ELS SHS Unit 3 Introduction to Earth System Science PDF

Unit 3 Introduction to Earth System Science Table of Contents Table of Contents 1 Introduction 3 Essential Questions 4 Review...

Unit 3 Introduction to Earth System Science Table of Contents Table of Contents 1 Introduction 3 Essential Questions 4 Review 4 Lesson 3.1: Introduction to Earth System Science 5 Objectives 5 Warm-Up 5 Learn about It 6 Key Points 10 Web Links 11 Check Your Understanding 11 Challenge Yourself 12 Lesson 3.2: The Four Subsystems of Earth 13 Objective 13 Warm-Up 13 Learn about It 14 Key Points 17 Web Links 18 Check Your Understanding 18 Challenge Yourself 19 Lesson 3.3: Earth’s Climate System 20 Objective 20 Warm-Up 20 Learn about It 21 Key Points 23 Web Links 23 Check Your Understanding 24 Challenge Yourself 24 Lesson 3.4: The Biogeochemical Cycles 25 Objectives 25 Warm-Up 25 Learn about It 26 Key Points 30 Web Links 30 Check Your Understanding 31 Challenge Yourself 32 Laboratory Activity 33 Performance Task 35 Self Check 36 Key Words 36 Wrap Up 38 Photo Credits 39 References 39 Answer Key 41 2 EARTH AND LIFE SCIENCE | GRADE 11/12 Unit 3 Introduction to Earth System Science The photograph was taken by a NASA astronaut, Reid Weisman. He described it as one of his “favorite views from space,” while also mentioning that this was taken “just past sunrise over the ocean.” Weisman is a part of a crew of astronauts called Expedition 40 who were sent to space. Some of their missions include performing health checks on fellow astronauts and also upgrading the hardware and software of the humanoid robots. What else do astronauts in space do? The International Space Station (ISS) is an artificial satellite orbiting Earth that was built with the cooperation of different countries. Astronauts are sent to the ISS to perform different tasks, mostly for research. One of the main functions of the ISS is to provide weather information on Earth as well as data about space. The photograph above, for example, shows cloud thickness over a specific area. From this, meteorologists can predict the weather in the areas where the cloud formation 3 will pass. With such thick clouds, what do you think will the weather be in the next few days? The weather and climate affect different regions of the Earth. Since life is only known to exist on Earth, it is important that we study the weather and climate, as well as other processes that affect them. Earth is seen as a big system composed of smaller subsystems that interact with one another through different processes. Some scientists have theorized how these systems work for us to learn more about our planet. Essential Questions At the end of this unit, you should be able to answer the following questions. How is Earth changing? How organisms are affected by the changes occurring on Earth? How do the subsystems of Earth interact with one another? What factors influence weather and climate? How do Earth’s processes affect life forms? Review Earth is a complex system that is consist of living and nonliving components. Earth Science is the general branch of that deals with the physical components of Earth. It involves several branches such as Geology, Physics, and Atmospheric Science. Earliest observation about Earth’s nature started as early as 4th century BC when Aristotle observed Earth’s land composition changes in a very slow rate and it cannot be observed rapidly. 4  Lesson 3.1: Introduction to Earth System Science Objectives In this lesson, you should be able to: show the contributions of notable scientists on the understanding of Earth’s systems; and Cite reasons study of Earth’s systems is relevant to society. Many scientists have built the foundations for understanding Earth systems. Through intensive research, they were able to gather information about the past and present conditions of Earth. These efforts led to further learning about the parts and systems of our planet. What are some major contributions of these scientists to our knowledge of Earth? Warm-Up Carbon Footprint Calculator In this activity, you will calculate the amount of carbon dioxide emission you contribute due to your current lifestyle. Access the link below through your computer or smartphone. Carbon Footprint Calculator Trees for Life. 2014. ‘Kids Carbon Calculator.’ https://www.treesforlife.org.au/kids-carbon-calculator?PHPSESSID=069871de12 798d11433ffb559b5b64c4 5 Procedure: 1. Read the instructions carefully. 2. Only answer what is applicable. 3. Take note of the missing aspects that are applicable in Philippine context. 4. You may use the internet to calculate distances between places and the dates. Guide Questions: 1. How does your carbon footprint compare to the average adult? 2. Why is it helpful to know about your carbon footprint? 3. What two specific examples of carbon-emitting vehicles or activities are unique in the Philippine context that can be added to the activity. Learn about It Earth Systems Science (ESS) is an integration of the different scientific fields. It is the study of Earth as an integrated system. It seeks to understand the past, current, and future state of our planet. This connects physical and natural sciences while incorporating humanities fields, such as Sociology, Philosophy, and Psychology. The interdisciplinary nature of ESS led to the development of new ideas for research, as well as promoting scientific studies to people of different backgrounds. The more people learn about Earth, the greater the chances of adapting to the changes that will certainly come. Notable Scientists There are several prominent people who greatly contributed in establishing the current theories and principles that we acknowledge as part of Earth System Science. In this part, selected notable scientists in the field are enumerated. The study of human impact on other organisms and the environment led to the concept of sustainability, which is the capacity of Earth to continue to support human life without depletion of natural resources. One prominent person in this field is Vladimir Vernadsky, a Russian mineralogist and geochemist, who popularized the term noosphere or the sphere of human consciousness and reason. He theorized that the noosphere is the last of many stages in evolution of organisms. This is when human reason will provide further sustainable 6 development of both humanity and the global environment. Vladimir Vernadsky Alexander von James Hutton (1863–1945) Humboldt (1726–1797) (1769–1859) The transfer of heat around Earth through ocean currents influences greatly affect the types of organisms living in certain areas. This was thoroughly studied by Alexander von Humboldt, a 19th-century German geographer and naturalist, who helped establish the foundation for Earth system science through his observations of nature. He traveled to America and collected botanical, zoological, and geological specimens. With this, he successfully determined how distribution of life forms are affected by atmospheric and geophysical factors. James Hutton, the father of modern geology, was a Scottish farmer and naturalist. He conceptualized the process of weathering, wherein rock and soil are transformed through exposure to Earth’s atmosphere. He described how Earth was formed in a repeated cycle of erosion and sedimentation driven by heat from volcanic activities. Moreover, he introduced the concept of uniformitarianism, implying that the geological forces (such as those that trigger erosion and volcanic activities) in the past are the same as those in the present, making it possible to determine Earth’s history by studying rocks. James Lovelock, a British environmentalist proposed the Gaia hypothesis or Gaia principle, which is a postulate that Earth works as a self-regulating system. It proposes that all organisms and their habitats on Earth are closely integrated to 7 form a single and self-regulating system, where its components co-evolve to maintain and perpetuate life forms. He cited that this was evident in photosynthetic cyanobacteria during the Precambrian period that modified Earth’s atmosphere to become oxygen-enriched. This change in the atmosphere then supported the evolution of more complex organisms. Lynn Margulis, an American biologist and evolutionary theorist, further developed Lovelock’s Gaia hypothesis. Margulis noticed that all kinds of bacteria release gases as by products and hypothesized that atmospheric gases were from biological sources. She collaborated with Lovelock and published a paper on how life regulates the temperature and chemical composition of the soil and the atmosphere. This led them to modify Gaia hypothesis into its more widely accepted version stating that life influences planetary processes. James Lovelock Lynn Margulis (born 1919) (1938–2011) NASA Involvement In 1983, the National Aeronautics and Space Administration (NASA) formed Earth System Science Committee. NASA began to study the components of Earth’s systems, their linkages, dependencies, and fluxes. NASA scientists aim to understand Earth’s systems by using satellites for long-term observations. Information from the space give scientists a different perspective, which aids in conducting their research. 8  Fig. 1. The International Space Station. Relevance to Society All things around us are built upon the subsystems of Earth. All parts of the human history happened on Earth’s crust. Understanding the physical and chemical attributes of Earth is highly essential for the advancement of human lives in the planet. Nowadays, Earth is rapidly evolving. These changes can be good but most 9 negatively affect life forms. Understanding how Earth behave and change over time could help human on how to properly adapt for survival. A good example for the application of Earth system science in real life is the use of Climate change data in drafting policies for proper conservation of different ecosystems in the planet. The information provided by the scientists were useful in guiding policy makers to construct and implement rule to hinder adverse effects of climate change. Moreover, Earth system science is important exploring possibilities outside Earth. Knowing the complete nature of our planet allows humans to explore other planets on space that could provide essential needs of living organisms. Lastly, Earth system science embodies limitless boundary of human curiosity in understanding its surroundings. Key Points Vladimir Vernadsky theorized that the development of human thought and reason have had a great impact on other living things, leading to studies on sustainability. Alexander von Humboldt thorough study on the locations of plant, animal, and geological specimens and their interactions led to the knowledge of underlying processes such as the movement of heat in ocean currents, and the effect of temperature on living things. James Hutton’s introduction of uniformitarianism made it possible for scientists to determine the history of Earth by studying rocks. James Lovelock and Lynn Margulis collaborated on the development of the Gaia hypothesis, proposing that life regulates the temperature and chemical composition of the soil and atmosphere. A major landmark in the formal development of Earth System Science was the formation of Earth System Science Committee by NASA in 1983. Through the use of satellites, NASA is able to provide more information to scientists to help in the studies of Earth’s systems. Knowledge on Earth System Science is essential to understand Earth’s components that are essential in our daily lives and useful in drafting policies for conservation of our planet. 10  Web Links For further information, you can check the following web links: Know more about NASA’s Earth Observing System. NASA. 2017. ‘NASA’s Earth Observing System.’ https://eospso.nasa.gov Take a view of Earth through the cameras onboard the International Space Station. NASA. n.d. ‘International Space Station on UStream.’ https://www.nasa.gov/multimedia/nasatv/iss_ustream.html Read about the life and works of James Lovelock, the man who introduced the Gaia hypothesis. Lovelock, et. al. 1973. ‘Atmospheric Homeostasis by and for the Biosphere: The Gaia Hypothesis.’ http://www.jameslovelock.org/atmospheric-homeostasis-by-and-for-the-biosphere-t he-gaia-hypothesis/ Check Your Understanding A. Write yes if the human activity leads to sustainability. Otherwise, write no. 1. Collecting rainwater for use in watering plants. 2. Using a plastic straw when ordering a drink. 3. Throwing a plastic bottle into the ‘biodegradable’ trash bin. 4. Keeping the faucet open when brushing teeth 5. Choosing to walk if the destination is near and the weather is good. 6. Buying shampoo in big containers instead of small packs. 7. Using a reusable water bottle in school instead of plastic cups. 8. Throwing food wrapper directly to sewage if there is no available trash can. 9. Using recyclable materials for school projects. 10. Leaving appliances on even no one is using them. B. Identify the notable scientist involved. Write only the last name. 11  1. ___________ cited that atmospheric gases came from organisms. 2. ___________ observed that certain organisms lived in specific environments. 3. ___________ proposed that a change in the atmosphere led to evolution. 4. ___________ suggests that humans consciousness affects other organisms. 5. ___________ proposed Earth’s landscape continues to change the same way as before. C. Write true if the statement is correct. Otherwise, write false. 1. James Hutton proposed that volcanic activity is the driving force behind the changes on Earth’s surface. 2. Alexander von Humboldt established the relationship between cyanobacteria and the increase of oxygen in the atmosphere. 3. According to the Gaia hypothesis, Earth is a sphere of human reason. 4. The term noosphere refers to Earth as a self-sustaining system. 5. Margulis cited gas production of all bacteria as evidence to support the Gaia hypothesis. Challenge Yourself Answer the following questions. 1. Why should humans take more responsibility for Earth’s sustainability? 2. What are some ways you can do to help maintain Earth’s sustainability? List three practices. 3. Why is the use of satellites important when studying Earth’s systems? 4. At first glance, do you agree with the Gaia hypothesis? Why or why not? 5. If given the chance as an astronaut, what would you focus on first? 12  Lesson 3.2: The Four Subsystems of Earth Objective In this lesson, you should be able to: describe each major subsystem of Earth. To further understand Earth as a system, you need to understand the different subsystems of our planet. The four major subsystems of Earth are the atmosphere, geosphere, hydrosphere, and biosphere. The word sphere comes from the Greek word sphaira, which means globe or ball. Each sphere is comprised of matter that are similar in nature, which is also the basis for their names. What makes each sphere unique? Warm-Up Order Please! The activity will demonstrate what happens inside a fast food restaurant, where each student will pick a role. The demonstration will start when a customer orders food and will end after serving the food to the customer. Procedure: 1. Randomly assign the following roles: a. cashier b. kitchen crew 1 (receives the order) c. kitchen crew 2 (prepares the food) 13  d. kitchen crew 3 (cleans the tables) e. store manager (coordinates activities and handles problems) f. customers (all other students are customers) 2. Give the class three minutes to plan their demonstration. 3. Proceed with the class demonstration. 4. Let each student answer the guide questions. Guide Questions: 1. Why are there roles for each employee in the restaurant? 2. What do these roles tell you about a system? 3. How are these roles similar to the systems of Earth? Learn about It Earth is a complex self regulating system that is consists of four major subsystems, namely: atmosphere, hydrosphere, geosphere, and biosphere. Each subsystem plays important roles in maintaining balance and equilibrium in Earth’s system. At the same time, each subsystem has unique components that made them highly different from one another. Atmosphere The atmosphere makes up of all the gases on Earth. Its name comes from the Greek word atmos, which means gas. It has no specific boundary but an imaginary line called the Karman line separates the atmosphere and outer space. The most abundant gas is nitrogen, which makes up 78.1% of the atmosphere. Oxygen comes second at 20.9%, and argon, a noble gas, is at 0.9%. Lastly, carbon dioxide and the rest of the gases combined constitute 0.1%. The atmosphere has different layers: troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Each layer has its own set of special features that make it different from each other. The troposphere extends to about 14.5 km above the surface of Earth. It is the lowest layer where the weather disturbances occur. The stratosphere is found 14.5 to 50 km above Earth’s surface. The ozone layer that protects Earth from the sun’s harmful UV radiation is part of this layer. 14  The mesosphere extends from 50 to 85 km above Earth’s surface. It protects Earth from the impact of space debris. The coldest temperatures on Earth, at -90°C are found near the top of this layer. The thermosphere is found 85 to 600 km above Earth’s surface. It has charged particles that are affected by Earth’s magnetic field. The particles create the Auroras or Northern and Southern lights. Many satellites also orbit Earth in this layer. The exosphere is the outermost layer. It extends to about 10 000 km above Earth’s surface, though there is no clear boundary where the exosphere ends and space begins. Fig. 2. Layers of the atmosphere. Geosphere Geosphere comes from the Greek word geo which means ground. It includes all the soil, rocks, and minerals present in the crust to the core of Earth. It is divided into three layers, namely: crust, mantle, and core. 15 The crust is the outermost layer of the geosphere. It is made mostly of silicate materials. There are two different types of crust, the oceanic and continental crusts. The oceanic crust lies beneath the oceanic floors which is about 5 to 10 km thick. On the other hand, the thicker continental crust makes up the continents and is about 15 to 70 km thick. The boundary between the crust and mantle is known as the Mohorovicic discontinuity or Moho. This was named after the Croatian scientist, Andrija Mohorovicic. Fig. 3. Internal structure of Earth The mantle is a 2 900 km thick layer below the crust that is mostly made up of silicate rocks rich in magnesium and iron. Mantle’s temperature increases with its depth. The layer directly below the crust has the lowest temperature and soft enough to allow plates of the crust to move. On the other hand, the layer with the highest temperature is found in contact with the heat-producing core. Based on its mineral composition and the type of deformation, the mantle can divided into several layers. The uppermost mantle is cold and brittle, and together with the crust forms the lithosphere, the hard rigid outermost layer of Earth. It is broken up into tectonic plates. The asthenosphere is the layer directly beneath the lithosphere is hot enough to flow and minimally melt, allowing the lithospheric or tectonic plates above to move. The lower mantle is hotter and denser than the upper mantle but it remains solid because of the immense pressure. The core, which has a radius of 3 480 km, is the innermost layer of Earth. It is made up of iron and nickel. It is comprised of two layers, the outer core and the inner 16 core. These two regions are separated by a boundary called Bullen discontinuity. Hydrosphere Hydrosphere comes from the Greek word hydro which means water. It is composed of all water on Earth in any form: water vapor, liquid water, and ice. It is comprised of 97.5% saltwater and 2.5% freshwater. It includes all bodies of water such as oceans, lakes, rivers, and marshes. Clouds and rain are also part of the hydrosphere. Biosphere Biosphere comes from the Greek word bio which means life. It is comprised of all living things. It includes all microbes, plants, and animals. It extends to the upper areas of the atmosphere where insects and birds can be found. It also reaches the deep parts of the oceans where marine organisms can still survive. Organisms interact with other organisms and the physical environment. They form communities called biomes. Biomes exist all over the world. Examples of biomes include deserts, tropical rainforests, swamps, or coral reefs. Key Points There are four primary subsystems of Earth: atmosphere, geosphere, hydrosphere, and biosphere. ○ The atmosphere is made up of various gaseous elements. ○ The geosphere is composed of all the soil, rocks, and minerals from the surface of Earth up to its interior. 17  ○ The hydrosphere includes all form of water bodies on Earth. ○ The biosphere includes all living things on Earth. Web Links For further information, you can check the following web links: Do a tour about the cryosphere, a part of the hydrosphere that is composed of all of Earth’s frozen water. NASA. 2009. ‘A Tour of the Cryosphere.’ https://www.youtube.com/watch?v=_WUpjXHo-O4 Know more about the Marianas trench, the deepest known point in Earth’s oceans other trenches Cheryl Dybas (National Science Foundation). 2014. ‘Scientists Explore One of Earth's Deepest Ocean Trenches.’ https://phys.org/news/2014-04-scientists-explore-earth-deepest-ocean.html Check Your Understanding A. Match the item to the sphere where it belongs by checking the box under its field. Atmosphere Geosphere Hydrosphere Biosphere Eagle Oxygen gas Pasig River Mayon Volcano Mango Laguna de Bay Neon lights 18  Batanes Islands Bacteria Aurora borealis B. Identify the following. 1. It is how water moves in the oceans. 2. It is the combination of the crust and upper mantle. 3. It is the process where water moves into the atmosphere. 4. It is where water in the oceans is warmed. 5. It is the innermost layer of Earth’s interior. 6. All living things are part of this sphere. 7. It is the layer of the atmosphere where weather occurs. 8. It is the type of crust found under the oceans. 9. It makes up 97.5% of all the water on Earth. 10. It is the most abundant gas in the atmosphere. Challenge Yourself Answer the following questions. 1. What are some ways you can do to conserve water in your home or school? 2. With the ocean levels continually rising, cities and towns are in danger of being flooded. If you have the resources, which would you build: an underwater building or a high-rise building? Explain your answer. 3. Areas near volcanoes are good farmland candidates due to good soil fertility. If you owned a farmland near a volcano, what would you do to keep your farm working and safe at the same time? 4. When bottled water is taken from a refrigerator and exposed to air, the outside of the bottle also gets wet. Explain why this happens. 5. Soil is considered fertile when it is rich in nutrients. What are some effects when water runs through this soil? 19  Lesson 3.3: Earth’s Climate System Objective In this lesson, you should be able to: explain how the subsystems interact with external forces and affect Earth’s climate system. The weather and climate are common concerns with regards to conversation. Changes in climatic conditions are evident in seasonal variations over a year. These can affect earth system process and life forms.. What causes the changes in Earth’s climate? Warm-Up A Picture of You Materials: a picture of a terrestrial or a marine ecosystem pictures of other ecosystems, depending on the class size. Procedure: 1. Divide the class into groups of 3 to 4 students. 2. Assign a picture of an ecosystem to each groups. 3. The students should analyze the picture and list down two parts of the ecosystem that are members of the four major subsystems of Earth. Guide Questions: 1. Describe the ecosystem assigned to you. What is the condition of the atmosphere, hydrosphere, geosphere, and biosphere present in the picture? 2. What parts of the ecosystem are members of the four major subsystems of Earth? 3. How are the four major spheres connected to each other? 20  Learn about It Weather and Climate Weather is the fluctuating state of the atmosphere over a short period of time. Describing the weather includes stating the temperature, wind speed and direction, type of precipitation, and type of clouds. Climate on the other hand, is the average weather over a certain period and area. It varies depending on latitude, distance to large bodies of water, and geography. The climate system of Earth is an interactive system consisting of the interactions of the atmosphere, hydrosphere, biosphere, and geosphere. Earth’s Subsystems and Climate The atmosphere is considered the most uneven, unstable, and fast-changing part of the climate system. Nitrogen (N2) is the most abundant gas in the atmosphere, followed by oxygen (O2). These gases do not have significant interaction with the radiation from the sun. However, trace gases such as water vapor (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O,) and ozone (O3) absorb and emit radiation. These trace gases are called greenhouse gases. Greenhouse gases tend to increase the temperature of Earth’s surface because they absorb the outgoing radiation from the surface and reemit them into the atmosphere. Water vapor is considered as the primary greenhouse gas because it is the most variable component of the atmosphere. Water in the atmosphere undergoes different phase changes such as evaporation, condensation, and sublimation. The transitions between these phases result in continuous absorption and emission of energy in the atmosphere. The hydrosphere influences the climate system by storing and transporting large amounts of energy. The oceans, which cover approximately 70% of Earth’s surface, act as climate regulator because they strongly influence the temperature changes. These oceans absorb the majority of sunlight that reaches Earth’s surface. 21 Soil and vegetation at the land surface of the geosphere affect climate by controlling how much energy received from the sun is returned to the environment. Soil moisture greatly affects surface temperature because the evaporation of water from the soil requires energy. The part of the geosphere that affects climate is the crust. The topography or the description of the surface feature of the land affects the wind that blows on the land surface. An area may be a part of any of the different landforms, such as plains, hills, valleys, and mountains. A mountain range may block the path of low altitude clouds, affecting the weather in surrounding areas. The temperature at sea level may also differ from the temperature on elevated places. Dust from land may also be blown into the atmosphere and may interact with the radiation. The biosphere has significant effect on the atmosphere’s composition. Photosynthesis allows the release of oxygen and uptake of carbon dioxide; hence, organisms take part in the exchange of greenhouse gases. Removing large number of plants and trees in an area can cause an increase in free carbon dioxide due to less plant absorbers. In long term, this may affect the climate over the area. This usually occurs in highly urbanized areas, especially ones with industrial facilities, such as factories and manufacturing plants. 22  Key Points The four major subsystems affect the weather and climate on Earth. Atmospheric condition is affected by the greenhouse gases present, especially water vapor. The hydrosphere influences the climate system by storing and releasing large amounts of energy in the oceans, which act as climate regulators. The different landforms affect the climate by acting as physical barriers for clouds and storms, and when dust is blown into the atmosphere and affect the amount of radiation from the sun Photosynthesis affects the climate system by absorbing carbon dioxide and providing oxygen. Web Links For further information, you can check the following web links: Find out how a storm forms in the ocean. National Geographic. 2011. ‘Hurricanes 101.’ https://www.youtube.com/watch?v=zP4rgvu4xDE Test your if you are prepared for any disaster by building an emergency kit. Play this game and see if you can make an emergency kit from the items around you. Ready Campaign - Department of Homeland Security. n.d. ‘Build a Kit.’ https://www.ready.gov/kids/games/data/bak-english/index.html 23  Check Your Understanding A. Complete the table below by writing an example of an interaction between two subsystems. Atmosphere Geosphere Hydrosphere Biosphere Atmosphere Geosphere Hydrosphere Biosphere B. Write true if the statement is correct. Otherwise, write false. 1. Wet soil lowers surface temperature. 2. Greenhouse gases allow heat to escape the atmosphere. 3. Oceans release heat throughout Earth. 4. Mountain chains affect weather by absorbing heat. 5. Animals affect the atmosphere by releasing carbon dioxide. Challenge Yourself Answer the following questions. 1. What human activity has a positive effect on each of the four subsystems? Explain each effect. 2. Most of Earth’s freshwater is frozen in glaciers and the polar regions. What would happen to our freshwater supply if the average temperature of Earth increases? 3. How does planting more trees affect the climate of an area? 4. What are the conditions needed for a garden to grow well? Explain how the interactions of the four subsystems play a role on this. 5. If an earthquake occured, how would this affect the other spheres? Cite one effect for each. 24  Lesson 3.4: The Biogeochemical Cycles Objectives In this lesson, you should be able to: identify some of the biogeochemical processes that take place on Earth; and describe the movement of matter such as water, nitrogen, carbon dioxide, and oxygen in their respective cycles. Earth’s subsystems are consists of several compounds like water, nitrogen, carbon, and oxygen that are essential to sustain life. Interactions between the subsystems and living organisms allow recycling of these materials to make Earth a self regulating system. How do plants take carbon dioxide and water from its environment then return it in the form of oxygen and carbon-based materials? Why is it important to sustain the exchange of materials between organisms and Earth’s systems? Warm-Up The Story of a Leaf Watch the video below. You may also read the printed version of the fable, The Fall of Freddie the Leaf: A Story of Life for All Ages by Leo Buscaglia (1982). The Fall of Freddie the Leaf User: Susan Striker. 2017. ‘The Fall of Freddie the Leaf.’ https://www.youtube.com/watch?v=lnlSI9KyrDc Guide Questions: 1. In the story, what happens to the leaves that falls? Describe each process. 2. What usually happens to leaves in nature? 3. Do the withered leaves go back to nature? How? 25  Learn about It A biogeochemical cycle is a complete path an element or a compound takes through the four subsystems of Earth—atmosphere, geosphere, hydrosphere, and biosphere. The name “biogeochemical” implies the involvement of life (bio-), Earth’s surface (geo), and substances (chemical) present on Earth. These processes are essential for the maintenance of life on Earth. Biogeochemical cycles include water, nitrogen, carbon dioxide, and oxygen cycles. Water Cycle The movement of water from the ocean to the atmosphere to land and back to the ocean is called the water or hydrologic cycle. This movement is aided by the processes of evaporation, condensation, precipitation, and runoff. Fig. 7. The water cycle. 1. Evapotranspiration. The sun heats up bodies of water, such as oceans and rivers, and also moisture from land and vegetation. Water undergoes evaporation. It transforms from liquid to gas. Also, plants release water vapor through the pores under the leaves in the process known as transpiration. These two processes are sometimes coined together to refer to the process that transfers water from land to the atmosphere called evapotranspiration. 26  2. Condensation. Lighter water vapor cools as it reaches a certain altitude, and forms tiny floating droplets. As a result, clouds form. This process is called condensation. Clouds are not the only manifestation of condensation. Ground-level fog and glasses fogging up in rooms also result from this process. 3. Precipitation is the release of water from clouds in the form of rain, sleet, hail or snow. For this to happen, water droplets must collide with each other or condense on smaller dust, salt, or smoke particles which serve as the nucleus. Around 60% of precipitation on land evaporates back to the atmosphere each year while 40% returns to the ocean as runoff. Nitrogen Cycle The nitrogen cycle is the movement of nitrogen between the four spheres. It involves the conversion of nitrogen into various forms. Nitrogen, which makes up approximately 78% of the atmosphere, is essential to life’s protein synthesis. Organisms can’t use molecular nitrogen directly that is why conversion of this element into other forms is vital. The nitrogen cycle involves nitrogen fixation, nitrification, ammonification, and denitrification. 1. Nitrogen fixation is the process of converting atmospheric nitrogen into biologically available nitrogen (ammonium compounds). Molecular nitrogen (N2) is a very stable compound due to the strong bond between the two nitrogen atoms. Hence, the bond requires a large amount of energy to break. Only a selected group of prokaryotes can carry out reactions that break such bond. These prokaryotes are called nitrogen-fixing bacteria. 2. Nitrification is a process that converts ammonia and ammonium 27  compounds into nitrite and then to nitrate. Most nitrification process occurs aerobically (requires oxygen) and is carried out exclusively by prokaryotes. The nitrates and nitrites are utilized by land plants and algae in water bodies. Plants, algae, and bacteria then convert the inorganic forms of nitrogen compounds through different chemical reactions. Fig. 8. The nitrogen cycle. 3. Ammonification is the process where fungi and prokaryotes decompose the dead tissue of organisms and release the inorganic nitrogen back into the ecosystem as ammonia. It is also known as nitrogen mineralization. 4. Denitrification involves the process of releasing nitrogen back to the atmosphere. Through denitrifying bacteria, organic compounds from dead organisms are converted back to ammonia, nitrate, or molecular nitrogen. Carbon-Oxygen Cycle 28 The carbon cycle is a rather complex cycle. Carbon is present in many forms ranging from compounds found in living organisms to fossil fuels. Carbon, in its gaseous state in the form of carbon dioxide (CO2) and methane (CH4), enters the atmosphere through respiration, combustion or burning of organic compounds, and diffusion from the ocean. Fig. 9. The carbon cycle. Photosynthesis of plants and photosynthetic bacteria and diffusion into the oceans remove carbon from the atmosphere. Photosynthesis is the process by which organisms convert carbon dioxide and water from the environment into glucose and oxygen. From the land, carbon reaches the oceans through rivers and streams in the form of dissolved carbon, organic compounds, or particulates like calcium carbonate shells. Carbon from dead organisms which are buried in wetlands, swamps, lakes and deep-sea sediments for a very long period of time is converted into fossil fuels. One unique characteristic of Earth is the presence of free molecular oxygen in its atmosphere. Simple and complex processes both on the surface and beneath Earth determine the amount and distribution of O2. This distribution can be visualized through the oxygen cycle. Oxygen is distributed among reservoirs including the atmosphere, oceans, freshwater environments, soils, and groundwater. The major mechanism that produces oxygen gas is photosynthesis which occurs in plants, algae, and in two groups of prokaryotes (cyanobacteria and 29 prochlorophytes). Diffusion also takes place between the atmosphere and the surface waters. Oxygen is consumed through aerobic respiration, a process which produces energy for the organisms. Other processes include metabolism and oxidation. Key Points The biogeochemical cycles transfer elements and compounds between the four spheres. These transfers are essential in making the planet habitable. Water, carbon, and nitrogen cycle are important biogeochemical processes that describe how the substance is transported through each sphere. Web Links For further information, you can check the following web links: Read more about nitrogen, including how humans impact the nitrogen cycle, and its effect on human health. Fields, Scott. ‘Global Nitrogen: Cycling out of Control.’ Environmental Health Perspectives 112.10 (2004): A556–A563. Print. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1247398/ Test your knowledge of photosynthesis by taking this short interactive quiz. Scripps Institution of Oceanography. n.d. ‘Photosynthesis diagram.’ http://earthguide.ucsd.edu/earthguide/diagrams/photosynthesis/index.html Know more about the formation of fossil fuels and how much is left for humans to use. BBC Earth Lab. 2017. ‘Will Fossil Fuels Run Out?’ https://www.youtube.com/watch?v=jjfs_7kwRks Check Your Understanding 30 A. Fill in the blanks with the correct answer. 1. Transpiration occurs when water vapor goes through _________________. 2. Precipitation is the release of water from clouds in the form of _______. 3. The condensation of water vapor results into the formation of _____. 4. The process of converting atmospheric nitrogen into an ammonium compound is called ____________________. 5. Nitrification is the process of converting ammonia and ammonium compounds into __________ then to __________. 6. Nitrification is __________ process which means that it requires oxygen which is carried out exclusively by __________. 7. When fungi and prokaryotes decompose the dead tissue of organisms, they release the nitrogen into the ecosystem in the form of __________. 8. Denitrification is the process of releasing nitrogen into _______________. 9. The gaseous states of carbon are in the form of _____ and _____. 10. Carbon in dead organisms that have been buried for a long time under the ground are converted to _______________. B. Specify Earth’s system involved on each cycle by putting check on the provided boxes below. Substance Atmosphere Geosphere Hydrosphere Biosphere water nitrogen oxygen carbon Challenge Yourself Answer the following questions. 31 1. How are the oxygen and carbon cycles connected? 2. How important are the roles of prokaryotes, fungi, and bacteria in the nitrogen cycle. 3. Why is it important to conserve water even if there is a lot of water available? 4. How are plants involved in all the cycles discussed in the lesson? 5. Based on this lesson, what is your opinion of the Gaia hypothesis stating that Earth is an entire self-regulating system? 32  Laboratory Activity Activity 3.1 Greenhouse Bottles Objectives At the end of this laboratory activity, the students should be able to: simulate the greenhouse effect using simple materials; explain how the greenhouse effect works; and describe how greenhouse effect affects the hydrosphere. Materials and Equipment 2 clear 1.5-liter plastic bottles 2 sheets 8.5x11 white paper 1 plastic cup 4 rubber bands water clear plastic wrap or clear scissors or cutter plastic cover masking tape 2 glass thermometers or room white cardboard thermometers Procedure 1. Cut the plastic bottle ¾ from its base. Do the same for the other bottle. Label each bottle as Bottle 1 and Bottle 2 respectively. 2. Cut a rectangle from the cardboard, making sure that the entire length of the thermometer can fit. 3. Tape the thermometer on the white side of the cardboard. make sure that the scale is facing outside, not facing the cardboard. tape the thermometer on the parts without the lines of the scale. 4. Wipe the bottles dry, then tape the thermometer on the inside of bottle. Make sure that the thermometer is facing outside and that the tip of the thermometer is not touching the wall of the bottle. 5. Place each bottle on a sheet of white paper under direct sunlight, making sure that the thermometer can be read from outside. The thermometers should not be exposed to direct sunlight so adjust the bottle accordingly. 6. Fill up the plastic cup with water and place it inside bottle 2, opposite the thermometer. 33  7. Cover the opening of each big bottle with the clear plastic wrap. Use the rubber bands to seal the plastic wrap. 8. Read and record the temperature on each bottle every five minutes for 30 minutes. Write your observation on the data sheet. 9. Adjust the positions of the water bottles, making sure that the bottles are exposed to direct sunlight all the time. Data and Results Table 1. Temperature inside water bottle. Bottle Time (in minutes) no. 5 10 15 20 25 30 1 2 Guide Questions 1. How are Bottle 1 and Bottle 2 different from each other? 2. What happened to the temperature in Bottle 1? Bottle 2? 3. Compare the temperature range for each bottle. Is there a difference between the two ranges? Explain why or why not. 4. How did the water affect the temperature in Bottle 2? 5. If you lived near a body of water, such as the seaside or near a lake, what effect would the water have on the temperature during the dry season? How about during the rainy season? 6. How is the greenhouse effect demonstrated in the experiment? 34  Performance Task My Journey on Earth Goal The task is to create a photo album of the journey of a substance in one of the biogeochemical cycles. You may choose from water, carbon dioxide, oxygen, or nitrogen. Role The students will take on the role of the substance as a tourist in the different spheres. They will take pictures of the substance in each sphere. They may make their own situations on this. Audience The target audience is a tourist company that promotes Science in its promoted destinations. Situation The students will try to integrate their lesson on biogeochemical cycles and the major subsystems in the promotion of tourist destinations. Product, Performance, and Purpose The students will produce a photo album or powerpoint presentation to show their photos, complete with captions or write-ups. Standards and Criteria Your performance will be graded by the following rubric. Needs Successful Exemplary Below Expectations, Criteria 0% to 49% Improvement Performance Performance 50% to 74% 75% to 99% 100% Content Information is Information is Information is Information is accurate and accurate and accurate but inaccurate and complete, with complete. incomplete. incomplete. added correct information 35  Organization Presentation is Presentation is Presentation is Presentation is highly organized. organized. organized with a disorganized. few disarranged information. Presentation Presentation is Presentation is Presentation is Presentation is creative with a creative with a creative with a creative with a high degree of considerable moderate degree limited effectiveness effectiveness of effectiveness effectiveness Self Check Put a check on the box provided below if you are confident to execute the given learning outcome in each row. Check I can… explain how Earth is changing. differentiate the major subsystems of Earth. describe the interactions among the major subsystems of Earth. relate the interactions among the major subsystems to Earth’s climate system. describe how each biogeochemical cycle is able to support life on Earth. Key Words Gaia hypothesis It is also known as the Gaia principle, which proposes that all organisms and interact and affect their surroundings to form a self-regulating system. This system maintains the conditions for life on Earth. Geography It is a field of Science that focuses on the physical 36  features of places on Earth and its relationship and interactions with people. Geology It is a field of Science that deals with the history of Earth and the life that has existed on it, especially as recorded in rocks. Global warming It is an increase in Earth’s atmospheric and oceanic temperatures due to an increase in the greenhouse effect. Greenhouse gas It is any gaseous substance that traps heat in the atmosphere and contributes to the greenhouse effect. Karman line It is the height considered as the boundary between the atmosphere and space. It is found at almost 100 km from the ground. Mohorovicic It is the boundary between the crust and the mantle. discontinuity Noosphere It is the sphere of human thought popularized by Vladimir Vernadsky. He proposed that the noosphere greatly affects the biosphere and thus, the geosphere. Ocean current It is the movement of ocean water from one place to another because of wind, tides, and differences in temperature and salinity. Prokaryotes These are unicellular organisms that lack a nucleus and other organelles inside the cell. These include cyanobacteria, which are photosynthetic bacteria involved in the nitrogen cycle. Sustainability It is the ability to be maintained at a certain level. When applied to Earth systems, it is the capacity of Earth to maintain life without greatly depleting its natural resources. System It is a collection of different and interdependent parts enclosed within a defined boundary. Tectonic plates These are massive, irregularly shaped plates that make up the crust. Over long periods of time, tectonic plates move around and change, and these changes occur near plate boundaries. Earthquake and volcanic activity are concentrated around these plate boundaries. 37 Uniformitarianism It refers to the theory that throughout natural history, there are forces and processes that have shaped earth’s landscape and these forces and processes have not changed and continue to occur. Volcanic activity is said to be the driving force of these changes. Wrap Up The Study of Earth System Science 38  Photo Credits Fig 2. James Lovelock (1919-) 04 by MRC National Institute for Medical Research is licensed under CC BY 3.0 via Wikimedia Commons; Lynn Margulis by Jpedreira is licensed under CC BY-SA 2.5 via Wikimedia Commons. Fig 3. International Space Station by the National Aeronautics and Space Administration. References Botkin, Daniel B. and Keller, Edward A. 2011. Environmental Science Earth as a Living Planet. USA: John Wiley and Sons, Inc. Tarbuck, Edward J. and Lutgens, Frederick K. 2015. Earth Science. 14th edition. Pearson Education Inc. United States Geological Survey. “Precipitation: The Water Cycle.” Last modified December 2, 2016. Accessed February 8, 2017. http://water.usgs.gov/edu/watercycleprecipitation.html Marshak, Stephen. 2009. Essentials of Geology 3rd Edition, New York: W.W. Norton & Company. Hefferan, Kevin, and John O’Brien. 2010. Earth Materials. UK: Wiley-Blackwell. NASA. “International Cooperation.” Accessed April 3, 2018. https://www.nasa.gov/mission_pages/station/cooperation/index.html NASA. “Astronaut Requirements.” Accessed April 3, 2018. https://www.nasa.gov/audience/forstudents/postsecondary/features/F_Astro naut_Requirements.html Prothero, Donald R., and Robert H. Dott, Jr. 2010. Evolution of the Earth. New York: 39  McGraw-Hill. University of Colorado Boulder. “Biogeochemical Cycles.” Accessed April 3, 2018. https://www.colorado.edu/GeolSci/courses/GEOL1070/chap04/chapter4.html University Corporation for Atmospheric Research. “Layers of Earth’s Atmosphere.” https://scied.ucar.edu/atmosphere-layers University of Michigan’s Global Change Courses. “A Goddess of the Earth? A Debate over the Gaia Hypotheses.” Accessed April 3, 2018. https://globalchange.umich.edu/globalchange1/current/lectures/Gaia/index. html Utah State University. “Trees and Climate Change.” Accessed April 4, 2018. https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2783&context=e xtension_curall 40