How is the formation of natural gas related to the formation of coal and petroleum? Both formed? Both are formed from organic remains and both from lots of pressure in a sedimentary sequence 3. Describe: Fossil fuels are used in many ways. Using the Gizmo, describe the main use for each fuel. Coal: Makes up about 85% of fossil fuel carbon. Used to power plants and generate electricity. Petroleum: Known as a crude oil is refined into gasoline to run cars and used to make plastic. Natural gas: CH4 is broken down to make CO2 which goes through photosynthesis In each case, what is the end product of burning the fossil fuel, and where does it go? Release carbon dioxide which is a greenhouse gas goes up into the atmosphere. (Activity B continued on next page) Activity B (continued from previous page) 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: Atmospheric CO2 Oceanic CO2 Shells/ coral Limestone Cement How is carbon dioxide produced in a cement plant? Limestone is heated, producing calcium oxide and carbon dioxide? CaO used to make cement and CO2 is released to the atmosphere. 5. Analyze: Click Reset, then navigate to the Land animals. Select Atmospheric CH4. A. How do land animals create methane? Bacteria break down undigested materials produce methane gas. As the animal’s fart and poo and this is the same for humans. B. Humans raise large numbers of cattle for food. How will these herds of cows affect Earth’s atmosphere? It will create a lot of CH4 which will create more CO2 and cause global warming to go up. 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? It increases CO2 because burning wood produces Carbon dioxide. 7. Draw conclusions: In general, how do many human activities influence the carbon cycle? It speeds it up. Introduction: Humans have been burning fossil fuels rapidly for the past 250 years. As a result, the amount of atmospheric CO2 has increased by about 40% since the year 1800. By measuring how much carbon moves into and out of the atmosphere, scientists can predict the change in the amount of atmospheric carbon dioxide every year. Question: How can we model changes in atmospheric carbon over time? 1. Observe: The MODEL tab shows a simplified model of the carbon cycle. The ovals represent carbon reservoirs, where carbon is stored. The unit “GtC” stands for gigatonnes of carbon, where one GtC is equal to one trillion kilograms of carbon. The arrows represent how much carbon moves from one reservoir to another each year, in gigatonnes per year. A. Look at the arrows pointing toward atmospheric CO2. What are the two major sources of atmospheric carbon? B. A carbon sink is a location that stores carbon for a long period of time. Which two carbon sinks remove carbon from the atmosphere? C. Without changing the Gizmo, list the carbon reservoirs from largest to smallest. Note: The largest carbon reservoir is actually Earth’s lithosphere, which contains about 80,000 GtC. However, there is not much exchange between the lithosphere and the other reservoirs on short time scales. 2. Experiment: If necessary, click Return to original settings. These settings approximate present-day conditions, but should not be taken as exact values. A. What is the total amount of carbon removed from the atmosphere each year by the ocean and land plants? B. What is the total amount of carbon added to the atmosphere from soil and the burning of fossil fuels? C. How much will atmospheric carbon change in one year? In 10 years? In 100 years? (Activity C continued on next page) Activity C (continued from previous page) 3. Calculate: Carbon dioxide is a greenhouse gas that helps to trap heat in Earth’s atmosphere. We need some CO2 in the atmosphere to maintain a warm planet, but excess carbon can cause considerable warming of the planet. A. What fossil fuel usage will result in no change in atmospheric CO2 each year? B. What percentage decrease in fossil fuel usage is required to achieve this goal? 4. Experiment: Using the Gizmo model, explore the following questions: A. How does increasing plant biomass (amount of plants) affect atmospheric CO2? B. How does increasing oceanic CO2 intake affect atmospheric CO2 and oceanic CO2? As carbon dioxide is absorbed by the ocean, the ocean becomes slightly more acidic. This could make it harder for many organisms to build their shells and skeletons. The consequences of ocean acidification are not yet fully understood. 5. Infer: Click Reset and Return to original settings. Suppose we completely stopped burning fossil fuels immediately. How many years would it take to return to atmospheric CO2 levels from the year 1800, about 600 GtC? Use the Gizmo to find the answer. 6. Think about it: Since hard-shelled organisms evolved about 550 million years ago, billions of tons of limestone rock have been produced from their shells. Limestone is made of calcium carbonate, with the formula CaCO3. Based on this, how do you think the amount of atmospheric CO2 has changed in the last 550 million years, and how has this affected Earth’s climate? Explain your answer. [Show More]

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