Understanding Systems and Models in IBESS

This movie covers subtopic 1.2, Systems and Models, under the main topic of IBESS topic 1, Foundations of Environmental Systems and Societies. The significant ideas for this subtopic are, a systems approach can help in the study of complex environmental issues. The use of models of systems simplifies interactions, but may provide a more holistic view than reducing issues to single processes. The title of this course is environmental systems and societies, not environmental science or environmental studies. We will approach each topic in this course under the concept of systems. So let's start with a brief discussion of systems. A system is a set of connected things or interrelated parts working together to make a complex whole. You You might recall these images from topic 1.1. In this image, there are several systems. One could be the tree. There are many parts of this tree that work together to allow it to photosynthesize by capturing light and taking in carbon dioxide to make sugar, oxygen, and water. This monarch butterfly is also a system. It is a set of connected things like wings, the antenna, the legs, the circulatory system. And, like the tree, The flower is another system in this image. A system doesn't have to be a living thing. For example, look at the many parts of this system that work together to make a complex whole. Here is a model of the California ecosystem. It attempts to simplify complexity of the different influences on the ecosystem so that we can better understand it. You can see that it includes, among other things, ecological, human, political, and social inputs and outputs to this system. There are three types of systems that we will be considering in this course. It is important that you really understand the difference between these three types of systems. An open system exchanges both matter and energy with its surroundings. A closed system exchanges energy but not matter with its environment. exchanges neither matter nor energy with its environment. In topic 1.1, we discussed the inputs and outputs to an environmental value system. All open systems involve inputs that go into the system and that are processed. The processing events occur inside the system, resulting in some outputs. Inputs and outputs are referred to as transfers, while processing events are referred to as transformations. Transfers occur when energy or matter flows and changes location but does not change its state. In this image, matter or rain is being transferred from the cloud to Earth's surface. Rain is flowing from the cloud to Earth's surface. Rain is moving from the cloud to Earth's surface. The rain is in its same form or state at the top by the clouds as when it hits the ground. It is always liquid rain. Transformations occur when energy or matter flows and changes in state. A change can be chemical in nature, it can be a change of state, or a change in energy. In this image, hot tea is being thrown into minus 40 degrees Celsius air. The tea is flowing from the hot thermos into the air, and it is changing from liquid to solid. Thus, the tea is undergoing a transformation. It is experiencing a change in state from liquid to solid. You will be exposed to many models of systems, and will need to identify both transfers and transformations in and out of and within systems. For example, look at this simplified model of photosynthesis. The transfers or flows include flow of solar energy from the sun to the leaf, flow of carbon dioxide into the leaf, flow of water into the leaf, flow of oxygen out of the leaf, and flow of sugar into the organism that eats the leaf. Notice that in each of these examples there is only a movement of location. There is no change of state. The transformations include light energy changing into chemical energy or glucose and carbon dioxide and water changing into glucose. Stop the movie and make sure you understand how each of these events is either a transfer or a transformation. In this system of a plant as a system, we can also view the transfers as inputs and outputs. Energy and matter flow as inputs and outputs to a system. In this photosynthesis example, solar energy, carbon dioxide, and water are all inputs to the system when they enter the plant, while sugar and oxygen are outputs when they leave the plant. The processing event within the plant is photosynthesis. Can you see how the inputs are processed into some outputs? Sometimes energy or matter is also stored in an ecosystem as storages or stocks. In this example, the plant is considered a storage of carbon. All of the glucose that makes up the plant keeps carbon sunk in the plant. We also refer to this as a carbon sink because as long as the plant is alive, carbon is trapped within the plant. You need to become really comfortable with diagrams of systems. Let's take a look at what all systems have. They have storages or stores of matter or energy. These storages are represented by boxes. You can see the stores of the plant and of the consumer the organism that eats the plant. The plant and the consumers store matter, which could be carbon or nitrogen or phosphorus, depending on what aspect of the system you are attempting to diagram. Plants store chemical energy, which is transferred to the consumers in the process of eating or consumption. All systems have flows. which are represented by arrows. All systems have inputs, which are represented by arrows flowing in to the system. In this example, the plant system, there is an energy input of light and matter, inputs of water and carbon dioxide. All systems have outputs, represented by arrows flowing out of the system. In this example of the plant system, there is energy loss of heat and matter outputs of oxygen. If the plant is eaten by a consumer, there is a flow of chemical energy into the consumer from the plant, an output from the plant, and an input to the consumer. All systems have boundaries, which are represented by lines. you can see boundaries around both the plant and the consumer. All systems have processes which transfer or transform energy or matter from storage to storage. In this example, the process of respiration transforms energy to heat, and the process of diffusion transfers it to the atmosphere. The process of diffusion transfers water and carbon dioxide into the plant, while the process of diffusion transfers oxygen out of the plant. The process of photosynthesis transforms light energy to sugar and transfers it to the same storage of the plant. Stop the movie and study the key and the diagram. Also, compare the diagram to the picture. Make sure you understand the systems terminology illustrated on this slide. Are the systems of the plant and the consumer open, closed, or isolated systems? Both the plant and the consumer are open systems because both matter and energy are being exchanged. Matter of carbon dioxide and water. are going into the plant while oxygen is leaving the plant. Energy is also being exchanged with light coming in and heat going out. The consumer has chemical energy in the form of sugar going in and heat going out. Matter of oxygen goes in while carbon dioxide goes out. Of course, these are not all the flows happening in plants and consumers. It's just a representation of some flows and transformations. Most systems are open systems. All ecosystems. are open systems because they exchange matter and energy with their environment. Let's look at some of the flows in and out of this forest ecosystem. Water is lost through evaporation and transpiration from plants. Heat is exchanged with the surrounding environment across the boundaries of the forest. Plants fix energy from light entering the system. This fixing occurs during photosynthesis. Forest fires expose the topsoil, which may be removed by wind and rain. Mineral nutrients are leached out of the soil and transported in groundwater to streams and rivers. Nitrogen from the air is fixed by soil bacteria. Herbivores that live within the forest may graze in adjacent ecosystems, such as grassland. But when they return to the forest, they enrich the soil with feces. These are just some of the flows that occur in this ecosystem. Closed systems are rare in nature. But if we consider the globe, these cycles could be considered closed systems. On a global scale, the hydrological, carbon, and nitrogen cycles are all closed because they exchange only energy and not matter within their systems and the surroundings. The Earth is sort of a closed system in that primarily energy is exchanged between it and space. What small amount of matter enters and leaves Earth's atmosphere? Most examples of closed systems are artificial, like these sealed mesocosms. This one was last watered in 1972. They are sealed, so no matter can enter or leave the system. But Energy in the form of light enters the system, and energy in the form of heat leaves the system. Isolated systems do not exist naturally. Though it is possible to think of the entire universe as an isolated system, Biosphere 2 was built to test the viability of a closed ecological system to support and maintain humans in outer space. Thus, Biosphere 2 was built. with several biological biomes, living quarters for people, an agricultural area and workspace to study the interactions between humans, farming, technology, and the rest of nature. It was only inhabited twice, and both times the experiment ran into problems, including low amounts of food and oxygen. Carbon dioxide levels fluctuated widely. Plus, there were difficulties between the crew and in management of the project. The results of the biosphere illustrated how difficult it is to make a sustainable closed system. The complexities of the component ecosystems were not fully understood. The biosphere was an attempt to model Earth. A model is a simplified version of the real thing. Scientists use a variety of models to help understand how systems work. and to predict what happens if something changes. A model may take many forms. A model could be a physical model, like the globe, or a wind tunnel, or an aquarium, or a model of the solar system. Or a model can be a computer or software model, like this model of the Earth. There are mathematical models as well as data flow models. You will be using all kinds of models. in ESS. In 1979, James Lovelock proposed the Gaia hypothesis, the idea that Earth was a living organism. He named the theory after the Greek goddess Gaia, the primal mother Earth goddess, she who personifies Earth. Lovelock argued that the atmosphere is the organ that regulates Earth and connects all its parts. Lovelock based his principle of Earth as a model for a superorganism on these facts. Earth maintains a constant temperature despite changes in solar energy from the sun. The components of the atmosphere remain constant despite one of the components, oxygen, being a reactive gas. And the ocean's salinity remains constant despite rivers washing salts into the sea. In 2007, Lovelock's book, Revenge of Gaia, makes a strong case for Earth. being an older lady now, more than halfway through her existence of a planet, and not being able to bounce back from changes like she used to. You need to be able to construct a system diagram or a model from a given set of information. You also need to be able to evaluate the use of models as a tool in a given situation, like for climate change predictions. I will give you some very simple examples. this. Let's try a small example. Can you construct a diagram of inputs and outputs of a burning candle? Stop the movie and construct a system diagram with a box and arrows to represent this image. How did you do? Did you get the inputs and outputs and the main process of combustion? Now let's evaluate this model as a tool in this situation representing the inputs and outputs of a burning candle. The strengths of this model are that it provides a simplified diagram of the real candle. We could use it to make predictions. For example, if we blow air or more oxygen on the fire, will we see increased amounts of carbon dioxide, water, and heat? And if we do the experiment, we could use the model to show the results. Limitations of this model. Well, The real candle is much more complex than the model. It might not be totally accurate. For example, it doesn't show at all that there needs to be an initial source of heat to get the candle burning. Different people might interpret it in different ways. For example, someone might look at this model and conclude that a burning candle is good for the environment because it results in the production of water. And so a fossil fuel company... ... could use the model to then argue against the role of burning fossil fuels in climate change and hijack this model for political interests. So, generally speaking, strengths of models include they can allow scientists to predict, simplify complex systems. The inputs can be changed and outcomes examined without having to wait for real events. The results can be shown to scientists. and the public. Limitations of models are that they might not be totally accurate. Environmental factors are very complex, so models might be overly simple. Different models use slightly different data to calculate predictions. They rely on the expertise of people making them. Different people may interpret them in different ways. Vested interests might hijack them politically. Any model is only as good as the data that goes in, and these may be suspect. Different models may show different effects using the same data. So here is a brief summary of everything covered in this movie. A systems approach can help the study of complex environmental issues. Systems are open, closed, and isolated. You should be able to understand the difference between transfers and transformations, and recognize them. systems. Make sure you know the system terminology of storage, flows, inputs, outputs, boundaries, and processes. Understand that the use of models of systems simplifies interactions but may provide a more holistic view than reducing issues to single processes. There are many types of models, physical, computer, mathematical, data flow. There is the Gaia hypothesis. Understand how to construct system diagrams from given data and be able to evaluate models. This ends the movie for IBESS Topic 1.2, Systems and Models, under the main topic 1 of Foundations of Environmental Systems and Societies. The slides are created by me, Dr. Nina Markham. Images are courtesy of Creative Commons, unless otherwise indicated, with a citation under the image. If all images on a slide are from the same source, the source is simply cited at the bottom of the slide. Another resource for you is your IB ESS textbook, whether in hardback form or online, such as Cognity. Thank you for listening.

So let's start with a brief discussion of systems. A system is a set of connected things or interrelated parts working together to make a complex whole. You You might recall these images from topic 1.1.

In this image, there are several systems. One could be the tree. There are many parts of this tree that work together to allow it to photosynthesize by capturing light and taking in carbon dioxide to make sugar, oxygen, and water.

This monarch butterfly is also a system. It is a set of connected things like wings, the antenna, the legs, the circulatory system. And, like the tree, The flower is another system in this image.

A system doesn't have to be a living thing. For example, look at the many parts of this system that work together to make a complex whole. Here is a model of the California ecosystem.

It attempts to simplify complexity of the different influences on the ecosystem so that we can better understand it. You can see that it includes, among other things, ecological, human, political, and social inputs and outputs to this system. There are three types of systems that we will be considering in this course. It is important that you really understand the difference between these three types of systems.

An open system exchanges both matter and energy with its surroundings. A closed system exchanges energy but not matter with its environment. exchanges neither matter nor energy with its environment. In topic 1.1, we discussed the inputs and outputs to an environmental value system. All open systems involve inputs that go into the system and that are processed.

The processing events occur inside the system, resulting in some outputs. Inputs and outputs are referred to as transfers, while processing events are referred to as transformations. Transfers occur when energy or matter flows and changes location but does not change its state. In this image, matter or rain is being transferred from the cloud to Earth's surface. Rain is flowing from the cloud to Earth's surface.

Rain is moving from the cloud to Earth's surface. The rain is in its same form or state at the top by the clouds as when it hits the ground. It is always liquid rain.

Transformations occur when energy or matter flows and changes in state. A change can be chemical in nature, it can be a change of state, or a change in energy. In this image, hot tea is being thrown into minus 40 degrees Celsius air. The tea is flowing from the hot thermos into the air, and it is changing from liquid to solid. Thus, the tea is undergoing a transformation.

It is experiencing a change in state from liquid to solid. You will be exposed to many models of systems, and will need to identify both transfers and transformations in and out of and within systems. For example, look at this simplified model of photosynthesis. The transfers or flows include flow of solar energy from the sun to the leaf, flow of carbon dioxide into the leaf, flow of water into the leaf, flow of oxygen out of the leaf, and flow of sugar into the organism that eats the leaf.

Notice that in each of these examples there is only a movement of location. There is no change of state. The transformations include light energy changing into chemical energy or glucose and carbon dioxide and water changing into glucose.

Stop the movie and make sure you understand how each of these events is either a transfer or a transformation. In this system of a plant as a system, we can also view the transfers as inputs and outputs. Energy and matter flow as inputs and outputs to a system. In this photosynthesis example, solar energy, carbon dioxide, and water are all inputs to the system when they enter the plant, while sugar and oxygen are outputs when they leave the plant.

The processing event within the plant is photosynthesis. Can you see how the inputs are processed into some outputs? Sometimes energy or matter is also stored in an ecosystem as storages or stocks.

In this example, the plant is considered a storage of carbon. All of the glucose that makes up the plant keeps carbon sunk in the plant. We also refer to this as a carbon sink because as long as the plant is alive, carbon is trapped within the plant.

You need to become really comfortable with diagrams of systems. Let's take a look at what all systems have. They have storages or stores of matter or energy. These storages are represented by boxes.

You can see the stores of the plant and of the consumer the organism that eats the plant. The plant and the consumers store matter, which could be carbon or nitrogen or phosphorus, depending on what aspect of the system you are attempting to diagram. Plants store chemical energy, which is transferred to the consumers in the process of eating or consumption.

All systems have flows. which are represented by arrows. All systems have inputs, which are represented by arrows flowing in to the system.

In this example, the plant system, there is an energy input of light and matter, inputs of water and carbon dioxide. All systems have outputs, represented by arrows flowing out of the system. In this example of the plant system, there is energy loss of heat and matter outputs of oxygen.

If the plant is eaten by a consumer, there is a flow of chemical energy into the consumer from the plant, an output from the plant, and an input to the consumer. All systems have boundaries, which are represented by lines. you can see boundaries around both the plant and the consumer.

All systems have processes which transfer or transform energy or matter from storage to storage. In this example, the process of respiration transforms energy to heat, and the process of diffusion transfers it to the atmosphere. The process of diffusion transfers water and carbon dioxide into the plant, while the process of diffusion transfers oxygen out of the plant.

The process of photosynthesis transforms light energy to sugar and transfers it to the same storage of the plant. Stop the movie and study the key and the diagram. Also, compare the diagram to the picture.

Make sure you understand the systems terminology illustrated on this slide. Are the systems of the plant and the consumer open, closed, or isolated systems? Both the plant and the consumer are open systems because both matter and energy are being exchanged.

Matter of carbon dioxide and water. are going into the plant while oxygen is leaving the plant. Energy is also being exchanged with light coming in and heat going out. The consumer has chemical energy in the form of sugar going in and heat going out.

Matter of oxygen goes in while carbon dioxide goes out. Of course, these are not all the flows happening in plants and consumers. It's just a representation of some flows and transformations. Most systems are open systems. All ecosystems.

are open systems because they exchange matter and energy with their environment. Let's look at some of the flows in and out of this forest ecosystem. Water is lost through evaporation and transpiration from plants.

Heat is exchanged with the surrounding environment across the boundaries of the forest. Plants fix energy from light entering the system. This fixing occurs during photosynthesis. Forest fires expose the topsoil, which may be removed by wind and rain.

Mineral nutrients are leached out of the soil and transported in groundwater to streams and rivers. Nitrogen from the air is fixed by soil bacteria. Herbivores that live within the forest may graze in adjacent ecosystems, such as grassland.

But when they return to the forest, they enrich the soil with feces. These are just some of the flows that occur in this ecosystem. Closed systems are rare in nature.

But if we consider the globe, these cycles could be considered closed systems. On a global scale, the hydrological, carbon, and nitrogen cycles are all closed because they exchange only energy and not matter within their systems and the surroundings. The Earth is sort of a closed system in that primarily energy is exchanged between it and space. What small amount of matter enters and leaves Earth's atmosphere? Most examples of closed systems are artificial, like these sealed mesocosms.

This one was last watered in 1972. They are sealed, so no matter can enter or leave the system. But Energy in the form of light enters the system, and energy in the form of heat leaves the system. Isolated systems do not exist naturally. Though it is possible to think of the entire universe as an isolated system, Biosphere 2 was built to test the viability of a closed ecological system to support and maintain humans in outer space.

Thus, Biosphere 2 was built. with several biological biomes, living quarters for people, an agricultural area and workspace to study the interactions between humans, farming, technology, and the rest of nature. It was only inhabited twice, and both times the experiment ran into problems, including low amounts of food and oxygen.

Carbon dioxide levels fluctuated widely. Plus, there were difficulties between the crew and in management of the project. The results of the biosphere illustrated how difficult it is to make a sustainable closed system.

The complexities of the component ecosystems were not fully understood. The biosphere was an attempt to model Earth. A model is a simplified version of the real thing. Scientists use a variety of models to help understand how systems work.

and to predict what happens if something changes. A model may take many forms. A model could be a physical model, like the globe, or a wind tunnel, or an aquarium, or a model of the solar system.

Or a model can be a computer or software model, like this model of the Earth. There are mathematical models as well as data flow models. You will be using all kinds of models.

in ESS. In 1979, James Lovelock proposed the Gaia hypothesis, the idea that Earth was a living organism. He named the theory after the Greek goddess Gaia, the primal mother Earth goddess, she who personifies Earth. Lovelock argued that the atmosphere is the organ that regulates Earth and connects all its parts. Lovelock based his principle of Earth as a model for a superorganism on these facts.

Earth maintains a constant temperature despite changes in solar energy from the sun. The components of the atmosphere remain constant despite one of the components, oxygen, being a reactive gas. And the ocean's salinity remains constant despite rivers washing salts into the sea. In 2007, Lovelock's book, Revenge of Gaia, makes a strong case for Earth. being an older lady now, more than halfway through her existence of a planet, and not being able to bounce back from changes like she used to.

You need to be able to construct a system diagram or a model from a given set of information. You also need to be able to evaluate the use of models as a tool in a given situation, like for climate change predictions. I will give you some very simple examples. this.

Let's try a small example. Can you construct a diagram of inputs and outputs of a burning candle? Stop the movie and construct a system diagram with a box and arrows to represent this image.

How did you do? Did you get the inputs and outputs and the main process of combustion? Now let's evaluate this model as a tool in this situation representing the inputs and outputs of a burning candle.

The strengths of this model are that it provides a simplified diagram of the real candle. We could use it to make predictions. For example, if we blow air or more oxygen on the fire, will we see increased amounts of carbon dioxide, water, and heat?

And if we do the experiment, we could use the model to show the results. Limitations of this model. Well, The real candle is much more complex than the model. It might not be totally accurate.

For example, it doesn't show at all that there needs to be an initial source of heat to get the candle burning. Different people might interpret it in different ways. For example, someone might look at this model and conclude that a burning candle is good for the environment because it results in the production of water. And so a fossil fuel company... ...

could use the model to then argue against the role of burning fossil fuels in climate change and hijack this model for political interests. So, generally speaking, strengths of models include they can allow scientists to predict, simplify complex systems. The inputs can be changed and outcomes examined without having to wait for real events.

The results can be shown to scientists. and the public. Limitations of models are that they might not be totally accurate. Environmental factors are very complex, so models might be overly simple. Different models use slightly different data to calculate predictions.

They rely on the expertise of people making them. Different people may interpret them in different ways. Vested interests might hijack them politically. Any model is only as good as the data that goes in, and these may be suspect.

Different models may show different effects using the same data. So here is a brief summary of everything covered in this movie. A systems approach can help the study of complex environmental issues.

Systems are open, closed, and isolated. You should be able to understand the difference between transfers and transformations, and recognize them. systems. Make sure you know the system terminology of storage, flows, inputs, outputs, boundaries, and processes. Understand that the use of models of systems simplifies interactions but may provide a more holistic view than reducing issues to single processes.

There are many types of models, physical, computer, mathematical, data flow. There is the Gaia hypothesis. Understand how to construct system diagrams from given data and be able to evaluate models. This ends the movie for IBESS Topic 1.2, Systems and Models, under the main topic 1 of Foundations of Environmental Systems and Societies. The slides are created by me, Dr. Nina Markham.

Images are courtesy of Creative Commons, unless otherwise indicated, with a citation under the image. If all images on a slide are from the same source, the source is simply cited at the bottom of the slide. Another resource for you is your IB ESS textbook, whether in hardback form or online, such as Cognity. Thank you for listening.

Transcript for:Understanding Systems and Models in IBESS

Transcript for:
Understanding Systems and Models in IBESS