Chemical Weathering and Carbon Dioxide Levels PDF

Chemical Weathering: Nature's Rock Sculptor Chemical weathering transforms Earth's surface through subtle yet powerful reactions. This process breaks down rocks, reshaping landscapes and influencing global climate patterns. Let's explore how chemical weathering works and its far-reaching impacts....

Chemical Weathering: Nature's Rock Sculptor Chemical weathering transforms Earth's surface through subtle yet powerful reactions. This process breaks down rocks, reshaping landscapes and influencing global climate patterns. Let's explore how chemical weathering works and its far-reaching impacts. by Oisin MC Manamon Chemical Weathering: Vocabulary Chemical The breakdown of rocks through chemical reactions, often Weathering involving water, gases, or acids. Carbon A greenhouse gas that traps heat in the atmosphere and Dioxide (CO₂) plays a role in weathering when dissolved in water Carbonic Acid A weak acid formed when CO₂ dissolves in water, (H₂CO₃) contributing to the chemical breakdown of rocks. Oxidation A chemical reaction where minerals in rocks react with oxygen, often resulting in rust. Dissolution The process by which minerals dissolve in water. Enhanced A technique where crushed rocks are spread over land to  Damaged letters (1/2) Some students are discussing why they can no longer read the lettering on a tombstone.  Damaged letters (2/2) Who do you agree with, and why? Jake: Rain has made the Nial: The stone is very old. stone soft so it has worn away. Ethan: The sun has faded the letters. Romesh: People have damaged the stone. Hamid: Rain has reacted with the stone.  Rain pH (1/2) 1 What is the pH of natural rainwater? A pH 7 B pH 6.5 C pH 5.5 D pH 8  Rain pH (2/2) 2 Why does rain have this pH? A Pollutants in the air make it acidic. B Carbon dioxide in the air makes it acidic. C Water is neutral. D Pure water is slightly acidic.  Timescales Estimate the timescale over which the chemical weathering of this tombstone has taken place. A 10 seconds B 10 minutes C 10 hours D 1 years E 100 years The Chemistry of Weathering Oxidation Oxygen reacts with minerals, causing rusting. Iron-rich rocks slowly turn reddish-brown. Dissolution Acidic water dissolves minerals. Limestone caves form through this process over time. Hydrolysis Water breaks down minerals. Clay forms as feldspars in granite decompose.  Weathered statues (1/2) Rainwater causes chemical weathering of limestone buildings. The damage to these statues at Wells cathedral can be clearly seen.  Weathered statues (2/2) Some students are discussing how the rain has damaged the statues. Elsie: The limestone has Ling: The rain has been eaten away by the dissolved the limestone. rain. Moira: The rain has Amie: The rain has made the limestone reacted with the soluble. limestone making a new substance that dissolves. Who do you agree with, and why?  Weathering differences? (1/2) Two new statues are made. One statue is made of limestone and the other is made of sandstone. 1 Which statue will weather more? A sandstone statue B limestone statue C neither  Weathering differences? 2 Why? A The stone is softer. B The stone is made of a different mineral that reacts more with acid. C The stone is weaker. D Both statues will experience the same conditions. CO₂: The Invisible Weathering Agent 1 CO₂ Absorption Atmospheric CO₂ dissolves in rainwater, forming weak carbonic acid. 2 Rock Reaction Carbonic acid reacts with rocks, especially limestone, releasing minerals. 3 Carbon Storage Released carbon is stored in soil, oceans, and sedimentary rocks.  Human Impact on CO₂ Levels Fossil Fuels Deforestation Rising CO₂ Levels Burning coal, oil, and Cutting down forests Human activities intensify natural gas releases stored reduces nature's ability to the greenhouse effect. This carbon. This increases absorb CO₂. Trees act as leads to global climate atmospheric CO₂. carbon sinks. change.  Burning methane (1/2) Methane is a fossil fuel. Methane gas is the fuel used in Bunsen burners. Gas-fired power stations burn methane gas. This type of power station releases carbon dioxide into the atmosphere.  Burning methane (2/2) 1 Some students are discussing why carbon dioxide is produced when methane burns. Jamila: Methane is a compound Stacey: When a fuel made of carbon and hydrogen atoms. burns it changes into When methane burns the carbon carbon dioxide. atoms join with oxygen atoms from the air making carbon dioxide. Ruby: Carbon dioxide Judy: Fuels are is released from a fuel made of carbon. when it burns. When fuels burn the carbon joins with oxygen to make carbon dioxide. Who do you agree with, and why?  Carbon dioxide molecules (1/2) Carbon dioxide is produced when petrol burns inside a car engine. The carbon dioxide molecules leave through the exhaust pipe and mix with other molecules that make up the air.  Carbon dioxide molecules (2/2) Some students are discussing where the carbon dioxide (CO2) molecules will spread. Charlie: The CO2 Taylor: The CO2 molecules will molecules will stay near spread into the air above the city. the exhaust. Jay: The CO2 molecules will rise Ali: Eventually the into the atmosphere CO2 molecules could above the city. spread anywhere in Earth’s atmosphere. Finn: The wind could blow the CO2 molecules away from the car exhaust.  Thinking about combustion 1 Some students are asked to explain why carbon dioxide is formed when methane burns. Each student thinks differently about methane burning. a Which ways of thinking may help a student to explain the formation of carbon dioxide? b Which ways of thinking may make it difficult for a student to explain the formation of carbon dioxide?  Measuring carbon dioxide (1/3) The graph shows the increase in atmospheric carbon dioxide measured at an observatory from 1960 to 2021.  Measuring carbon dioxide (2/3) 1 Where do you think the observatory is located? I am I think I think I am sure this is this is sure this is right wrong this is right wrong A industrial city B countryside C island in a large ocean  Measuring carbon dioxide (3/3) The carbon dioxide measurements were taken at the Mauna Loa Observatory, Hawaii. Chemical Weathering and Climate Change Natural CO₂ Removal Chemical weathering slowly removes atmospheric CO₂. It's a crucial part of Earth's carbon cycle. Accelerated Weathering Warmer temperatures increase rainfall and weathering rates. This process can't match current emissions. Feedback Loop Climate change affects weathering, which in turn influences climate. It's a complex relationship.  Warming oceans 1. What effect would an increase in 2. How would you explain your temperature have on the answer to question 1? dissolving of carbon dioxide in the oceans? Temperature does not affect the A More carbon dioxide will dissolve. A solubility of carbon dioxide in water. Increasing temperature increases B Less carbon dioxide will dissolve. B the solubility of carbon dioxide in water. The dissolving of carbon dioxide Increasing temperature decreases C will not be affected. C the solubility of carbon dioxide in water.  Changing levels of CO2 (1/2) The rate at which carbon dioxide is added to the atmosphere can be faster than, slower than or the same as the rate at which it is removed. 1 Which statement best explains why carbon dioxide levels in the atmosphere have increased? A The rate of addition has increased. B The rate of addition has been greater than the rate of removal. C The rate of addition has been equal to the rate of removal. D The rate of addition has been less than the rate of removal.  Changing levels of CO2 (2/2) 2 Which statement best describes the situation that could reduce carbon dioxide levels in the atmosphere? A The rate of addition decreases. B The rate of addition is greater than the rate of removal. C The rate of addition is equal to the rate of removal. D The rate of addition is less than the rate of removal.  What dissolves? (1/2) 1 Some students are asked which of the following substances dissolve in water. a Which substances do you think dissolve in water? A salt (sodium chloride) B sugar C copper sulfate D oxygen E carbon dioxide  What dissolves? (2/2) Home b The students share and discuss their answers. Neil: A,B and C. We dissolved blue Chris: A and B. Salt and copper sulfate crystals in our chemistry sugar dissolve when you lesson. Gases can’t dissolve. stir them into water. Angharad: A,B, C and D. Oxygen must Siobhan: A,B,C and dissolve in water D. Carbon dioxide is in because fish need fizzy drinks so it must oxygen. dissolve in water. Adil: All the substances can Who do you agree with, and why? dissolve so A,B,C,D and E. Do you still agree with your own answer? If not, why?  Fizzy water (1/2) Predict Will there be more fizzing when the warned water bottle is opened, or the chilled water bottle? Explain Why do you think this bottle will fizz more?  Fizzy water (2/2) Your teacher will open each bottle. Observe Describe the fizzing observed when each bottle is opened. Explain Were your prediction and explanation correct? Try to improve your first explanation to explain what happened more clearly. Reversing Climate Change: Nature and Technology Reforestation Planting trees absorbs CO₂. It's a natural, long-term solution to climate change. Enhanced Weathering Spreading crushed rocks accelerates CO₂ absorption. This mimics natural weathering processes. Carbon Capture Technology can remove CO₂ from emissions. It's stored underground or used industrially. Renewable Energy Solar, wind, and other clean energy sources reduce CO₂  Carbon dioxide removal 1. Which of these processes remove carbon dioxide from the atmosphere? A photosynthesis B respiration C combustion D dissolving  2.1.10 Chemical Weathering and Carbon dioxide levels Crit D. Summative Main Prompt: Di: The Problem: Define the problem of increasing CO₂ levels in the atmosphere. Reflect on how human activities Di: The Science: Explain how human activities (like burning fossil fuels and natural processes influence and deforestation) and natural processes (like photosynthesis and volcanic eruptions) affect atmospheric CO₂ levels. Use real-world data atmospheric carbon dioxide (CO₂) (e.g., from the Mauna Loa Observatory) to show how CO₂ levels have levels and evaluate solutions to changed over time. Include graphs or charts to illustrate key trends in CO₂ levels. mitigate (solve) these effects. Discuss the interaction between Dii: Impacts and Uses: Discuss the environmental, social, and economic impacts of rising CO₂ levels, such as global warming and science, technology, society, and climate change effects. Explain how understanding CO₂ levels the environment in the context of influences policies, technological developments, and individual behaviors. Evaluate at least two solutions to reduce CO₂ emissions CO₂ emissions. (e.g., renewable energy, reforestation). Consider the benefits and limitations of these solutions, like how effective and practical they are. Guiding Questions: How do the benefits and limitations of the proposed solutions Diii: Key Terms: List and define key terms related to the topic, affect their implementation on a global scale? In what ways do ethical considerations shape our response to rising CO₂ levels? Div: References: Provide a list of the sources you used for your How can scientific knowledge empower individuals and research, such as: Websites: Include URLs of reputable sites (e.g., societies to make informed decisions about CO₂ emissions? NASA, NOAA). Articles: Title, author, and publication details of any Be sure to understand the command terms (click here for articles or journals. Data Sources: Information from monitoring stations more information on command terms) like the Mauna Loa Observatory.  Di The Science Dii Impacts and Uses Di The Problem Diii Key Terms Div References