Unit 6: AP Environmental Science Faculty Lecture with Lecturer Erica Tietjen

Summary

Erica Tietjen, a biology and environmental science lecturer, guides us through the intricate web of energy transformations in ecological systems as covered in Unit 6 of AP Environmental Science. The video delves into the concepts of energy forms, thermodynamics, and their implications on biological and ecological processes, using relatable analogies such as cheeseburgers and fungi. Tietjen emphasizes the interconnections between biological processes like decomposition and photosynthesis, and the resulting energy transformations that impact everything from climate change to agriculture, thereby illustrating the critical links between human actions and the planet's health.

Highlights

• Erica Tietjen introduces her lecture by connecting energy to simple everyday objects like cheeseburgers. 🍔
• The First and Second Laws of Thermodynamics are foundational to understanding energy transformations. 📜
• Cellular respiration and photosynthesis are linked processes critical to energy balance and lifecycle on Earth. 🔄
• Global climate change affects decomposition rates, impacting carbon cycles worldwide. 🌿
• Methane’s impact as a greenhouse gas is profound, highlighted by its heat retention properties. 🌪️
• Solar power, now the cheapest electricity source, exemplifies potential future shifts in global energy reliance. ☀️

Key Takeaways

• Energy is the ability to do work, vital across all systems, from nuclear plants to single-cell organisms. ⚡
• The laws of thermodynamics play central roles: energy isn't created or destroyed, and entropy always increases. 📉
• Photosynthesis and decomposition are reciprocal processes that fuel life on Earth and its ecosystems. 🌱
• Fossil fuels connect deeply with agriculture, evidencing the intertwined nature of our energy systems. 🌍
• Methane is a significant greenhouse gas, with both natural and anthropogenic sources impacting climate. 🌡️

Overview

In this fascinating lecture, Erica Tietjen explores the interwoven tapestry of energy transformations essential to life on Earth. Energy, defined as the ability to do work, is fundamental in systems ranging from tiny microbes to vast ecosystems. Tietjen connects these concepts to real-world examples like cheeseburgers, illustrating the everyday relevance of these scientific principles.

Tietjen deeply dives into the concepts of thermodynamics, emphasizing the laws of energy conservation and entropy. Through processes like photosynthesis and decomposition, Tietjen explains how energy transformations underpin ecological systems, driving everything from climate dynamics to basic biological functions.

Highlighting connections between energy use, human activity, and environmental health, Tietjen stresses the importance of transitioning toward sustainable practices. She discusses the role of fossil fuels in agriculture and methane as a greenhouse gas, bridging these complex topics to comprehensible insights for a future-focused environmental understanding.

Chapters

• 00:00 - 01:30: Introduction & Lecturer Background In this introductory chapter, lecturer Erica Tan welcomes the audience to the AP daily lecture on 'Energy Resources and Consumption,' focusing on topics like the energy of fungi, fossil fuels, and cheeseburgers. She provides a brief background about herself, mentioning that she is a lecturer in biology and environmental science at Nevada State.
• 01:30 - 04:00: Defining Energy and Its Forms The chapter titled 'Defining Energy and Its Forms' begins with an introduction to the instructor's background, highlighting their experience in aquatic ecology and current doctoral studies in science education. The instructor has been teaching college since 2005 and joined Nevada State in the previous year. They specialize in leaf litter decomposition within freshwater environments and are interested in the effects of invasive species. Their research continues at the University of Nevada, Las Vegas, focusing on aspects of science education. This background sets the stage for exploring the various definitions and forms of energy in the subsequent sections of the chapter.
• 04:00 - 07:00: Energy in Biological Systems This chapter, titled 'Energy in Biological Systems,' is part of an undergraduate course in biology and environmental science. It emphasizes the importance of representational models such as images, graphs, and pictures for understanding complex concepts. The speaker acknowledges their lack of artistic skills but stresses the value of connecting visual representations to mental models, aiding in comprehension. The chapter sets the stage to explore various topics, focusing primarily on energy in biological contexts.
• 07:00 - 09:30: First and Second Laws of Thermodynamics This chapter begins by defining energy and discussing various forms and components of energy. The main focus is then on the relationship between energy and biological processes, and how these processes connect to broader energy resources and ultimately impact us. The classic definition of energy is also introduced.
• 09:30 - 12:00: Energy Transformations and Fossil Fuels This chapter delves into the concept of energy transformations, highlighting the fundamental definition of energy as the capacity to do work across various systems. These systems could range from individual human bodies to large-scale nuclear power plants. The discussion includes different types of energy, such as chemical, mechanical, and radiant or electromagnetic energy, emphasizing the importance of understanding energy transformations across different scales and contexts.
• 12:00 - 15:00: Pause and Reflect: Energy Origins The chapter titled 'Pause and Reflect: Energy Origins' delves into the various forms of energy such as electrical, nuclear, atomic, and thermal energy. It highlights the significance of energy in biological systems, particularly focusing on how energy can be understood through the movement of electrons. This understanding includes the transformation of materials, breaking and forming of chemical bonds, and the central role of electrons in these processes. The chapter emphasizes a biological perspective on energy, rather than the physical or chemical viewpoints.
• 15:00 - 21:00: Cheeseburger Model: Fungi and Decomposition The chapter explains the role of ATP as the primary energy currency in biological systems. It highlights the importance of ATP in anabolic reactions, which involve building bonds and consequently consume energy stored in ATP molecules. Conversely, catabolic reactions, which break bonds, release energy and heat and are portrayed as purposeful processes that harness energy for various biological functions.
• 21:00 - 27:00: Aquatic Fungi and Decomposition The chapter titled 'Aquatic Fungi and Decomposition' discusses the fundamental role of thermodynamic laws in the ecological systems on Earth, specifically focusing on the laws of conservation of energy. This principle states that energy is neither created nor destroyed but only changes forms. The chapter sets the stage for exploring how these laws apply to aquatic fungi and their roles in decomposition processes.
• 27:00 - 29:00: Pause and Reflect: Decomposition Processes The chapter titled 'Pause and Reflect: Decomposition Processes' discusses the concepts of the first and second laws of thermodynamics. It emphasizes the transformation processes inherent in these laws, particularly focusing on the second law's assertion about the increase of entropy, defined as disorder over time. The chapter explains that as transformations occur, energy degrades, impacting the matter on Earth.
• 29:00 - 35:00: Photosynthesis and Plant Energy Transformation The chapter discusses the interconnectedness of matter and energy, particularly focusing on their transformations. It highlights the importance of understanding these concepts at a macro level to appreciate their role in life on Earth, especially underlining how energy is used and produced during these processes.
• 35:00 - 36:30: Pause and Reflect: Importance of Photosynthesis The chapter titled 'Pause and Reflect: Importance of Photosynthesis' emphasizes the critical role of photosynthesis and energy transformations in supporting life on Earth. Everything we utilize, consume, or discard represents a form of energy transformation that ultimately traces back to natural processes, highlighting how interconnected and reliant we are on our planet's natural capital.
• 36:30 - 47:00: Beef Production and Energy Use The chapter begins by discussing the biological origins of various energy sources, highlighting fossil fuels as a key example. It explains how fossil fuels, which are derived from ancient organic matter, play a significant role in everyday energy use. The process of transforming fossil fuels into usable energy involves numerous energy transformations. The chapter emphasizes the ubiquitous nature of fossil fuels and their integral role in modern energy systems.
• 47:00 - 52:00: Methane and Greenhouse Gases The chapter titled 'Methane and Greenhouse Gases' focuses on two fundamental questions: how energy is used in the transformation process, and how energy is produced. Throughout the discussion, opportunities are provided to pause and reflect on these topics.
• 52:00 - 55:30: Summary of Energy Transformations The chapter discusses energy transformations with emphasis on 'brain light bulb moments,' encouraging reflective thinking. It prompts readers to select an object from their surroundings, consider its origins and materials, and reflect on the energy transformations involved in its creation and use. This exercise is designed to help understand the practical implications of energy transformations in everyday objects.
• 55:30 - 57:30: Pause and Reflect: Connections to Other Issues The chapter titled 'Pause and Reflect: Connections to Other Issues' encourages readers to consider the energy used in the production and transportation of items they encounter. It prompts readers to think about the living processes involved in getting an object to its current location. Additionally, the chapter challenges readers to find anything that has not undergone any transformations, highlighting the pervasive nature of change and transformation in the world.
• 57:30 - 59:30: Conclusion In the conclusion chapter, the speaker reflects on the environmental impact of fossil fuels, particularly in relation to the energy required to transport materials. They use the example of a veggie burger (though they are not vegetarian) to illustrate their point. This emphasizes the importance of considering the energy footprint of everyday items.

Unit 6: AP Environmental Science Faculty Lecture with Lecturer Erica Tietjen Transcription

• 00:00 - 00:30 well hello um and Welcome to our uh AP daily lecture uh conversation uh from unit 6 uh energy resources and consumption uh my name is Erica tan and I'll be talking to you about energy of fungi fossil fuels and cheeseburgers today so just a little bit about who I am uh to get started this morning so I am a lecturer of biology and environmental science uh Nevada state
• 00:30 - 01:00 College in Henderson Nevada I've been teaching college since 2005 I've been here at Nevada state since uh last year um I'm also by my background in training an aquatic ecologist um I'm interested in leaf litter decomposition in freshwat environments streams and wetlands and also the impact of invasive species um and I am also currently a a doctoral student uh in Science Education at the University of Nevada Las Vegas that's UNLV and some of my research interests
• 01:00 - 01:30 are in um undergraduate biology and environmental science student understanding of and construction of representational models like images graphs and pictures so I'm not an artist by any stretch of the imagination but I certainly uh recognize the value and importance of being able to connect things on paper to being able to connect things into your brain and make those important mental models so some of the things we're going to talk about today uh primarily focused
• 01:30 - 02:00 around energy so we'll talk a little bit uh and Define what energy is take a look at some of the uh forms and components of energy and then we'll get right into thinking about how energy relates to biological processes and how these processes connect to um our energy resources and then ultimately to us so just to start out by defining uh the the classic definition of what
• 02:00 - 02:30 energy is um and that is the ability or capacity to do work within a system and if you think about what system means here it can mean a lot of things it can mean you individually as a human system we could be thinking about an ecosystem we could be thinking about a nuclear power plant so we have to consider all scales when we think about that um some examples of types of energy would be things like chemical energy mechanical energy uh radiant or electromagnetic
• 02:30 - 03:00 energy electrical nuclear or Atomic and and also thermal energy but when we get down to thinking about biological systems um that energy represented by electrons so we can think about the movement of electrons as uh materials are transformed um as chemical bonds are broken and as chemical bonds are formed and in biology when we start thinking about energy we tend to talk about
• 03:00 - 03:30 ATP as our energy currency uh there are other molecules that can carry electrons um but when we talk about energy being used as ATP in anabolic reactions that's the the um reactions that um build bonds and then the energy and heat that are made as a consequence of catabolic reactions that break bonds to purposefully get energy um and also heat
• 03:30 - 04:00 though as a consequence of that process and regardless of what kind of system we're thinking and talking about on Earth those systems are Guided by the laws of thermodynamics and so the two that matter the most to our conversation are the first and second laws and the first is the law of conservation of energy and this law states uh energy isn't created or destroyed it only changes forms so we're already thinking
• 04:00 - 04:30 about Transformations built into that first law the second law states um and talks about uh Disorder so talks about the the increase of entropy as disorder through time and with uh Transformations so the second law also considers the degradation of energy as Transformations occur and if we take this to the next step and think about what this means for matter on Earth and
• 04:30 - 05:00 matter as We Know It And how that relates to energy really these two laws tie together both of those things so we have the use and change of matter that is then tied with the energy that's used as well as the energy that's made during those Transformations and so if we really kind of take this up to to the biggest scale we have and we think about life on Earth and how important these energy
• 05:00 - 05:30 transformations are to life on Earth all the things that we have matter of of All Sorts materials of all kinds we get from our Earth's uh what we would describe as natural Capital so pretty much everything we make everything we use everything we consume the waste products that come out of those consumptions anything we throw away all represent energy transformations and when you get down to It ultimately those transformations can tie themselves back
• 05:30 - 06:00 to biological Origins so if you think just for a moment about some examples let's talk about fossil fuels for a minute um a lot of the things that we use on a regular basis um include fossil fuels in those Transformations and even the the mere Act of making fossil fuels and using fossil fuels there are a lot of energy transformations associated with that um so really for anything we
• 06:00 - 06:30 can think of we could consider two fundamental questions we could think about number one how is energy used um in that transformation of energy and then secondly how is energy made so what we'll do periodically through our conversation here today is uh give you an opportunity to pause and reflect on some questions as they relate to the topics we're discussing and so this is one of those pause and reflect
• 06:30 - 07:00 moments for you so when you see the little brain light bulb this will be the moment where we'll take a look together and uh you'll have a chance to think so what I'd like for you to do at this moment wherever you are um that's at home or outside um wherever that happens to be look around your space choose any object you like um focus on that for a minute think about its Origins and also the materials that it uses so where it came from what it uses and then ask
• 07:00 - 07:30 yourself these questions so what energy was used to get it to you to get it to where it is and then secondly what energy was made by the living processes that are built in that got it there so we'll talk more about those living processes um and my bonus challenge to you is to find anything not just the object that you're thinking about but anything that contains no transformations of any kind so this also
• 07:30 - 08:00 would include fossil fuels and things of of an energy requirement that it would take to get that material to you so pause for a moment in the video and we'll be back in a minute so I looked around my room space and it's lunchtime where I am here in Nevada right now so I just so happen to have a cheeseburger uh sitting in front of me it's technically a veggie burger um I'm not vegetarian but I I do
• 08:00 - 08:30 appreciate a good veggie burger and uh using beef as our example here provides us a good uh array of talking points really to take a look at some energy transformations so we're going to think about this cheeseburger in the context of energy transformations from a biological standpoint um thinking about mushrooms um as well as the the bun side of our Burger including pickles tomatoes and lettuce this and then we'll we'll
• 08:30 - 09:00 take a look at the the beef part of the cheeseburger and the Transformations there so if we start with mushrooms you may be a mushroom fan um I certainly am but uh in addition to the consumption of mushrooms that I enjoy I also recognize the important value of mushrooms and other fungi as well as other microbes to the process of decomposition so this transformation on Earth is incredibly important um dare I say it's among the
• 09:00 - 09:30 more important Transformations and decomposition as a process is actually cellular respiration it's the same process of taking um materials in this case we're talking about decomposers using dead plant and animal remains as their source of energy and we're thinking about biological Transformations this is electrons and also utilizing that carbon source for their carbon um just like you would think about in a cellular respiration
• 09:30 - 10:00 pathway and really when you get down to it and you think about cellular respiration it's like a little combustion reaction that happens in cells if we take a look at the chemical equation below we start with glucose um and oxygen and uh what happens from that reaction is a quite a bit of ATP some heat and also carbon dioxide and water as waste products and heat is important here because it is indeed something that
• 10:00 - 10:30 happens as a consequence of that second law of Thermodynamics there's always heat being released in these kinds of of catabolic reactions and there's a lot of energy associated with that glucose molecule so the majority of it will go towards heat and ATP and then some of those waste products carbon dioxide and water don't really make good forms of energy so we tend to kind of put them over in in for this equation anyway sort
• 10:30 - 11:00 of on the waist scrap heap of things so some of that biomass that is being decomposed is transformed into the biomass of the microbial decomposers themselves so where do mushroom bodies come from they come from the food sources that these microbes are breaking down and so then that biomass can go and be consumed by other consumers uh within a food web in addition to those Transformations uh things like um nitrogen and phosphorus that are are
• 11:00 - 11:30 organic forms of those molecules can also be recycled through this decomposition process which is another important facet um to inorganic forms that plants can use and then we can start to think about what that means uh for the rest of the ecosystem and to think about decomposition in a bigger scale way to think about this process across the globe we are looking at a time where climate change and temperature effects
• 11:30 - 12:00 um ultimately impact everything uh decomposition included and one of the ways that uh warming temperatures influence decomposition is through the uh kinetics of microbial activity so the warmer the temperature microbial metabolism increases so that means the composition rates increase uh potentially dis disappearance of materials increase and also the transformation to carbon
• 12:00 - 12:30 dioxide also increases another thing that can happen um as a consequence of fossil fuel combustion leading to Global Climate Change is that that process of combustion also releases more nitrogen to the atmosphere that can in turn return to soils and that can actually decrease decomposition rates there's been some information that suggests that decomposition rates can decrease not increase um as a consequence of the kinds of um the the things that
• 12:30 - 13:00 are that microbes are naturally accustomed to in those locations and same thing for plants we can see some really unusual changes happening there um maybe un unintended kinds of consequences um and decomposition cannot be overstated as being incredibly important we think about decomposition as being the sort of the end of the line for life but really it's the bookends of life the end of life um but it's also
• 13:00 - 13:30 important to the beginning of life because this is an important part for recycling and I really like this quote from uh biogeochemical ecologist uh n noher who says life would end without rot and I think that's a really good way to look at the importance of decomposition in every ecosystem and you may not be aware of the fact that there's actually a special group of organisms that is responsible for decomposition and freshwater
• 13:30 - 14:00 ecosystems um of course microbial decomposition happens all over um deserts to Wetlands to uh forests um so of course it happens in aquatic environments too and both fungi and bacteria play a pretty important role in the decomposition of leaf litter and freshwater environments but as I mentioned a very specialized group of aquatic fungi um called The Aquatic hyphomycetes are um integral to this
• 14:00 - 14:30 process they make spores they actually sporulate underwater and then those spores can move along and settle on Leaf litter and you can see from the little diagram here below the arrow they have some really amazing looking shapes they're actually very well uh adapted to being able to grab onto like a tripod wood uh to a leaf litter surface and then those are the spores that you're looking at and then they can um start to vegetate throughout the leaf
• 14:30 - 15:00 litter itself and grow and thence exoenzymes and so they go about breaking down litter similarly to the way you would expect that to happen on land and just like on land decomposition rates are controlled by a wide variety of both biotic and abiotic factors so things like the leaf species and the chemical composition of the litter um this relates a lot to the proportion of lignan um because these are leaves from
• 15:00 - 15:30 trees and so the amount of lignan present the more lignin the the more challenging it is to break down these leaves um nutrient concentrations in the leaves themselves and also in the water matter a lot um nitrogen and phosphorus U that function as as effectively fertilizers for all living things because those are necessary um for for life and then also temperature effects so we see some pretty strong controls on temperature effect effect an aquatic fungi uh the same way we would
• 15:30 - 16:00 temperature control effects on on other kinds of microbes and so when we take a look at this uh role of transformation that aquatic fungi play in in leaf litter we can see that we are looking at effectively a food web moving from Leaf litter where the fungi are as well as bacteria um conditioning that leaf litter for uh macro inverte that are themselves DET travores so in freshwater
• 16:00 - 16:30 environments those macroon invertebrates are usually larvae or juvenile forms that are consuming that leaf litter as well as the microbes so they're eating both of those things um and then that in turn will be energy that's transferred to um to adult macroinvertebrates when they emerge um often with wings and leave that location and then of course those in turn may be consumed by Predators like this uh fish that we see
• 16:30 - 17:00 here so aquatic fungi as you can see are pretty important uh in this role of transformation from dead leaf litter to their own biomass also making carbon dioxide that we'll take talk about in just a second um and then of course that biomass channeling up to other consumers within that food web so another pause and reflect moment for you uh to think a little bit about some other ways that you may be familiar
• 17:00 - 17:30 with already that decomposition as a process transforms materials that can be useful to us so think about this one for just a minute or two and then we'll return to the video all right so carrying on our tour through uh energy transformations in our cheeseburger model here we're going to take a look next at what goes on this
• 17:30 - 18:00 side of energy transformations thinking about the bun as well as pickles and tomatoes and lettuce so you could you could choose your favorite photosynthesizer here but you guessed it we've arrived at thinking about photosynthesis um so photosynthesis is an incredibly important process this is the start to most ecosystems on Earth um certainly the ones that we as humans are engaged with on a regular basis and
• 18:00 - 18:30 photosynthesis is important because it is the way by which inorganic carbon uh as CO2 primarily but also as some other forms of of inorganic carbon is um utilizing solar energy to be able to turn that into organic forms of carbon so we could talk about that as glucose or sugars or saying it's organic carbon um but ultimately what plant and other photosynthesizers are doing is
• 18:30 - 19:00 utilizing this process and then creating ultimately things like cellulose which is what you see when you look at a plant body that's the fiber that you eat or starch that we can also consume that's a storage product for plants But ultimately um when you take a look at this equation we've got carbon dioxide and water powered by solar energy here and sunlight energy and then at the end of this process as the products we get glucose as well as oxygen um and when you take a
• 19:00 - 19:30 look at this equation and think back to what we saw with cellular respiration you may note that those processes are roughly reciprocal with each other so we've got some differences in the amount of ATP used and gained and things like that but this process is reciprocal with cellular respiration so what you get out of products from photosynthesis uh sugar and oxygen those in turn become the reactants that we see in cellular
• 19:30 - 20:00 respiration so what this means is that this transformation alone ties consumers just like us immediately to the plants and producers so even if you don't like your vegetables and you don't like to eat kale you have to recognize that these plants around the world including the ones that we don't consume like algae for example you may be an algae fan but you might not be eating algae in in ocean systems that are pretty important to Global photo uh photosynthesis without those producers
• 20:00 - 20:30 on the planet those ecosystems that we depend upon for services wouldn't be here and we wouldn't be here so um that is a an integral part of of the world that we know and the Transformations that are necessary and if we take a little diversion down a couple of different roads for just a second and think specifically about that hamburger Bond and think about the value of wheat um and where our wheat comes from how valuable it is as a food crop it
• 20:30 - 21:00 accounts for about 20% of the calories consumed by humans it's also under threat from global climate change uh primarily because of temperature shifts and drought that then lend themselves to problems with water supply and in fact uh global climate change is already impacting about 15% of wheat production globally and may likely um quadruple that in the next 20 to 50 years or so and the greatest threats on Earth are
• 21:00 - 21:30 what we see in developing nations um across the globe so wheat an incredibly important crop um and also uh under threat but if we think about solar energy in another way so solar energy that relates to photosynthesis but if we think for a minute about how we can directly use solar energy that brings us to considering um solar power and we are kind of in a remarkable place and moment in time because as of about um a week or
• 21:30 - 22:00 so ago here in October of 2020 for the first time um solar power has become the cheapest electricity Source in history that's a pretty phenomenal statement to be able to make uh since 2018 solar power has provided about 26% of global electricity and due to uh lowering costs that is likely to become um a greater proportion as we move forward which is pretty amazing um and solar energy is
• 22:00 - 22:30 also flexible uh it can be harnessed on a variety of scales um you could talk about uh passive versus active solar in your home but if you're thinking about a large scale use of solar energy um a couple of things come to mind uh photovoltaic or PV energy that's used in solar panels so this is we're actually harnessing the power of photons in sunlight um also you could harness the power of heat in sunlight as is What's Done in solar thermal
• 22:30 - 23:00 energy electricity generation so in this process Heat's concentrated um on some reflective panels and then usually U moved up towards a tower that has um mol and salt um where it's absorbed and circulated that then gets to water um and that water is heated to steam that steam turns a turbine that turbine then generates electricity so this is kind of the classic throw uh throw flow through pathway uh for looking at um electricity
• 23:00 - 23:30 Generation all right so then this brings us to our uh third component of thinking about this cheeseburger model for energy transformations and that is beef and there are lots of energy transformations that we could consider when we're thinking about beef and the production of it so we start from grain
• 23:30 - 24:00 uh and think about what it takes to build beef and cows and we're going to chart this course all the way through to methane and Beyond so first of all to make this statement cows eat fossil fuel seems like an odd thing to say but when you really start taking a look a little closer um they are a major connection to fossil fuels um the production of feed itself account accounts for about 75% in
• 24:00 - 24:30 fact of fossil fuel use in livestock Agriculture and how is this um it's through the production of nitrogen fertilizers so so fertilizers that are used to grow plant crops uh corn and soy crops um in particular and and other kinds of grain Alfalfa if we're thinking about grasses for hay for cows um are made from natural gas and natural gas contains methane um so the process of creating nitrogen fertilizer utilizes uh
• 24:30 - 25:00 hydrogens from methane to fix nitrogen and so that is pretty integral to the production of feed that then goes to feed cows um so an interesting way to think about this is to say that cattle when they're alive not only consume living plants in the food that they consume but they're also consuming long dead ones in the form of fossil fuels and here's a really interesting note uh this is from agricultural ecologist uh David Pim who's done a lot of work looking at agricultural systems and uh
• 25:00 - 25:30 Global kinds of processes as well that a typical steer will quote unquote consume so this is not directly but a wide variety of indirect consumptions um about 284 gallons of oil in its lifetime um that's a pretty remarkable statement to make so clearly fossil fuels have a huge role in the um processing and and
• 25:30 - 26:00 agriculture of animals so not just processing but also packaging shipping we haven't even gotten to thinking about uh the food once it gets to you so Refrigeration cooking all the Preparatory steps that then lead up to that cons consumption of 284 um gallons of oil and also if you think about the goings on in an intensive confinement operation or a
• 26:00 - 26:30 factory for Farm sometimes these are called Kos in addition to utilizing fossil fuels in this process they also use a lot of water so the operations of animal agriculture also take a lot of water to make happen um not just the water that's used for cleaning and sanitation maintenance and those kinds of things but also and you may have never thought about this one that water is also so needed to take fossil fuels
• 26:30 - 27:00 around from place to place so the conveyance um of fossil fuels often times does require energy to move plus the virtual water that's used in Crop Production so virtual water means that this may be water that's used in one place that is then ultimately consumed in somewhere else or some other location so if crops are produced on one continent and those crops are shipped overseas to be consumed by animals where they are that's effectively water that
• 27:00 - 27:30 was that was utilized somewhere else but is being consumed in another location so that's what virtual water here refers to so water um is also a big part of what goes into these kinds of Transformations and then that brings us then to thinking a little bit more about methane and some of the special case importances of methane as well as other greenhouse gases so animal agriculture as a process contributes in pretty significant ways to uh uh Global um greenhouse gas
• 27:30 - 28:00 emissions about 73% of all nitrous oxide gas to the atmosphere comes from uh soil fertilization as well as animal waste management and about 94% of all agricultural methane this would be all kinds of agricultural processes um come from animal Agriculture and that's mainly through enic fermentation which is pretty important um and also through uh Solid
• 28:00 - 28:30 Waste Management so that's a lot of methane potentially that's being produced through processes that relate to animal Agriculture and just uh an additional special word about methane so since the last century uh the production of methane has increased pretty significantly by about 150% um methane accounts for about 10% of all human produced greenhouse gases so even though that slice is small
• 28:30 - 29:00 relative to carbon dioxide it's getting bigger and some features of methane the molecule that make it different and a little more uh dangerous and challenging than carbon dioxide is that it has about 25 times the heat retentive properties um that carbon dioxide does and uh can last for about 10 years as methane in the atmosphere before it's oxided ized to CO2 um when we take a look around the
• 29:00 - 29:30 world and look to see where the primary sources in addition to some inputs from agriculture but the primary sources of methane are globally it comes from surprise surprise or maybe not um organic matter decomposition and particularly that that's happening in low to no oxygen environment so places like wetlands and sediments associated with Wetlands sediments associated with Lake Reservoir ecosystems where microbial
• 29:30 - 30:00 decomposition just like it is anywhere on Earth is being controlled by temperature um and also primary sources are increasingly being associated with places that were um previously frozen that are continuing to or beginning to thaw so permafrost um Arctic lakes that are frozen and the sediments associated with those locations so warm up the planet and you have the increased likelihood of
• 30:00 - 30:30 decomposition uh in anerobic environments that can lead to methane production um and also fossil fuel deposits is a primary source so uh methane from fossil fuels and where you find fossil fuels can be released during extraction of those fuels can be released during um leaking of those fossil fuel deposits you might also be familiar with methane associated with landfills so pretty much anywhere you have or organic matter that can decompose under low to no oxygen
• 30:30 - 31:00 conditions um you you run the risk of having methane inputs so if we put all of these things back together again and think about now instead of mushrooms we see mushrooms as a symbol for decomposition um the bun and all of those veggies we think is symbolic for photosynthesis and um the beef here in our cheeseburger we think as as symbolic for com consumption we can kind of see
• 31:00 - 31:30 how all of these energy transformations all relate to each other so decomposition is a process as we talked about the energy of decomposition goes to microbial biomass and it also goes to other consumers um it also refers back to the production of carbon dioxide and that immediately then ties us into photosynthesis as a process um decomposition I comes from dead plants
• 31:30 - 32:00 and also from dead consumers so we can look at the reflexive nature of those arrows uh within our cheeseburger model here if we move on to thinking about photosynthesis as a process where is that energy um going it's going to Consumers of various kinds um it's also coming from if we ask the question where is energy coming from it's coming ultimately from sunlight and we also took a detour thinking about the energy
• 32:00 - 32:30 production that we can harness um through sunlight for solar power for a variety of different applications and then finally for consumption um we have the energy that is to Consumers and also two fossil fuels but then of course where is that energy coming from it's coming from Plants um and of course microbes at some level and also from fossil fuels which themselves in turn are ultimately coming from plants and
• 32:30 - 33:00 previously dead things um and that process of partial decomposition or decomposition so uh this brings us to our last opportunity together to just pause and reflect uh for a minute and I'd like for you now to think a little bit about how all of these connections these Energym made and energy used connections not just uh connect to the object that you thought about before but
• 33:00 - 33:30 now I'd like for you to take a little bit more time um as we close out today um to think about these Connections in the context of an issue that may have sparked your interest from previous units um in your course so maybe this relates to population dynamics of human populations or maybe even nonhuman populations um maybe it's a question of natural resource use or natural ource conservation from forested ecosystems or
• 33:30 - 34:00 maybe agricultural ecosystems like we've touched on a little bit today or perhaps aquatic ecosystems are your favorites freshwater marine ecosystems so I'd like for you to to think for a moment about how those connections and the complexity of those connections really do influence the ways that we um take a look at our world and those biological underpinnings that really do make our
• 34:00 - 34:30 world go round so thank you very much uh for being here today I appreciate your time and your attention and uh continue to have a great apes year