ESS Module 8- 8:01 Carbon Cycle
Describe each of the main carbon reservoirs on Earth.
(The atmosphere contains carbon in the form of carbon dioxide (CO2). The amount of carbon dioxide in the atmosphere (which is also used by plants for photosynthesis and released from living things in respiration) changes based on how the forms of inorganic carbon cycle between the spheres of Earth.) (The terrestrial surface of Earth is made primarily of plants, soil, sediment, and rock. All living things are part of the biosphere and the soil and rocks are part of the geosphere. Carbon is stored in the form of carbonates in certain rocks, minerals, and soils. Organic compounds are found in living matter.) (The ocean is part of the hydrosphere and is the largest reservoir of carbon. It contains carbon, mainly in the form of calcium carbonate in coral and seashells, as well as dissolved carbon dioxide in the water.) (Fossil fuels contain carbon from dead plants and animals that lived long ago. The carbon is stored in the form of coal, oil, and natural gas, and is part of the geosphere.)
Carbon sinks
A process that absorbs carbon
carbon sources
A process that releases carbon
Which surface features on Earth contain organic carbon?
Biological compounds (living matter) like soil, moss, grass, trees, microbes, coral, insects, and animals are composed primarily of organic carbon.
List examples of carbon sinks and carbon reservoirs.
Carbon Sink- Oceans (ocean acidification) photosynthesis Fossil fuel formation Shell formation Carbon Reservoir- fossil fuels The terrestrial surface The ocean atmosphere
Identify the cause and effect of human activity on the carbon cycle.
Cause- Thawing permafrost Effect: Previously trapped organic carbon decays and is released into the atmosphere. Cause- Cutting down forests (deforestation) Effect: There is a decrease in the rate that plants remove carbon dioxide from the atmosphere. Deforestation is the action of removing a large amount of trees from an area. We rely on plants to cycle carbon dioxide from the atmosphere to create oxygen through the process of photosynthesis. If there are less plants to remove the carbon dioxide, then this causes an increase in atmospheric carbon dioxide and a decrease in oxygen levels. Cause- Burning fossil fuels Effect: Land plants and oceans are absorbing more carbon dioxide. The burning of fossil fuels increases atmospheric carbon dioxide because the carbon that was trapped in coal, oil, and natural gas is released into the atmosphere. Cause- Ocean acidification Effect: Shells of organisms like plankton or snails will be weaker and thinner due to the CO2 and carbonate ions combining. Around 30% of the carbon dioxide emitted by human activities has been absorbed by the oceans. When there is more carbon dioxide in the oceans, the oceans become acidic. As more carbon dioxide enters the ocean, it combines with carbonate ions, making it so there are less carbonate ions available for shell-building organisms, like plankton or coral, to use. This results in thinner and more fragile shells and disrupts the life cycle of many ocean creatures.
How do greenhouse gases apply to the carbon cycle?
Gases that absorb thermal energy are known as greenhouse gases, such as water vapor, carbon dioxide, and methane. When solar energy reaches Earth, several things happen to it: Earth absorbs it, it is cycled throughout Earth's atmosphere, or it flows through the atmosphere back into space. As the amount of carbon dioxide in the atmosphere increases due to human activities, the more radiation Earth's atmosphere holds. This is what drives the potential imbalances within the carbon cycle.
How is inorganic carbon created? How is the compound bonded together?
It is geologically created and it contains no carbon-hydrogen bonds.
Which surface features on Earth contain inorganic carbon?
Non-biological compounds (non-living matter) like rain, ocean water, rivers, sediments, rock, volcanoes, and gases are primarily inorganic compounds. Inorganic compounds are the most abundant form of carbon on Earth.
What is a carbon reservoir?
On Earth, carbon is stored in, and moves through, four main reservoirs. A carbon reservoir is a place where carbon is stored within the carbon cycle. Oceans, fossil fuels, the terrestrial surface, and the atmosphere are the four main carbon reservoirs on Earth.
Sort the items below according to whether they describe organic or inorganic carbon.
Organic Carbon- Biologically created Contains at least one carbon-hydrogen bond Found in plants and animals Inorganic- Geologically created Most abundant form of carbon Contains no hydrogen-carbon bonds Found in volcanoes
Describe how carbon is cycled through the Earth's spheres in the simulation.
Respiration- Biosphere: Respiration is the process that plants and animals go through to break down food molecules and convert them to energy. Atmosphere: During the carbon cycle, animals release carbon dioxide back into the atmosphere through cellular respiration, and plants remove carbon dioxide through photosynthesis. Volcanic Eruption- Biosphere: In the ground, the carbon contributes to photosynthesis in plants. Atmosphere: In the atmosphere, carbon helps maintain Earth's temperature. Geosphere: Volcanic ash is composed of silicate and carbon dioxide. When eruptions occur, ash covers the land. Hydrosphere: As volcanic ash is broken down, carbon dioxide is absorbed back into the ground when it rains, as well as back into the atmosphere. Runoff- Biosphere: The carbon dissolves and is transported to the ocean where it is used by marine plant life when undergoing photosynthesis. Geosphere: Some forms of carbon are trapped in rocks. As weathering occurs, carbon is gradually released into the atmosphere and is also carried to rivers and streams by precipitation runoff. Weathering- Biosphere: In the ocean and rivers, carbon dioxide contributes to photosynthesis for plant life and balances the water's pH levels. Atmosphere: When carbon is no longer trapped in rocks, it is released into the atmosphere where it helps maintain Earth's temperature. Geosphere: As rock is worn down by weathering, carbon is exposed. Hydrosphere: Additional carbon becomes available to travel to rivers and the ocean by rain runoff. Photosynthesis- Biosphere: The energy is used by plants to grow and complete their biological processes. In turn, plants become energy for other organisms. This is one of the most essential processes in the carbon cycle because it propels the movement of carbon from the atmosphere to plants and animals. Atmosphere: During photosynthesis, plants absorb sunlight and carbon dioxide from the atmosphere to create energy, such as glucose and other sugars. Oil, Natural Gas, and Coal- Biosphere: Fossil fuels are made from decomposing plants and animals. Atmosphere: When these fossil fuels are burned to power factories, power plants, cars and trucks, carbon moves into the atmosphere as carbon dioxide gas. Geosphere: These fuels are found in the geosphere and contain carbon and hydrogen, which can be burned for energy. Coal, oil, and natural gas are examples of fossil fuels. Mining- Geosphere: Underground mining is used to extract ore that is processed into coal. When the coal beds are disturbed, carbon dioxide is released in the atmosphere where it becomes available to move through the carbon cycle. Animals- Biosphere: When animals eat food, the carbon that is stored in the food source is ingested into their bodies and used as nutrients. Atmosphere: When animals exhale, some of that carbon recombines with oxygen and is released back into the atmosphere as a waste product called carbon dioxide. Industry and City- Atmosphere: As a byproduct, carbon dioxide is emitted from the burning of fossil fuels and is released into the atmosphere. When it is in the atmosphere, it becomes available to continue moving through the carbon cycle. Geosphere: Urban activities such as running factories, car emissions, maintaining landfills, and mining for ore are all important for industry and city life. Carbon Dioxide- Atmosphere: A greenhouse gas called carbon dioxide (CO2) is the primary gas emitted through human activities and is a main factor in the carbon cycle. Limestone- Geosphere: Weathering of limestone deposits by rain returns carbon to rivers, streams, and other water reservoirs in the hydrosphere where it is used by photosynthetic organisms. It also allows carbon to return to the atmosphere as carbon dioxide. Methane- Biosphere: A greenhouse gas called methane (CH4) enters the atmosphere as a product of landfills, rice farming, and cattle farming. Atmosphere: The carbon in methane then recombines with a charged oxygen atom bonded to a hydrogen atom (OH) to form carbon dioxide (CO2). Agriculture- Geosphere: Agricultural practices and land use changes the amount of carbon stored in plant matter and soil, and impacts how carbon is cycled between the land and the atmosphere. Swamps- Biosphere: Carbon is held in the living vegetation as well as in litter, peats, organic soils, and sediments that have built up over thousands of years. Hydrosphere: Swamps are carbon sinks that pull carbon from the atmosphere through plant photosynthesis and by acting as sediment traps for runoff. Decomposition/Soil Formation- Biosphere: Decomposers are organisms and microbes in the soil that break down dead and decaying matter. Geosphere: During the decomposition process, decomposers undergo respiration and create carbon dioxide, which is released back into the soil. Plants- Atmosphere: Plants absorb carbon dioxide from the atmosphere during photosynthesis to create energy. At night, they release carbon dioxide into the atmosphere while undergoing cellular respiration. Biosphere: Plants are the organism that helps to propel the carbon cycle forward by engaging in photosynthesis and respiration. Respiration (Ocean)- Biosphere: This is the process that plants and animals go through to break down food molecules and convert them to energy. Atmosphere: As respiration cycles carbon in and out of the ocean water, it becomes available to be released back into the atmosphere, or to be used by other marine organisms. Hydrosphere: In the ocean, phytoplankton release carbon dioxide into the water through cellular respiration. They remove dissolved carbon dioxide from the ocean water through photosynthesis. Food Web- Biosphere: Food webs and the carbon cycle are very closely related because every living organism is made up of carbon. A food web connects producers (photosynthetic organisms), consumers, and decomposers. Geosphere: Organisms in the biosphere move carbon through the cycle when producers are eaten by consumers, and when decomposers break down dead and decaying matter into organic material. Phytoplankton- Biosphere: Phytoplankton are tiny marine organisms that are responsible for most of the transfer of carbon dioxide from the atmosphere to the ocean. They consume carbon during photosynthesis, and release it during respiration. Hydrosphere: Once carbon moves through photosynthesis and respiration, it becomes available to move back to the atmosphere, or dissolve back into ocean water. Ocean/Atmosphere Exchange- Biosphere: Most of the dissolved carbon gets used by other marine organisms in the biosphere, such as during photosynthesis or being converted into calcium carbonate to build shells and skeletons. Atmosphere: Some of the carbon dioxide stays as dissolved gas, which is released back into the atmosphere. Hydrosphere: Carbon dioxide from the atmosphere dissolved in the surface waters of the ocean. Photosynthesis (Ocean)- Biosphere: Many marine organisms in the biosphere use carbon to make calcium carbonate, a building material of shells and skeletons. Hydrosphere: Photosynthesis by tiny marine plants, such as phytoplankton, turn dissolved carbon from the atmosphere into organic matter in the sunlit surface waters of the ocean.
Describe how carbon is cycled through the steps below.
Step: Volcanoes- Volcanoes release carbon during eruptions and through underground magma flows in the form of carbon dioxide gas. Step: Atmosphere- As animals go through the process of cellular respiration, they release carbon into the atmosphere in a gaseous form as carbon dioxide. Step: Vegetation- Carbon in the form of carbon dioxide is taken in by plants during photosynthesis as they transform the carbon dioxide and water into glucose and oxygen. As plant matter decomposes, it creates organic carbon in soil and fossil fuels. Step: Soil & Organic Matter- Carbon is the main component of the organic matter in soil in the form of decaying plant and animal matter, micro-organisms, nutrients such as sugars, proteins, and organic acids. The decaying plant and animal matter trapped deep in the layers of Earth under intense heat and pressure create fossil fuels including oil, coal, and natural gas. Step: Surface Ocean- The ocean holds about 50 times more carbon than the atmosphere in the form of dissolved carbon dioxide. Carbon is quickly exchanged between the ocean and the atmosphere at the ocean's surface. Step: Sediment- Carbon may be stored for thousands of years deep on the ocean floor in sedimentary rocks and sediment in the form of carbonates.
How does the total amount of carbon on Earth compare to the amount of carbon in a specific sphere of Earth?
The amount of carbon on Earth has remained constant over time and is recycled through the spheres of Earth in the carbon cycle. Carbon is constantly traveling between the atmosphere, organisms, and Earth itself, with the majority of it stored in rocks and sediment. The amount of carbon in a specific place in the carbon cycle can change over time as carbon moves from one form to another and because Earth is a closed system, the total amount of carbon on Earth stays constant over time. However, the amount of carbon in a specific sphere of Earth or area can change due to human activity.
How is organic carbon created? How is the compound bonded together?
The carbon cycle is the process where carbon is moved and reused throughout Earth's spheres. The amount of carbon in a specific place in the carbon cycle can change over time as carbon moves from one form to another.
How have plants been affected by the excess amount of carbon dioxide in the atmosphere? Why are the long-term effects so serious?
The increase in atmospheric carbon dioxide has led to increased plant growth and a longer growing season. The increase in atmospheric carbon dioxide results in an increase in plant growth and longer growing seasons. While this may seem like a good thing in the short-term, the long-term effects are more serious. Larger plants with longer growing seasons require more water to survive. As temperatures continue to increase, water shortages may become increasingly more common. This can result in slowing of plant growth, plants taking in less carbon dioxide, or plants dying, and the stored carbon being released back into the atmosphere. * Land plants and oceans have taken up about 55% of the excess carbon dioxide, but the other 45% remains in the atmosphere, accounting for the rise in global annual temperatures. Plants on land have absorbed about 25% of the carbon dioxide emitted into the atmosphere. Recall that plants need carbon dioxide to grow, as well as water, sunlight, and nutrients.
Describe the key concepts from the video of the carbon cycle.
What is the carbon cycle? Carbon is the chemical backbone of all life on Earth. All of the carbon we currently have on Earth is the same amount we have always had. When new life is formed, carbon forms key molecules like protein and DNA. It's also found in our atmosphere in the form of carbon dioxide or CO2. The carbon cycle is nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again. Most carbon is stored in rocks and sediment, while the rest is stored in the ocean, atmosphere, and living organisms. These are the reservoirs, or sinks, through which carbon cycles. The ocean is a giant carbon sink that absorbs carbon. Marine organisms from marsh plants to fish, from seaweed to birds, also produce carbon through living and dying. Sometimes dead organisms become fossil fuels that go through combustion, giving off CO2, and the cycle continues.
Describe the path that organic carbon takes through the carbon cycle. Use photosynthesis as the starting point.
With photosynthesis, inorganic molecules of carbon dioxide are absorbed by plants in the biosphere and transformed into glucose which is organic. The process of photosynthesis releases oxygen into the atmosphere. Oxygen is an inorganic molecule that is used by animals during cellular respiration (The process within the mitochondria where chemical energy in the form of glucose is converted into chemical energy in the form of ATP). Carbon sources are processes that release more carbon than they absorb while carbon sinks absorb more carbon than they release. Burning coal to make electricity releases a large amount of carbon into the atmosphere and becomes a carbon source. Oceans absorb large amounts of carbon from the atmosphere making them a carbon sink. Animal respiration, microbe respiration, volcanic eruptions, and fossil fuel burning are all carbon sources because they release carbon. The other processes, like photosynthesis and sedimentation, absorb carbon, and therefore are carbon sinks. Together, all of the reservoirs, sources, and sinks make up the intricate and complicated carbon cycle. In general, the carbon cycle moderates the amount of carbon in any one reservoir, allowing the amount of carbon on Earth to remain constant throughout time. When left alone, the carbon cycle remains stable. But when anything changes the amount of carbon in any reservoir, the effects are felt throughout all reservoirs.
