Environmental Systems
Summary
TLDRThis Environmental Science video delves into the concept of environmental systems, emphasizing the importance of understanding inputs and outputs for effective management. It highlights the Aral Sea's transformation into a desert due to inefficient irrigation, illustrating the consequences of poor system management. The video explains the closed nature of matter on Earth and the open system of energy, introducing the laws of thermodynamics and their impact on resource availability and energy conversion. It also touches on the significance of atoms, their organization in the periodic table, and their role in forming stable molecules. The script concludes by discussing systems analysis, steady states, and the role of feedback loops in maintaining balance in natural systems.
Takeaways
- π Understanding systems is crucial for addressing environmental challenges, such as the transformation of the Aral Sea into a desert due to inefficient irrigation practices.
- π§ The Earth is a system with inputs and outputs, and managing these effectively is key to environmental sustainability.
- π Matter on Earth is conserved; it is a closed system, meaning we cannot create or destroy matter, only transform it.
- βοΈ Energy, on the other hand, is an open system where we receive energy from the sun and lose it as heat, highlighting the importance of energy conservation and efficiency.
- π¬ Systems analysis is essential for maintaining steady states or equilibrium in environmental systems, using feedback loops to regulate inputs and outputs.
- π The first law of thermodynamics states that energy cannot be created or destroyed, only converted from one form to another.
- π The second law of thermodynamics emphasizes the loss of useful energy during conversion, leading to an increase in entropy and the generation of heat.
- πΏ The periodic table organizes the finite atoms on Earth, with elements like carbon being fundamental to building complex molecules through covalent bonds.
- 𧬠Humans, like all living organisms, are composed primarily of water, with oxygen being the most abundant element by mass.
- π Water's polarity affects its behavior, which is important in environmental systems, including understanding pH and the role of buffers.
- π‘ The study of energy and its quantification, such as in the work of James Joule, is fundamental to understanding the capacity to do work and the flow of energy in systems.
Q & A
What is the main topic of the Environmental Science video 2?
-The main topic of the video is understanding environmental systems, including what a system is, how it works, and how to manage inputs and outputs to tackle environmental problems.
Why is the Aral Sea a good example to discuss in the context of environmental systems?
-The Aral Sea serves as a good example because it used to be the fourth largest lake on the planet but became a desert due to inefficient irrigation practices, illustrating the consequences of poor system management.
What were the consequences of the Soviet Union's irrigation practices on the Aral Sea?
-The consequences included the death of fish, the collapse of the fishing industry, and an economic downturn, all resulting from the mismanagement of the water resources and the system's inputs and outputs.
How does the Earth's system differ from the system of matter and energy in terms of being open or closed?
-The Earth's system of matter is a closed system with a finite amount of atoms that are conserved over time. In contrast, the system of energy is open, receiving energy from the sun and losing it as heat.
What are the two main components of a system that we need to focus on according to the video?
-The two main components to focus on are matter and energy. Matter is what everything is made of, while energy is the ability to do work.
What is the significance of the conservation of matter on our planet?
-The conservation of matter means that the amount of matter on our planet is finite and does not increase or decrease over time. This has implications for resource management, as we cannot create new minerals or elements.
What is the first law of thermodynamics, and how does it relate to energy?
-The first law of thermodynamics, also known as the law of conservation of energy, states that energy cannot be created or destroyed, only converted from one form to another.
What does the second law of thermodynamics tell us about energy conversion?
-The second law of thermodynamics indicates that with every energy conversion, some of the useful energy is lost as heat, which is not usable for further work on our planet.
How does systems analysis help in understanding the state of a system?
-Systems analysis helps by examining the inputs and outputs of a system to determine if it is at a steady state or equilibrium. It also helps in identifying feedback loops that can either maintain or disrupt this steady state.
What is a negative feedback loop, and how does it help maintain a steady state in a system?
-A negative feedback loop is a process within a system that corrects changes and helps maintain a steady state by counteracting deviations. For example, as a lake's water level rises, increased evaporation and drainage work to lower it back to the steady state.
What role do positive feedback loops play in the Earth's climate system?
-Positive feedback loops in the Earth's climate system amplify changes rather than counteract them. For instance, increased evaporation due to warming can lead to more greenhouse gases, which in turn causes further warming.
Why is the understanding of atoms and their organization on the periodic table important in environmental science?
-Understanding atoms and their organization on the periodic table is crucial because it helps us comprehend the composition of various environmental components, such as humans, water, rocks, and the atmosphere, and how they interact within the Earth's system.
What is the significance of oxygen in the composition of living organisms, water, and rocks?
-Oxygen is significant because it is the most abundant element in living organisms, water (H2O), and many rocks, such as silicates. It plays a central role in biological processes, the water cycle, and geological formations.
How does the concept of a steady state relate to the management of environmental systems?
-A steady state in environmental systems indicates a balance between inputs and outputs, which is essential for sustainability. Managing a system towards a steady state helps maintain ecological balance and prevent degradation or depletion of resources.
Outlines
πΏ Environmental Systems and Their Management
This paragraph introduces the concept of environmental systems, emphasizing the importance of understanding systems to address complex environmental issues. The Aral Sea's transformation into a desert due to inefficient irrigation practices by the Soviet Union serves as a case study. It highlights the necessity of managing inputs and outputs within a system. The Earth is described as a system with finite matter and a continuous flow of energy from the sun, introducing the principles of conservation of matter and energy, as well as the laws of thermodynamics. Systems analysis is presented as a tool for understanding system dynamics, including steady states and feedback loops.
π₯ Energy Quantification and Thermodynamics
The second paragraph delves into the quantification of energy, crediting James Joule for establishing the measurement of energy in joules. It explains the concept of watts as joules per second, illustrating the relationship between energy, work, and time. The laws of thermodynamics are discussed, focusing on the conservation of energy and the inevitable loss of usable energy at each stage of conversion, leading to heat. Systems analysis is applied to the Earth's climate, using the metaphor of a bathtub with holes to explain steady states and the role of feedback loops in maintaining them. The paragraph concludes with examples of both negative and positive feedback loops in the Earth's climate system, such as the melting of ice and the effect of water vapor as a greenhouse gas.
Mindmap
Keywords
π‘Environmental Systems
π‘Aral Sea
π‘Irrigation
π‘Economic Collapse
π‘Inputs and Outputs
π‘Matter
π‘Energy
π‘Thermodynamics
π‘Feedback Loops
π‘Steady State
π‘Atoms
π‘Polar Molecules
π‘pH and Buffers
π‘Biological Molecules
Highlights
Understanding environmental systems is crucial for tackling major environmental problems.
The Aral Sea example illustrates the consequences of poor environmental system management.
The Earth is a system with inputs and outputs that need to be managed for sustainability.
Matter on Earth is conserved, making it a closed system with finite resources.
Energy on Earth is an open system, receiving energy from the sun and losing it as heat.
The conservation of matter has significant implications for resource management.
The first law of thermodynamics states that energy cannot be created nor destroyed.
The second law of thermodynamics addresses the loss of useful energy during conversion.
Systems analysis involves understanding the balance of inputs and outputs to maintain steady states.
Negative feedback loops help maintain steady states in systems, such as lake levels.
Positive feedback loops can destabilize systems, as seen in global warming scenarios.
The periodic table organizes atoms, which differ in reactivity based on their electron configuration.
Carbon's unique electron configuration allows it to form complex molecules, essential for life.
The human body's composition is predominantly oxygen and hydrogen, due to water content.
Seawater's composition is similar to the human body, with oxygen and hydrogen being the majority.
Rocks are primarily composed of oxygen, with significant amounts of silicon, aluminum, and iron.
The atmosphere is mostly nitrogen and oxygen, with trace elements playing various roles.
Water's polar nature affects its behavior and is fundamental to understanding environmental systems.
pH and buffers are crucial concepts for understanding environmental chemistry.
Biological molecules, built from atoms, are the basis of life and are integral to environmental systems.
James Joule's experiments quantified energy, leading to the unit of energy measurement, the joule.
Transcripts
Hi. Itβs Mr. Andersen and this Environmental Science video 2. It is on environmental systems.
Understanding what a system is and how it works can allow us to tackle really hard,
some of the worst environmental problems that we have ever had. A good example would be
the Aral Sea. And so it sits on the border of Kazakhstan and Uzbekistan. And it used
to be the fourth largest lake on the planet. And so the Soviet Union was irrigating off
the Aral Sea to grow cotton and rice. And it was not super efficient irrigation. And
so if you watch what happened to the Aral Sea from 1989 until to 2014, it essentially
became a desert. And so we just see the South Aral Sea on the western margin. So the fish
all died. The fishing died. And so we had economic collapse. And this was a problem
with the system. We were not managing the inputs and the outputs. So the earth at the
largest level is a system. It is separated from its surroundings. And understanding the
inputs and the outputs allows us to manage a system. And so the big things we are looking
at are the matter and then the energy. The matter remember is what we are made of. It
is the atoms that make us and the rock and the water. And the energy is the ability to
do work. Now if we look at the matter on our planet, it is actually a closed system. The
amount of matter we have on our planet is conserved. We do not get new matter from space
so we are stuck with the atoms that we have. It is conserved over time. If we look at the
energy however, it is more of an open system. We continue to get energy coming from the
sun and we lose that energy as heat. And so the thing about matter you should understand
is that it is conserved. And this has huge ramifications. If we are looking, for example,
for minerals. You can not just grow minerals. The amount of minerals we have on our planet
are finite and we have to go find those minerals. If we are looking at energy, understanding
the laws of thermodynamics. The first law is essentially the conservation of energy.
Energy can neither be created nor destroyed. But the second law is also important. And
that deals with the amount of useful energy. Every time we have an interaction when we
are converting energy, we are losing some of that useful energy. And so understanding
how a system works is done through systems analysis. If it does not change we say that
system is at steady state or at equilibrium. And we can move it towards steady state using
a negative feedback loop or away using a positive feedback loop. So big picture, a system is
simply separated from its surroundings using a boundary. And we would call this a closed
system, like the matter we have on our planet is a closed system. We do not get new matter.
We do not lose matter, generally to space. If we look at an open system like energy,
then there is flow from the surroundings into the system and vice versa. And so matter,
on our planet, is made up of a finite amount of atoms. And atoms are organized on the periodic
table. If we look at the simplest atom, hydrogen is going to have 1 proton and 1 electron.
It is highly reactive. Everything else in this column is also reactive because it has
a single valence electron. If we were to go to helium, helium could have 2 electrons in
this first shell. And since it has two it is incredibly stable. So is everything else
right here. If we were to grab an important biological atom, like carbon, it is going
to have 4 valence electrons. Two on the inside, four on the outside. So it is kind of the
lego block. We can build so many complex molecules off of that. And these are all through covalent
bonds. And so if we look at methane for example, methane is 1 carbon, 4 hydrogens. We are sharing
those electrons around the outside, so we have an incredibly stable molecule. And so
the atoms we have on the planet are going to differ depending on where we are. So if
we are looking at humans, think about this for a second, what are most of the atoms in
a human going to be? We letβs break it down by percent composition. We are mostly made
of water. And so it is mostly going to be oxygen and hydrogen. We are built out of carbon,
hydrogen is so low because it has such a small mass. We are also going to have nitrogen,
calcium, phosphorous. But in general we are going to be made by mass of oxygen. If we
were to look at the water, so the sea water right here, what is most of that? We could
break it up this way. It is mostly going to be oxygen as well. It is mostly made of water.
We are also going to have salts, like sodium and chloride. But it is mostly made of oxygen
and hydrogen. If we look at the rock, what is the rock mostly made up of? Oxygen. Now
there is going to be silicon. We are going to have aluminum and iron. But in general,
it is oxygen. And if we look at the atmosphere, that is going to mostly be nitrogen, but we
are also going to have a large amount of oxygen there as well, and other trace elements. And
so the oxygen in the atmosphere can eventually become oxygen in the rock. It could be oxygen
in the water. It can be oxygen in you. It has to be recycled because we are not creating
new atoms on our planet. Other important parts of this course will be understanding how water
is polar and that affects its behavior. Understanding pH and buffers. And then finally biological
molecules. So if you feel like you do not have a good enough background in these areas,
I have put videos down below and you could surely watch those. The next thing we should
deal with is energy. Energy was first quantified by James Joule using this apparatus. It has
a weight that would fall. It would spin paddles inside water and so you could measure changes
in the temperature using a thermometer. We were able to quantify energy, which is the
ability to do work. We measure that, a nod to James Joule as a joule. Now when you talk
about energy, generally you are going to hear things like watts. What is a watt? A watt
is going to be a joule per second. So that is time. So if you are talking about kilowatts
we are measuring the amount of energy that is being used over a given period of time.
Understanding the laws of thermodynamics is incredibly important. So if a car moves from
here to here it is converting energy. We are not creating energy we are converting it from
one form to another. So where is the energy before it was in that motion of the car? It
was in the gasoline. Before then it was in crude oil. Before then it was in ancient rain
forest. Before then it was given off by sunlight and used by that rainforest through photosynthesis.
But we are not creating new energy. We cannot create nor destroy energy. That is the first
law of thermodynamics. The second law deals more with systems. So we are going to have
inputs going into the system of the car. And then we are going to have outputs. And if
we look at the amount of energy that goes into the car, we could think of that gasoline,
the energy in the gasoline itself, we are using some that energy for the kinetic motion
of the car. But we are also losing some of that energy in friction and heat and sound.
And so what the second law of thermodynamics talks to is that at each interaction, at each
point along that pathway we are losing some of that useful energy. It is eventually becoming
heat which is non usable on our planet. And so understanding this balance is the area
of systems analysis. And this model works well. Think of it as a bathtub that has holes
in it. You have input. Then you have output. And if the amount of input matches the amount
of output then we are at what is called steady state. If we could see that. But what happens
if we have an increase inputs or an increase in outputs, what we can do is we can lose
that steady state. And maintaining that is feedback loops. So if we look at a real system
on our planet, a Swiss lake we would find that the level of the lake is going to be
steady state. And in nature we find that almost all systems in nature are going to be steady
state. So they are going to stay at the same level. Well how do they do that? They do that
through feedback loops. And so if you think about it, as we melt the snow. As we increase
the amount of water in the lake, the level goes up. We might have more drainage, and
that is going to keep the level the same. What else might happen? Since the lake is
really large we are going to have more evaporation off that surface and the level of the lake
is going to go down. Now we have a smaller surface area, there is less evaporation. Now
the level of the lake is going to go up. So that is a negative feedback loop. You could
look at that at the level of the earth system as well. And so the earth is being heated.
We are increasing green house gases. We are increasing the temperature on our planet.
And so there is a negative feedback loop that takes care of that. As we heat up the planet
there is more heat on the planet. What happens, we lose more of that heat to space. And so
that is a negative feedback loop. The problem is that we also have positive feedback loops
working on the planet right now. So an example, if we heat up the ocean, what happens? We
are getting evaporation off the ocean. That creates water vapor and water vapor is an
incredible greenhouse gas. What does that do? It heats up the earth which creates more
evaporation of water and more global warming. Another example, we could look at this white
area up here. So if we have a lot of ice that has a high albedo, it reflects a lot of the
light back into space. What happens as we start to melt that ice, then there is less
albedo. We are absorbing more of that heat and so we are increasing the temperature.
And so did you learn the following? I would pause the video right now and try to fill
in the blanks. But I will show you what it all means. And so we can think of remember
the earth as a system. It has inputs and outputs. We do systems analysis to measure that steady
state. Remember it could be negative or positive feedback loop. Remember the energy is an open
system versus a closed system of the matters. So the matter is conserved. And that whole
study is called thermodynamics. So hopefully you learned that. And I hope that was helpful.
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