The purpose of this lesson is for you to review key concepts from Lesson 1 (Energy and Sustainability) of EMSC 240N. I strongly encourage you to at least browse through Lesson 1 [1] of EMSC 240N, though that is not required.
By the end of this lesson, you should be able to:
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To Do |
Lesson 1 Quiz Lesson 1 Journal Entry Lesson 1 Discussion Board Post #1 |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
Thermodynamics is defined by NASA [2] as "the study of the effects of work, heat, and energy on a system." Any time you discuss energy transfer, assess the efficiency of a piece of equipment, or analyze the conversion of energy from one form to another, it involves thermodynamics.
Energy is defined as "the ability to do work," and work is the transfer of energy or the application of force across a distance. If this were a Physics or Thermodynamics course, we'd be more concerned about work, but for better or worse it is not, so we will stick to focusing on energy. For the purposes of this course, there are a few important things to remember about energy:
The following discussion of energy forms is taken nearly word-for-word from EM SC 240N. Direct quotes are from this reading from the National Energy Education Development (NEED) Project [3], which you are welcome, but not required, to read.
The two categories of energy are potential and kinetic. Potential energy is stored energy and kinetic energy is energy in motion. The forms of energy are as follows:
Differentiating the various forms of energy is usually straightforward, but I have noticed that people often confuse thermal and radiant energy. This is probably because most people associate "thermal" with "heat," so when something generates heat, it is assumed that thermal energy is being released. Please keep in mind that radiant energy travels in waves, and is released by everything above absolute zero (humans have never observed absolute zero). Radiant energy emanates in all directions from everything, and the hotter the object, the more and more intense radiant energy it emits. All radiant energy is invisible to the human eye except for energy in the visible spectrum. Thermal energy, on the other hand, is energy in the vibrating molecules of a substance. Again, everything above absolute zero has thermal energy, i.e., its molecules are vibrating. Thermal energy is contained within the molecule(s) and is not emitted.
Energy is constantly changing forms all around you (and everywhere else on earth) all of the time. All forms of energy can end up as all other forms of energy, and recall that the First Law of Thermodynamics dictates that all energy, irrespective of its form, comes from somewhere else. Again, the following is taken almost word-for-word from EM SC 240N.
Take a few minutes to look around you. Based on what you know about energy, what is energy “doing” where you are right now? What forms can you identify? (Seriously, take a look.)
Considering I can't see you right now (Or can I? Hmm...), I'll just give you a few probable examples. If you are inside, light is coming from somewhere, whether it’s a light bulb on the ceiling, sunlight coming through a window, or at least coming from the screen you are looking at (this is electromagnetic/radiant energy). Any sound you hear is sound energy. Everything around you is radiating heat, which is a form of radiant/electromagnetic energy. Since everything in and around you has a temperature above absolute zero, it has vibrating molecules and thus thermal energy. If you are moving at all - even the slightest twitch of an eyelid - your body is using motion energy. Merely thinking about this question requires your brain to use electrical energy.
We could go on and on. But as you probably know, these are all examples of kinetic energy. There are also a number of types of potential energy around you. Think of some examples of potential energy around (and in) you right now. You are able to move and think because of chemical (potential) energy inside of your body. In fact, everything around you has chemical potential energy. Any object on the wall, on a table, attached to the ceiling, or just above the ground has gravitational (potential) energy because it is above the ground. There is also nuclear (potential) energy in all matter because all matter has at least one nucleus. Again, we could go on and on, but the point is that everything around you has potential energy, and thus has the ability to do work, i.e., “to make things happen.”
All of the examples of energy that were noted above came from somewhere else. The light coming from a light bulb is converted from electrical energy running through a wire. The heat radiating from non-living things around you was absorbed from another source such as sunlight or the heating system of the building. The motion and electrical energy your body has right now come from the chemical energy inside of your body. The gravitational energy of things around you came from motion energy required to lift the objects. And so on. And recall that each time energy was transferred, work was done.
Efficiency is an often used term when discussing energy, e.g., "I have an efficient car," "How efficient is your furnace?", and "The average efficiency of a coal-fired power plant is around 33%." Though the term is thrown around a lot, it has a specific meaning. Energy efficiency is the amount of useful output per unit of input. The "useful" part of that definition is important since the First Law of Thermodynamics requires that all energy that goes into something must go somewhere.
The video below provides a very good explanation and animation of how a coal-fired power plant works. Think it's as easy as dumping a bunch of coal into a furnace and turning a turbine? Watch the video to find out.
All energy-using (and generating) technologies have an efficiency - TVs, light bulbs, solar panels, cell phones, wind turbines, airplane engines, electric motors, you name it. One important aspect to know is that when energy is converted, it is physically impossible to convert all of the energy into useful output. In other words, it is not possible for anything to be 100% efficient. This is dictated by the Second Law of Thermodynamics. The Second Law has other implications, but they are not important in the context of this course. If you'd like to learn more about the Second Law, see the video below and/or this [8]link.
The second law can be confusing, but the narrator in the video below does a pretty good job of explaining some aspects of it.
Renewable energy is defined by the U.S. Environmental Protection Agency [9] thus: "Renewable energy includes resources that rely on fuel sources that restore themselves over short periods of time and do not diminish." Non-renewable energy is energy that cannot restore itself over a short period of time and does diminish. It is usually easy to distinguish between renewable and non-renewable, but there are some exceptions (more on that in a minute).
Fossil fuels are fossilized hydrocarbons made from organic material. They are considered "fossilized" because they take millions of years to form, they are hydrocarbons because they are made mostly of hydrogen and carbon, and of course organic material refers to living or recently living things.
The three primary fossil fuels used in the world are coal, oil, and natural gas. (As noted in EM SC 240N, oil and natural gas are technically made up of multiple hydrocarbons, but they are each conventionally referred to as individual hydrocarbons.) Feel free to read through the U.S. Energy Information Administration's (U.S. EIA's) summaries of coal [10], oil [11], and natural gas [12] before reading the summaries below.
Since all fossil fuels started out as plants or animals, all of their energy comes from the sun. The solar energy (all radiant energy) is stored as chemical energy when the plant undergoes photosynthesis, then is stored as chemical energy in the fossil fuel itself. It is (usually) released when the fuel undergoes combustion, which results in thermal and ultimately radiant energy release. Note that the physical material of fossil fuels does not come from the sun - the carbon, for example, is pulled from the atmosphere during photosynthesis - but the energy that is released when coal, oil, or natural gas is burned was once solar energy.
Nuclear energy, as discussed above, is the energy that holds the nucleus of atoms together. Nuclear energy in nuclear power plants is extracted using fission of uranium atoms. Fission releases radiant energy, which is used to heat water to steam and turn a turbine, which spins a generator and generates an electrical current. The sun utilizes fusion (fusing hydrogen together to form helium atoms), which then releases radiant energy.
As noted above, renewable energy sources "restore themselves over short periods of time and do not diminish." For a thorough explanation of many renewable energy sources, see this site from the U.S. EIA [13]. A more thorough explanation of these sources is provided later in this course.
As you are no doubt aware, a primary sustainability concern regarding energy use is carbon dioxide (CO2) emissions. A carbon-free energy source emits no carbon when energy is being generated. Solar, wind, hydroelectric, and nuclear energy are commonly used carbon-free sources. Carbon neutral sources release CO2 but have no net impact on the CO2 concentration of the atmosphere because they release no more CO2 than was absorbed from the same atmosphere. Biomass is the only carbon-neutral source of energy. Recall that biomass gets its energy from the sun by virtue of it being used by photosynthetic organisms to grow. Biomass is made mostly of carbon, which is integrated into the biomass when CO2 is absorbed from the surrounding air. When said biomass is converted to useful thermal/radiant energy via combustion, the same or less CO2 is released, resulting in a net zero impact on carbon dioxide concentrations. To summarize:
It will help to at least skim through this page of EM SC 240N [18] prior to reading this material, but it is not necessary.
As I'm sure you are aware, the terms sustainable and green are used in many contexts and in many sectors of society. Sustainable growth, sustainable energy, green business, sustainable fashion, green cars, sustainable food, and sustainable consumption are just a small sample of how the terms are used. Many people in the sustainability field (myself included) are concerned that the term has been overused to the point that it is almost meaningless. Robert Engelman, President of the Worldwatch Institute [19], refers to this phenomenon as "sustainababble" in his "Beyond Sustainababble [20]" chapter from Is Sustainability Still Possible?. While this excessive usage of the term is undesirable, it is in some ways understandable because a) sustainability relates to everything that humans do and b) it has become an effective way to market products. Selling stuff to the masses drives the economy (consumer spending historically [21] constitutes around 65% - 70% of U.S. GDP), though such rampant consumerism ironically has a largely negative impact on sustainability. You may recall that EM SC 240N was largely designed to cut through a lot of this "sustainababble," and help you understand what sustainability really means. This course will offer a review of a lot of the concepts in that course, as well as provide some additional ones.
See below for a summary of key sustainability points from Lesson 1 of EM SC 240N:
Sustainability and sustainable development are often thought of as having three core components: environment, economy, and equity. These are commonly referred to as the "3 Es" of sustainability. The 3 Es is a useful way to provide an analytical framework for sustainability. This 3E framework is useful because it provides questions that can be asked when investigating whether or not something is sustainable. While even these terms can be defined in various ways, we will use the following definitions from the reading when analyzing the sustainability implications of something:
The following provides a few more details about each of the 3 Es:
I have a challenge for you: think of something that you did in the past week that did not involve energy.
Okay, so that's not really a fair challenge. Everything we do, even thinking about things that we might do, requires energy. Here's a more reasonable challenge: think of something that you did in the past week that did not involve the use of non-renewable energy.
Any food you eat almost certainly required non-renewable energy. There are obvious connections like farm machinery, artificial fertilizers, and herbicides, transporting food, refrigerating food, cooking food, and packaging food. But even if you grow your own, you likely used a tool or fencing that was manufactured using non-renewables, seeds that were processed and shipped with fossil fuel-using machines, packaging that was made using non-renewable energy, or maybe even plastic row markers made with petroleum-based plastics. Almost all transportation uses non-renewables, most businesses run on non-renewable energy sources (either directly or indirectly through electricity generation), almost all of the products you buy contain materials either made of or that are processed with fossil fuels. The electronic device you are looking at right now is partially made of and manufactured using fossil fuels. In short, modern society is very dependent upon access to non-renewable energy, particularly fossil fuels. As Asher Miller notes in The Post Carbon Reader:
Look around and you'll see that the very fabric of our lives - where we live, what we eat, how we move, what we buy, what we do, and what we value - was woven with cheap, abundant energy. (p. xiv)
The charts below provide some insight into the U.S. and global energy regimes. The first chart is from the International Energy Agency, and the other is from the U.S. EIA. Both are excellent sources of energy information. Please take a look at them and read through the descriptions, and keep in mind that there is one final summative point provided below.
There are a few interesting things to point out from the chart above.
The charts below provide rather dramatic evidence of how important non-renewable energy is to the U.S. Both charts are from the EIA's Annual Energy Outlook (AEO) series, which are published on a yearly basis. A few things worth pointing out:
It should be clear that the vast majority of energy used worldwide comes from non-renewable sources, and this is unlikely to change any time soon. This has a lot of sustainability implications, which we will address in more detail later. From systems thinking perspective, it is important to realize that everything you do requires energy, and it is important to think about where that energy comes from and what the sustainability implications are.
That's it for Lesson 1! Hopefully this review helped solidify these concepts for you. By now you should be able to:
Double-check the to-do list on the Lesson 1 Overview page [28] to make sure you have completed all of the activities listed there before you begin Lesson 2.
The purpose of this lesson is for you to review key concepts from Lesson 2 (Fundamental Sustainability Considerations) in EM SC 240N. I strongly encourage you to at least browse through Lesson 2 [29] of EM SC 240N, though that is not required.
By the end of this lesson, you should be able to:
To Read | Lesson 2 Online Content | You're here! |
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To Do |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
Externalities is one of the more nuanced concepts from EM SC 240N, so I am giving it its own page. This is mostly a summary of EM SC 240N's version.
At this point, I'm sure you are all familiar enough with basic economics to know these three fundamental principles:
The first two are not very controversial - if very few people want something (it has low demand) then it makes sense that companies would need to drop the price to sell it, and if something is in high demand, a company can charge more. Also, as the price of something rises, it makes sense that fewer people would want (or be able to) buy it, and vice versa. (It should be noted that some goods can be "inelastic" to a certain degree, which means that a price increase does not reduce demand by much and/or a price drop does not increase demand by much. Oil [31]can be inelastic under certain conditions, for example.)
The third point makes a lot of sense, too. If I go to buy apples and I go to the grocery store and see two different brands of the same apples (probably Honeycrisp, since my kids are obsessed with them) side-by-side, but one is cheaper than the other, I'll probably buy the cheaper one. The same type of decision-making process goes into most economic decisions that you make, whether it involves clothes, cars, where to go out to eat, which detergent to buy, which cell phone to purchase, and so on. You ask yourself: "Is it worth it to buy this product or that one?" and this is based on the price combined with the perceived value of the good. This lies at the heart of modern economic models.
Thus, the price of something is an essential consideration in how much of it is used, and thereby produced. But how is the price determined? In simplified terms, all of the costs that go into getting the product to the end user should be reflected in the price. For my Honeycrisp apple, the costs of at least the following should be included: the farm (paying for seeds, workers, growing equipment, etc.), the company that shipped the apple to the store (paying for workers, fuel to drive the trucks, people to arrange logistics, etc.), and of course the grocery store (paying workers, electricity bills, paying investors, insurance, etc.). These and any other costs associated with getting the apple to you should be covered. Otherwise, the businesses lose money and won't be able to stay in business much longer. In sum, all of the costs to get the good to you should be included in the price. Seems pretty straightforward, right?
As you may remember, it is not always this simple. All of the apple-related costs included in the price that was noted above are internalized, that is, they are reflected in the price. But can you think of any externalized costs, that is, costs that are not reflected in the price? Examples may include:
There may also be some external benefits involved with the process of getting the apple to you. Possible examples include:
There are many more possible impacts that are not included in the price of the apple. All of these would be considered externalities, as long as they were not included in the cost. The OECD offers a reasonably good, concise definition of externalities:
Externalities refers to situations when the effect of production or consumption of goods and services imposes costs or benefits on others which are not reflected in the prices charged for the goods and services being provided
(Please note that some economists consider anything that happens to someone that was not directly involved in a transaction an externality whether or not that "anything" is included in the price. In this course, we will only consider it if it is not included in the price.) Before moving on, feel free to watch the video below. The most relevant parts are the first 3:20 of the video and 5:06 - 6:22.
As noted in the video, there are usually external costs and/or external benefits to transactions. External costs and benefits are borne by people or other entities that had no input on the transaction and were not fully included in the price. A negative externality occurs when an external cost occurs, and a positive externality occurs when an external benefit occurs.
There are a few important sustainability implications of externalities:
In sum, externalities are by definition not included in the cost of goods. Positive externalities, which are usually good for sustainability, do not occur as often as they should because the benefit is not included in the price. Negative externalities (which are more common, by the way) happen more often than they should because their cost is not included in the price.
Without getting into the specifics about the probable causes of climate change (that will be covered in the next lesson), let's take a look at climate change as an externality. As you will see in the next lesson, if the climate continues to change, the impacts will be overwhelmingly negative. Quantifying these costs is an active area of research, but many countries - including the U.S. - have placed an "official" cost on the emission of carbon dioxide (this is used to calculate the cost of new legislation). Under the Obama administration, the U.S. federal government used a social cost of carbon (SCC) of $39 per tonne [32]of carbon dioxide. (Not surprisingly, the Trump administration has proposed to lower this significantly.) A 2015 study out of Stanford University [33] found that the U.S. grossly underestimated the SCC and that it should be closer to 220 dollars/tonne. In 2013, major corporations integrate the cost of carbon emissions into their projects [34] (between 6 dollars and 60 dollars/tonne), though they use some different considerations than SCC, and by late 2016 hundreds of companies [35] worldwide had integrated SCC internally.
There is a lot of material to these points and it is very important, so here is a summary of the key points:
I'd like you to consider these two basic truths:
Just as a business that loses more money than it makes runs a deficit, when humans overuse the capacity of the earth to replenish resources, it could be said that these places are running an ecological deficit. In this scenario (see the image below for an example), our stock of natural resources will diminish.
It is relatively easy to determine the number of trees (or other plants) that a farm can grow in a year. The earth, of course, provides a lot of other natural resources that are useful and/or important for humans (absorbing CO2, providing oxygen, providing food, replenishing the soil, etc.). Combined, the amount of these resources sustainably provided in one year can be considered one "earth's worth" of resources. If we could figure out this "one earth" and compare it to how many of these resources we use, we could determine if we are losing or gaining ecological capacity. This is where the concept of ecological footprint comes in.
Feel free to watch this short video from Mathis Wackernagel, who originated the concept of ecological footprint. He is currently Executive Director of the Global Footprint Network [37], which specializes in calculating ecological footprints.
This all points to the importance of ecological footprint. Ecological footprint can be defined as follows:
"Ecological Footprints estimate the productive ecosystem area required, on a continuous basis, by any specified population to produce the renewable resources it consumes and to assimilate its (mostly carbon) wastes."
~Jennie Moore and William Rees, "Getting to One-Planet Living", p. 40
The beauty of ecological footprint is that it provides a specific area of land and water that must be used to sustainably provide the resources necessary to support a person or population. (It is impossible to know the exact area needed, but we can derive a good scientific estimate.) From a sustainability perspective, it follows that if a person or population is using more land/water area than they have available to them, they are living unsustainably. On a global scale, if humans are using more resources than the earth can sustainably provide (one earth), then they are living unsustainably, and the earth's capacity to provide resources will diminish. This is where we are right now, as you can see in the image below.
The key points related to ecological footprint are as follows:
Finally, I'd like to remind you of the concept of overshoot and collapse. Overshoot and collapse refers to a situation in which a critical threshold has been surpassed, but the full negative impacts of crossing that threshold have not yet become apparent. By the time those impacts have become apparent, it is too late to remedy the situation. (Feel free to read the description of what happened on St. Matthew Island [39] cited in EM SC 240N.) Humans are by-and-large good at responding to feedback, so when a situation occurs that does not provide immediate feedback, we tend to have difficulty addressing it. Climate change is unfortunately a prominent example of this because by the time the worst impacts have become reality, it will be too late to do anything about it unless we can rapidly remove the greenhouse gases from the air.
Energy return on energy invested (EROI) is a fairly straightforward concept. The following summaries key concepts and terms regarding EROI:
Here is the equation. (Note that "quantity of energy supplied" is the same as end-use energy and "quantity of energy used in supply process " is the same as embodied energy.):
The images below provide a snapshot of sample EROIs of various fuels provided in a peer-reviewed article by Hall, Lambert, and Balogh called "EROI for different fuels and the implications for society [42]."
Why is EROI important? One of the main reasons is that EROI is more indicative of the true net energy benefit of various fuels than the end use. It takes about the energy from 1 barrel of oil to extract 20 actual barrels of "traditional" oil (it has an EROI of about 20:1), but the same amount of energy, when used to extract tar sands oil, results in only about 4 actual barrels. In other words, EROI indicates that you get about 5 times the amount of energy from traditional oil than from tar sand oil given the same amount of input. A very interesting finding in the Hall, Lambert, and Balogh article is that oil discovery in the U.S. has decreased from 1000:1 in 1919 to only 5:1 in the 2010s, meaning we get 100 times less energy now than 90 years ago! (Essentially, we have extracted most of the "easy to get" oil and do things like deep sea drilling now.) Getting ethanol from corn (recall from Lesson 1 that this is the U.S.'s primary source of biofuel) can require almost as much energy in as energy you get out, depending on how it is grown and processed.
EROI can help policymakers and others decide which energy source is a more efficient use of energy resources. In the context of this course, it is a particularly important consideration for non-renewable resources, because it indicates the net energy benefit of the sources.
One extremely important final thing to note: EROI only describes energy use. It says nothing about the other important impacts and factors. For example:
In short, EROI is only one consideration to be made.
If you listen to the news, pay attention to politics, or read about business activity (no matter where you live in the world), you know that it is taken as almost a given that economic growth is good, and should be pursued ad infinitum. But you may recall from EM SC 240N that not only is growth not always good, but permanent economic growth is impossible on a finite planet unless it can be done in such a way that the total amount of natural resources on Earth remains the same year after year. In other words, as stated by Herman Daly:
"An economy in sustainable development...stops at a scale at which the remaining ecosystem...can continue to function and renew itself year after year" (Herman Daly, "Sustainable Growth, an Impossibility Theorem," p. 45)
This is one of the main points of Herman Daly's seminal article "Sustainable Growth, an Impossibility Theorem." Feel free to read through this reading, which is posted in Canvas. The following are some other important points from the article:
All of the above summarizes the concept of the steady state economy.
Feel free to watch a video (5:07) featuring Herman Daly, himself, discussing the steady state economy:
It should not be difficult to recognize that humans are subject to the physical constraints of planet Earth. But how we make sure that we do not exceed our limit to the point of collapse (e.g., overshoot and collapse mentioned previously) is something that is debated, even by people with seemingly the same end goals. There is a branch of environmental (well, it's primarily economic) thought that is based on the power of free markets to most efficiently manage resources. This is often called free market environmentalism (FME). Those who advocate for FME believe that free markets (economic systems that are free from government regulation) are the best way to solve environmental problems. And, just as important, they believe that the government is much worse at managing resources than the market. This article from the Library of Economics and Liberty [46] (a free market think tank) summarizes the school of thought pretty well.
As outlined in this article, this school of thought rests on three assumptions in order for markets to work for any environmental good (e.g., a forest, clean water, clean air, etc.): "Rights to each important resource must be clearly defined, easily defended against invasion, and divestible (transferable) by owners on terms agreeable to buyer and seller" (source: Library of Economics and Liberty [46]). In other words, if a piece of property has:
I would add that (4) the author (and this is typical of FME) also assumes that the owner of the property is motivated to protect the property in anticipation of future profits.
For example, if I own a lake and someone pollutes it, if the courts are just, the polluter will end up paying me because (s)he compromised my ability to enjoy my property. If these conditions are known, then the polluter, in theory, will decide not to pollute in order to avoid the extra cost. As you can see, all of this relies on using money as the motivating factor.
This is a very sound argument as long as those conditions are met, at least in terms of environmental protection. This situation, and variations of it have been proven effective in a wide array of applications. It worked for water conservation in the Western U.S. [47] And here are a number of case studies [48] demonstrating that these principles can work.
But what if those four conditions are not met? With climate change, a fundamental question is: "Who owns the atmosphere?" (The answer: no one does.) If there is no clear ownership, the system may not work. Let's go back to my lake that got polluted, and think about a few plausible scenarios.
This article from the Property and Environment Research Center [49] - also an advocate for free-market environmentalism - goes over a few of these and other examples where the system breaks down.
It should be apparent at this point that humans cannot continue to live beyond the planet's ecological means and expect to survive. We have one "Earth's worth" of replenishable resources, and as we diminish that stock of resources by using them faster than they can be replenished and/or emit wastes faster than they can be absorbed, we reduce our ability to survive. Many different ways to achieve such a steady state economy (or something close to it) have been posed. Some people, such as Herman Daly, propose using taxes, incentives, and other policy-based solutions. Others advocate unleashing the power of economic markets to solve the problem, mostly through privatization. Please note that even the most ardent advocates [50] of regulation recognize that markets are extremely effective and efficient at allocating resources, but that they do not work well under a number of circumstances, e.g. when negative externalities artificially lower prices, and when impacts are not immediately felt (e.g. with climate change). Because of the massive externalities - particularly with regards to intergenerational equity, i.e. the impacts of today's actions will be felt by future generations - even free-market proponents recognize that it is not a problem that can easily be solved by markets.
Hopefully, by reading through and thinking about these issues, you will not simply take for granted that "growth is good," regardless of the circumstances or consequences. Daly himself concedes that growth can be good as long as it helps alleviate poverty, but ultimately we must reach a steady state economy if we are to establish a sustainable society.
GDP is the most oft-used metric to indicate how a country "is doing," economically speaking. But it is also widely used as a general indicator of how a country's people are doing. There is some usefulness to this, as you will see below. But GDP obscures a lot of possible problems (economic, social, environmental, etc.), and does not indicate all of the good things about society. In short, there are some things that are good for GDP that are bad for people, and there are some things that are good for people that are not necessarily good for GDP. This problem was eloquently described by Robert F. Kennedy in 1968. It is as relevant today as it was 50 years ago. Hopefully, this will give you some pause when you hear the latest GDP numbers as an indicator of how well a country is doing.
Quality of life is another one of those terms that is thrown around liberally but has no specific definition. We all want a high quality of life, but what does that mean exactly? I am not here to settle the debate, but I do like the definition from this website [51]: Quality of life is "the extent to which people's 'happiness requirements' are met." I'd add the term "satisfaction" in there as well, as in "are people's 'satisfaction' requirements met?" Nothing is universally regarded as necessary for happiness or life satisfaction. For example, I have friends who LOVE to hunt for deer and will sit for hours in a tree stand in the freezing cold, silently waiting for one to walk by. I can think of a lot of things that I'd rather do than that. But to them, that is an important part of their quality of life. Nothing wrong at all with that, by the way - it's just not for me.
Hunting is something that is obviously not universally required for a high quality of life. But I'm sure there are thousands, if not millions, of people who count it as important. But if you think about it, there is nothing that everybody loves to do, so it wouldn't matter which activity I used as an example. So, if we want to measure the quality of life, how do we do it?
Before we move on to the discussion of how to measure the quality of life, it is important to consider the concept of development. Development refers to how well the people in a country are doing, as in "How developed is country X?" or these are the "underdeveloped countries." Please note that many people (myself included) take issue with categorizing an entire country full of people using a single western-centric, judgmental term, which is why I use terms such as "(less) industrialized" or "high/low income" countries. These terms are objective descriptors, not judgments. Regardless, GDP and/or GDP/capita play primary roles in defining the level of development of a country, as do things such as having modern economic and political systems. There is some validity to this, but as RFK and others point out, GDP is not everything! A few more aspects of development worth pointing out (some of which are described in this reading from the World Bank [52]) are as follows:
There are many possible factors that contribute to the quality of life, or lack thereof. So how do we measure quality of life? For that, we need a quality of life metric. These are often referred to as development indices. Recall from Lesson 1 that it is important to be able to measure aspects of sustainability. Development indices are one aspect of this.
There are two approaches to this:
There have been many attempts to do the latter and a few that have tried to do the former. It would be impossible to research all of these, but some of the most used and/or most useful ones are listed below. The first two (HDI and Inequality-Adjusted HDI) measure things that lead to a high quality of life, the third one (Happiness Index) attempts to measure it directly, and the last one (Happy Planet Index) is a mixture of the two plus ecological footprint. Please note that even the best metric cannot create a full picture of development, however it is measured. Even the most "developed" country will have people who are living in poor conditions. Also, keep in mind that this is not a comprehensive list of development indices.
The Human Development Index is the most well-known quality of life metric. It was created by the United Nations (UN), who assesses it every year. It measures three things to determine quality of life, as you will see below: living a "long and healthy life, being knowledgeable, and hav(ing) a decent standard of living." The HDI scale goes from 0 (the worst possible) to 1 (the best possible). Feel free to read the description from the UN here [53], and browse through the ratings here [54].
The UN also publishes Inequality-Adjusted HDI (IHDI), which takes HDI and discounts it according to how equally the individual development metrics are spread across the population. If the Inequality-Adjusted HDI is lower than a country's HDI, then there is some inequality. As noted by the UN, the IHDI represents "the loss to human development due to inequality." The more inequality, the more the HDI score drops when adjusted for inequality. Note that the pattern in the map below is similar to the HDI map above, but the raw values are a little bit lower. Feel free to read more about IHDI here [57].
The World Happiness Report asks people to indicate on a scale of 0 - 10 their quality of life now and their expected quality of life in the future (see World Happiness Report details here [60], if you'd like). The basic premise behind this is that if you would like to determine how happy or satisfied someone is with their life, just ask them. This is a type of self-reported quality of life and results in a score of 0 - 10. This is sometimes referred to as the Happiness Index.
Pretty simple, right? Though it does beg some important questions. For example, if someone lives a short life with little education, but they are happy, does it matter? What about someone that has very little freedom, but is happy? What if they have almost no money, but are happy? What if others in their country lead much "better" lives, but they do not know it? I do not have the answers, but they are important questions to think about.
Last but not least, we have the Happy Planet Index. This index takes into account both well-being (they use the same metric as the Happiness Index), life expectancy (like the HDI), and inequality of outcomes. The higher your well-being and life expectancy, the higher your score. Inequality is expressed as a percentage, with a higher percentage meaning more equal outcomes. But what is unique about the Happy Planet Index is that it divides by the ecological footprint, so a higher ecological footprint will result in a lower score, and vice-versa. Nic Marks created this index. He describes it in the short (1:54) video below if you are so interested. Also, you can read more about HPI here [61].
There is no single definition for social justice, but take a moment to think about the definition of social justice from the National Association of Social Workers [62], who provide a good, concise definition:
Social justice is the view that everyone deserves equal economic, political and social rights and opportunities.
Ultimately then, social justice is about equal rights and opportunities, which is a near-universal ideal of democratic and moral societies. Not so bad, right? But let's unpack that definition a little before we move on.
First, it is important to point out that they use the word, everyone. This seemingly innocuous word actually lies at the core of social justice! I'm sure you can think of many historical and contemporary examples of unequal rights being granted to groups of people. Examples abound of discrimination against people of certain ethnicities, races, religious beliefs, sexual orientations, income levels, genders, and more. Social justice requires such characteristics and qualities have no bearing on rights and opportunities. Let's take a look at each of the "types" of opportunities indicated in the definition above.
Please keep in mind that social justice requires equal access to these rights and opportunities. If someone has access to a good education but does not take advantage of it, that is on them. But if they do not have access to it in the first place (e.g., by college being too expensive or public schools in low-income areas being underfunded), that would be considered social injustice. Conceptually, this is straightforward, but practically speaking it can be difficult to determine where injustices occur because the lines between having opportunities and taking advantage of the opportunities is not always clear.
Environmental justice is very closely related to social justice. It is the notion that everyone should have equal rights and opportunities to access a reasonably clean environment. Things like clean air, a safe water supply, and natural areas to enjoy are not available to all. In short, environmental "goods" and "bads" are unevenly distributed. The short video below does a great job of illustrating this phenomenon.
You may have caught the narrator's definition of environmental justice:
A fair distribution of environmental benefits and burdens across all groups.
This sums it up quite well, though it does leave the door open for some wiggle room in what it specifically means. Take another look at the definition. Do you see anything that might be open to interpretation? How about the word "fair"? This is most definitely open to interpretation, but perhaps that is done on purpose. Similar to the economic aspect of social justice, it is not reasonable to think that everyone will have equal access to all environmental goods and equal exposure to all environmental bads. But what we can strive for is to try to provide equal opportunities to access for as many people as possible.
You would think that establishing societies that provide equal rights and opportunities to all would not be controversial. The thing about it - this is is widely considered one of the (if not the primary) core values of American society. Yet, social and environmental justice are often some of the most controversial aspects of sustainability. Though there are, unfortunately, many that do not believe that everyone should have equal rights, more often the controversy arises as a result of the application of solutions to social and environmental injustice. There are many reasons for this, but some important ones are as follows:
The goal of those concerned with social/environmental justice is to provide equal opportunity for all people, and there is wide recognition that many people are born at a disadvantage through no fault of their own. In general, social justice advocates err on the side of providing extra assistance and/or helping empower all who might need help, regardless of how they got into their circumstance. We live in a VERY unequal world, and those concerned with social justice want to change that.
By now you should be able to:
You have reached the end of Lesson 2! Double-check the to-do list on the Lesson 2 Overview page [63] to make sure you have completed all of the activities listed there before you begin Lesson 3.
The purpose of this lesson is for you to review key concepts from Lesson 3 (Critical Thinking and Specific Sustainability Issues) in EM SC 240N. I strongly encourage you to at least browse through Lesson 3 [64] of EM SC 240N, though that is not required.
By the end of this lesson, you should be able to:
To Read | Lesson 3 Online Content | You're here! |
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To Do |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
There has never been a time in human history where such a massive quantity of information is readily available to most people, but the ease with which information can be shared has led to an abundance of questionable information. As the adage goes, "You can always find someone that agrees with you on the Internet" (okay, maybe that's not an actual adage, but you have to admit it is difficult to disagree with it.) At any rate, enter critical thinking, an essential skill to have in our modern information-overloaded world.
Feel free to read through The Foundation for Critical Thinking [65]'s definition of critical thinking (here) [66]. The summary is as follows:
They also provide a good approach to critical thinking:
A well cultivated critical thinker:
- raises vital questions and problems, formulating them clearly and precisely;
- gathers and assesses relevant information, using abstract ideas to interpret it effectively;
- comes to well-reasoned conclusions and solutions, testing them against relevant criteria and standards;
- thinks open mindedly within alternative systems of thought, recognizing and assessing, as need be, their assumptions, implications, and practical consequences; and
- communicates effectively with others in figuring out solutions to complex problems.
Credit: The Foundation for Critical Thinking [66]
I am asking you to apply these principles as much as possible. Keep an open mind, and try to analyze information using evidence, logic, reason, and with an eye on alternative viewpoints. Try to recognize the limitations of your knowledge, and attempt to be self-critical with regards to biases and limited worldviews that you have. Embrace discussion with others, and try to approach discussions with the intent of learning from each other to come to a reasonable conclusion, not to convince the other person that you are correct.
In addition to critical thinking, assessing the quality of sources of information is an important part of determining whether or not the information is reliable. Though there is no universal method of doing this, with some practice (and knowledge) you can usually determine source validity with relative confidence.
Here are some general and additional tips for analyzing sources:
When analyzing sources in this course, I'll ask you to do the following things:
Overall, understanding the reliability of sources gets easier with time. The keys are a) to keep reading and paying attention to other information sources, b) to constantly investigate the reliability of sources, and most importantly c) learn as much as you can! The more you do this, the more you will develop a "bias detector," so to speak.
The following is a summary of some key points from the readings:
"any positive benefit that wildlife or ecosystems provide to people."
Examples include plants that convert carbon dioxide into oxygen, fisheries that naturally replenish themselves and feed humans, wetlands that filter toxins and mitigate storm impacts, soil organisms that foster plant growth, and bees that pollinate food crops and other plants. We could cite innumerable examples, but without ecosystem services, life on earth would not be possible. Further, much of what we depend on for survival is offered for free by nature. Most ecosystem services are performed by the biosphere, which "includes all living organisms on earth, together with the dead organic matter produced by them." (Credit: Encyclopedia of Earth [74]).
The time that we find ourselves in now is what he terms the "Anthropocene," which he defines as "the age in which human actions are a powerful planetary force shaping the biosphere."
So where does the term Anthropocene come from? You may remember the concept of the geologic time scale [77] from Geology or Environmental Science class, which is how the earth's history is separated into different time periods called eons, eras, periods, epochs, and ages. (Refer to this chart from the Geological Society of America [78] for details.)
The Holocene epoch began around 10,000 years ago and saw the beginning of agriculture and thus permanent human settlements. The term "Anthropocene" is a deliberate reference to the fact that humans have become such a dominant force in the world that many scientists consider it to be a new geologic epoch. "Anthro" refers to "humans" (remember anthropocentric from an earlier lesson?), which is why it is referred to as the Anthropocene.
The American Museum of Natural History in New York defines biodiversity thus:
The term biodiversity (from 'biological diversity') refers to the variety of life on Earth at all its levels, from genes to ecosystems, and can encompass the evolutionary, ecological, and cultural processes that sustain life. Biodiversity includes not only species we consider rare, threatened, or endangered, but also every living thing — from humans to organisms we know little about, such as microbes, fungi, and invertebrates.
Credit: U.S. Museum of Natural History [79]
Biodiversity is the variety of life on earth, encompassing everything from the largest ecosystem to strands of DNA. It is in every living thing around us, and everything around us is part of it. I know, this all seems very poetic, and nature can be appreciated merely by virtue of its own beauty and diversity. But there are some practical, and even selfish reasons to care about biodiversity, as you will see in the readings below.
There are many reasons to care about biodiversity. Aside from the huge economic benefits of ecosystem services, we depend on the biosphere - and by extension, biodiversity - to sustain human life. We depend on ecosystem services for food, shelter, clothing, water, and even our oxygen. So yeah, basically everything we need to physically survive!
Life on earth is connected in innumerable ways, and compromising one part of an ecosystem - including a single organism - has impacts in other areas. Unfortunately, human activity is playing a major role in ecosystem damage, including species extinction. Wilson points out [82] that:
"Species are disappearing at an accelerating rate through human action, primarily habitat destruction but also pollution and the introduction of exotic species into residual natural environments."
Biodiversity is a key aspect of ecosystem services, and ecosystem services are essential for human survival. One thing that makes biodiversity difficult to manage is that we don't know how many species exist, and by extension do not know exactly how many are going extinct each year.
So how much danger are we in, and how do we know? As it turns out, it is possible to measure - or at least scientifically estimate - the rate at which biodiversity is dropping. As Carl Folke pointed out in Chapter 2 of Is Sustainability Still Possible?, the rate of biodiversity loss as one of "The Nine Planetary Boundaries." The metric used to quantify this loss is the background extinction rate, which is defined as the number of species going extinct every year. So, how are we doing on this front? Some recently published studies can shed some light on this issue.
Sutter starts out by stating: "Many scientists say it's abundantly clear that Earth is entering its sixth mass-extinction event, meaning three-quarters of all species could disappear in the coming centuries." A mass extinction event is when more than 50% of the world's species disappear in a relatively short period of time (hundreds to thousands of years), according to National Geographic [86]. There have been five mass extinction events in earth's history. The last one was around 65 million years ago when the last of the dinosaurs famously went extinct.
It's not every day that you read a serious article that quotes a knowledgeable person as stating that: "What is at stake is really the state of humanity." Alas, that is where we find ourselves on this issue. There is unequivocal evidence that populations of many species have dropped considerably since humans became the dominant species, and as the article states, the background extinction rate is probably at least "100 times what would be considered normal" (see the optional reading above for some insight on this), which may be a conservative estimate. As indicated in the article, there is some controversy regarding this issue - the Atlantic article [87] that Sutter links to provides a good, even-keeled assessment of some of them - but this primarily has to do with difficulty in determining the rate of extinction, and whether or not it should be considered a "mass extinction" or just a dangerous level of it.
Whether a true mass extinction event is happening or not, we do know that humans are causing species to go extinct at an accelerated rate for a variety of reasons, including land use change (especially food production), poaching, climate change, ocean acidification, and more. It is important to point out that it is very unlikely that we have crossed an extinction threshold from which we cannot recover, but many signs point to us risking catastrophe. There is hope, but we will likely have to take action very quickly to prevent the worst outcome(s). Before this happens, it will have to be recognized as a problem, which unfortunately is only happening very slowly.
Read through the following statements/questions. You should be able to answer all of these after reading through the content on this page. I suggest writing or typing out your answers, but if nothing else, say them out loud to yourself.
First, a few important terms:
The following article from the U.S. National Aeronautics and Space Administration (NASA) explains a lot of the basics regarding the terms listed above.
The greenhouse effect is a universally accepted natural phenomenon, and carbon dioxide (CO2) is one of the primary greenhouse gases. Without it, life on earth would not be possible. The video below from NASA does the best job of succinctly explaining the greenhouse effect of any video I've found. It is not the most high-tech video out there, but don't let that distract you from the content. (For those of you who have been around long enough to remember a teacher popping a tape into a VCR player connected to one of those big CRT televisions, this may spark some memories.)
In a nutshell:
The following gases contribute to the greenhouse effect: water vapor (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and chlorofluorocarbons (CFCs). There are a lot of details about each, but the main focus of anthropocentric climate change is carbon dioxide and methane because they play the largest role in the climate impact that most scientists believe humans are having.
Note that methane is considered approximately 30 times as powerful [89] as carbon dioxide in terms of causing increased warming (over a 100 year period). Methane is the primary component of natural gas and is what gives natural gas its energy. If natural gas is burned, it releases about half as much CO2 as if you burn an equivalent amount of coal. But if natural gas leaks or is otherwise emitted, it is about 30 times more potent than carbon dioxide. Despite this, carbon dioxide reduction is the main focus because it is far and away the biggest contributor to anthropogenic greenhouse gas emissions impact.
There are a few fundamental things to know in regards to the carbon dioxide content of the atmosphere.
We have been directly measuring the atmospheric concentration of CO2 since 1958 in the Mauna Loa Observatory [91] in Hawaii, and have seen it increase steadily since then (see Figure 3.1 below). This is known as the Keeling curve and is named after Andrew Keeling, who initiated the measurements.
We also know with a very high level of certainty the concentration of the ancient atmosphere through time, as well through proxy measures such as ice core samples from ancient ice (click here for some links to explanations of how this is done [92] by clicking on the CO2 Past at the top of the page). The current levels of CO2 are almost certainly unprecedented in the past 800,000 years (credit: National Academy of Sciences) [93]. The chart below depicts the carbon dioxide levels in the atmosphere for the past 400,000 years.
It is an established fact that the burning of fossil fuels releases carbon dioxide and that the concentration of carbon dioxide has been increasing rapidly since around the beginning of the Industrial Revolution in the late 1700s. The Industrial Revolution is characterized by the increased use of fossil fuels - first coal, then oil, then natural gas. All of these non-renewable energy sources release CO2 when burned, and aside from minor natural occurrences like volcanic eruptions, are what has primarily caused the increased carbon dioxide concentration over the past 200+ years.
In short, energy is the primary culprit in anthropogenic greenhouse gas emissions. In fact, according to the International Energy Agency, two-thirds of global anthropogenic greenhouse gas emissions are due to energy use and production (Credit: IEA, "Energy and Climate Change [95]," World Energy Outlook 2015). This boils down to the fact that we are emitting carbon dioxide and other greenhouse gases at rates faster than can naturally be absorbed. This causes an imbalance, and thus the concentration increases.
It is not unusual to hear something like the following as a reason to be skeptical of anthropogenic climate change: "The earth naturally emits WAY more CO2 than humans do. The emissions are so relatively small that they cannot have an impact on CO2 concentrations, never mind climate change."
The earth does, in fact, emit significantly more CO2 than humans do! The image below is from the Intergovernmental Panel on Climate Change's (IPCC) most recent report, called the Fifth Assessment Report or simply AR5. This is an illustration of the global carbon cycle. Carbon, like most other elements, is constantly moving around the earth, e.g., being emitted and absorbed by oceans, being taken up by plants, being released by decaying plants, being released by volcanoes, etc. The carbon cycle illustrates this process. (Don't worry about analyzing this image if you don't want to - it's pretty dense, and you do not need to know any of the numbers.)
This is a pretty busy image, so I'll summarize it for you:
Hmm, okay, so there are way more natural than anthropogenic emissions. So why care so much about the measly 9 billion anthropogenic tonnes? As it turns out, if there were no anthropogenic emissions, the carbon cycle would likely even out, or perhaps even cause a reduction in carbon in the atmosphere. There are many natural processes that absorb carbon, mostly oceans, and vegetation. According to the IPCC, the total increase in carbon in the atmosphere is only about 4 Gt per year (including anthropogenic emissions). If you do a little math it becomes apparent: if that 9 Gt of emissions caused by humans were not there, then there would likely be no increase in overall concentration. Even though the relative contribution is small, anthropogenic emissions throw the global carbon cycle out of whack.
One good analogy of this process is weight gain. Let's say you average around 2,000 calories of food intake each day, and on average you burn off the same amount each day. If this continues over time, you will not gain weight. But if you add one extra 100 calorie snack each day, it will throw this balance out of whack. Even though you are only increasing your calorie intake by a measly 5%, over time this will cause weight gain. Well, it appears that the earth has put on some serious carbon weight in the past ~200 years, and it is almost entirely due to the extra human emissions!
Humans have been taking direct temperature measurements since about 1880. There has been an upward trend in global temperature since around 1900, and the increase has become very sharp since about 1980.
According to NASA [99]:
"Seventeen of the hottest 18 warmest years in the 136-year record all have occurred since 2001, with the exception of 1998. The year 2016 ranks as the warmest on record."
Based on this evidence (which has been corroborated by other scientific sources) and Figure 3.4 above, it is clear that the global temperature has been increasing since humans have been measuring it on a global scale, and it appears that the warming is accelerating.
One note of caution: The earth operates in cycles of thousands and millions of years, so less than 150 years of warming is not undeniable evidence that the climate will continue to warm. However, the correlation that is observed between increased CO2 levels and temperature, along with what we know about GHGs, is troubling.
There is wide consensus that if the climate continues to change and CO2 levels continue to rise the results will not be good (okay, "not good" is a pretty big understatement). As the Intergovernmental Panel on Climate Change (IPCC) stated in their 2007 report: "Taken as a whole, the range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time" (Credit: IPCC, quoted by NASA [100]). This is a stuffy way of saying that "things will probably be really bad and continue to get worse."
The link below outlines some of the possible impacts, some of which have already begun to occur. Note that I am not saying that all of these things will happen, even if climate change continues, but it is meant as a survey of some of the most commonly cited negative impacts of climate change. Also note that some of the likely consequences may be positive in some areas, including extended growing seasons in cool climate zones and some increased growth of plants due to extra carbon being available, but the overall impact will very likely be overwhelmingly negative.
It is also very important to note that the most vulnerable to these impacts will be low-income and otherwise marginalized people all over the world. As the IPCC states in their 2014 assessment:
"(Climate change) risks are unevenly distributed and are generally greater for disadvantaged people and communities in countries at all levels of development" (IPCC, Climate Change 2014 Syntheses Report [102], p. 13).
Translation: the people with little power and/or resources will be disproportionately affected by climate change, regardless of whether they live in a low- or high-income country. This is thus an important social and environmental justice issue!
Multiple reports in peer-reviewed journals have found that at least 97% of scientists actively publishing in the climate field agree that the climate change observed in the past century is likely due to human influence, i.e., it is anthropogenic. See these links to some studies [103]. In 2015, 24 of Britain's top "Learned Societies" - groups of scientific experts, basically - wrote a letter [104] urging that we need to establish a "zero-carbon world" early in the second half of the 21st century. In the past 15 years, 18 U.S. scientific associations [103] have confirmed that climate change is likely being caused by humans. Big players in the private sector are concerned as well. For example, CEOs from 43 companies in various sectors (with over $1.2 trillion of revenue in 2014) signed an open lette [105]r urging action in April of 2015. Even Exxon Mobil states as their official position [106] on climate change (as of the summer of 2018) that:
"The risk of climate change is clear and the risk warrants action. Increasing carbon emissions in the atmosphere are having a warming effect. There is a broad scientific and policy consensus that action must be taken to further quantify and assess the risks."
Exxon Mobil, the world's largest publicly traded oil and gas company, is not known to be a friend of carbon reduction advocates. In fact, a study published in August of 2017 [107] found that they systematically misled the public for nearly 40 years about the dangers of climate change, even though they acknowledged the risks internally. Yet even they assert that emissions should be reduced.
Let's consider these facts together:
These three facts alone indicate that there is likely a problem. But, on top of this, you add that:
Even if we are not certain that humans are impacting the climate (we can never by 100% certain because we only have one planet to run this global "experiment" on), it is probably worth taking the precaution to prevent it if it is true. Yes, it is possible that so many climate experts are wrong - it is a rare occurrence that so many experts are wrong, but there is a possibility, however slim. And yes, we do not know for a fact that humans impact the climate, though basically all signs point to it being the case. And yes, there will be costs associated with making the change to a low-carbon society. But why do people buy life insurance? What about fire insurance? As silly as it sounds, what about buying an extended warranty on a new piece of electronics, or extra insurance for a rental car? The point is that even though the likelihood of using those insurances is minimal - probably less than the likelihood that climate change is caused by humans - people are willing to pay the cost in order to avoid catastrophe. The same could be said of climate change. Taking steps to avoid the worst-case scenario, or perhaps something near the worst-case scenario, is known as the precautionary principle. This may cost money or other resources in the short term, but is seen as worth it because of the situation it may prevent.
One quick addendum to this: If steps are successfully taken to reduce climate emissions to a sustainable level, it is very likely that there will also be cleaner air, less environmental damage, more energy security (not being dependent on another country for energy), and probably more active/healthy citizens. Something to think about.
If you are interested in reading more about this topic, here are some suggested readings.
Now that you have completed the content, I suggest going through the Learning Objectives Self-Check list at the top of the page.
I'm sure I don't need to tell you that water is essential for life, including humans. The earth is considered a "Goldilocks" planet (not too hot, not too cold) based on the fact that water can exist in a liquid state over much of the planet. All water on earth cycles in and out of this system at different time scales (see the figure above), and has been for millennia. In fact, the water that you used to brush your teeth this morning may have been part of the iceberg that sank the Titanic, ran through ancient Roman aqueducts, or was used to wash the makeup off of Cleopatra's face. This is important to understand, because the water we have now is all of the water we'll ever have. There is no shortage of water, but freshwater is limited. The earth naturally replenishes fresh, clean water, but at a limited rate, and there are many obvious indicators that humans are not using freshwater at a sustainable rate.
The following are a number of facts presented by the World Health Organization in their article "Drinking Water [113]." You are welcome to read through the article, but that is not necessary.
- In 2015, 71% of the global population (5.2 billion people) used a safely managed drinking-water service – that is, one located on premises, available when needed, and free from contamination.
- 89% of the global population (6.5 billion people) used at least a basic service. A basic service is an improved drinking-water source within a round trip of 30 minutes to collect water.
- 844 million people lack even a basic drinking-water service, including 159 million people who are dependent on surface water.
- Globally, at least 2 billion people use a drinking water source contaminated with faeces.
- Contaminated water can transmit diseases such diarrhoea, cholera, dysentery, typhoid, and polio. Contaminated drinking water is estimated to cause 502 000 diarrhoeal deaths each year.
- By 2025, half of the world’s population will be living in water-stressed areas.
- In low- and middle-income countries, 38% of health care facilities lack an improved water source, 19% do not have improved sanitation, and 35% lack water and soap for handwashing...
- Contaminated water and poor sanitation are linked to transmission of diseases such as cholera, diarrhoea, dysentery, hepatitis A, typhoid, and polio. Absent, inadequate, or inappropriately managed water and sanitation services expose individuals to preventable health risks...
- Some 842 000 people are estimated to die each year from diarrhoea as a result of unsafe drinking-water, sanitation, and hand hygiene. Yet diarrhoea is largely preventable, and the deaths of 361 000 children aged under 5 years could be avoided each year if these risk factors were addressed...
- Diarrhoea is the most widely known disease linked to contaminated food and water but there are other hazards. Almost 240 million people are affected by schistosomiasis – an acute and chronic disease caused by parasitic worms contracted through exposure to infested water...
- Climate change, increasing water scarcity, population growth, demographic changes and urbanization already pose challenges for water supply systems. By 2025, half of the world’s population will be living in water-stressed areas.
The news is not all bad, though - according to the World Economic Forum [114] (WEF) the United Nations' Millennium Development Goal of "halv(ing) the proportion of the world's population without sustainable access to safe water" was met in 2010. However, the article indicates that while the broad goal was met (global percentage), none of the 48 "least developed" countries met the goal. As usual, there is a deficiency in terms of equity with regards to access to clean water, with "low-income, informal or illegal" populations "usually having less access to improved sources of drinking water than other residents."
These and other factors combine to make access to water an essential part of the quality of life. The United Nations has declared access to water and sanitation a human right and thus should be provided to all people equitably. The UN realizes that access is a fundamental component of the ability to live one's life and further that "clean drinking water and sanitation are essential to the realization of all human rights" (Credit: United Nations [115]).
Here are some things to keep in mind about water scarcity, according to the United Nations [117]:
Water scarcity already affects every continent. Around 1.2 billion people, or almost one-fifth of the world's population, live in areas of physical scarcity, and 500 million people are approaching this situation. Another 1.6 billion people, or almost one quarter of the world's population, face economic water shortage (where countries lack the necessary infrastructure to take water from rivers and aquifers).
Water scarcity is among the main problems to be faced by many societies and the World in the XXIst century. Water use has been growing at more than twice the rate of population increase in the last century, and, although there is no global water scarcity as such, an increasing number of regions are chronically short of water.
Water scarcity is both a natural and a human-made phenomenon. There is enough freshwater on the planet for seven billion people but it is distributed unevenly and too much of it is wasted, polluted and unsustainably managed...
- Around 700 million people in 43 countries suffer today from water scarcity.
- By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world's population could be living under water stressed conditions.
- With the existing climate change scenario, almost half the world's population will be living in areas of high water stress by 2030, including between 75 million and 250 million people in Africa. In addition, water scarcity in some arid and semi-arid places will displace between 24 million and 700 million people.
- Sub-Saharan Africa has the largest number of water-stressed countries of any region
Considering that about 97% of the water in the world is salt water, one of the ways that scarcity can be overcome is through desalination. This is being done all over the world, but current desalination technology requires an immense amount of energy [118], can impact local environments in a variety of ways [119], and is quite expensive [118]. Desalination is probably necessary to satisfy the world's energy needs (and likely increasingly so), particularly in arid areas of the world. But as succinctly stated by Scientific American [119]: "Due to its high cost, energy intensiveness and overall ecological footprint, most environmental advocates view desalinization...as a last resort for providing fresh water to needy populations."
It is a common misconception that household water use (taking showers, washing dishes, etc.) is the primary driver of water use in the world, but only about 8% of global freshwater consumption is from domestic uses. Most - about 70% - is used for agriculture, and over 20% is used for industrial purposes (e.g., manufacturing, energy generation).
It turns out that U.S. water consumption follows a similar pattern. The chart below shows the percent of consumption different sectors of use are responsible for. Some interesting things to note:
Keep in mind that not all water use is consumptive. For example, almost all water used in thermoelectric cooling is used for just that - cooling. Most of it ends up either as steam or as warm(er) water downstream of the power plant. Most of the water used for irrigation is consumptive (62%, according to the USGS), in that it ends up being incorporated into the crops. When water moves from one part of the water cycle to another, it can be days (water lasts about 9 days on average in the atmosphere) to thousands of years (e.g., in the ocean) before it moves to another part of the cycle. (Refer to this description of residence time [121] from the National Center for Environmental Research.)
Given that most water in the world is used to grow crops and generate electricity, it follows that most of the water we use is used indirectly. Every time you use something that must be grown as a crop (food, cotton, wood, etc.) or use electricity (assuming it is from a power plant), you contribute to water use. This "hidden" water of everyday products and processes is considered the water footprint. The Water Footprint Network [122] defines water footprint as "the amount of water used to produce each of the goods and services we use" (Credit: Water Footprint Network [123]).
A water footprint - like an ecological footprint - can be calculated for individual products, individual people, or groups of people (communities, cities, countries, etc.). The folks at the Water Footprint Network provide a lot of information about water footprints [124]. Feel free to take a look at the Water Footprint Network's product gallery [125]to see the (often surprising) water footprint of many common items.
By now you should be able to:
You have reached the end of Lesson 3! Double-check the to-do list on the Lesson 3 Overview page [126] to make sure you have completed all of the activities listed there before you begin Lesson 4.
The purpose of this lesson is for you to review key concepts from Lesson 4 (Energy In-Depth) in EM SC 240N. I strongly encourage you to at least browse through Lesson 4 [127] of EM SC 240N, though that is not required.
By the end of this lesson, you should be able to:
To Read | Lesson 4 Online Content | You're here! |
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To Do |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
Okay, now let's tie this all together. Modern society is inextricably tied to the availability of energy, as we explored in Lesson 1. We just went through more than two full lessons outlining a lot of reasons to be concerned about the sustainability of modern society, in terms of the 3E's of sustainability and otherwise. Putting these two broad concepts together begs the question: What is sustainable energy?
At the risk of sounding glib, the short answer is that there is no short answer. You will probably not be surprised to know that there is no single or even "correct" answer, that is to say, an answer that everyone can agree with. This has a lot to do with the fact that a singular definition of sustainability remains elusive, but in addition to that there is a lot of uncertainty with regards to both the long- and short-term impacts of energy use, and even how much energy (non-renewable in particular) is left to harvest. I want to be clear that the analysis that follows is not meant to answer the question once and for all, but to help frame some of the key considerations to make when answering the question. As you'll see, I've divided the analysis into sections for a number of energy sources, and subsections that provide information regarding supply, feasibility, and sustainability impacts.
One last thing you should consider prior to reading through this lesson: No matter what mixture of energy sources/technologies that we decide to use, we cannot continue to emit CO2 like we are for long. As detailed in the previous lesson, the reality of anthropogenic climate change and its negative impacts have near universal agreement among experts. You may have read about a United Nations study in 2018 that asserted that humanity will likely need to cut global emissions by 40% - 50% by 2030 (that's really not long from now!) and would need to be 100% carbon neutral by 2050 in order to prevent the worst impacts of climate change (here is an NPR summary [128] and here is the official "Summary for Policymakers" [129] from the UN). In case you were wondering, global emissions have only increased since the start of the Industrial Revolution (see below). In addition, a report authored by 13 federal agencies [130] in the U.S. found that consequences for the U.S. will be dire if emissions are not significantly reduced. This report was particularly notable because it was released by the Trump Administration, which is no friend to climate regulation. (It was only released because it is mandated by Congress, and was immediately downplayed by the Administration, but still.)
Please keep this in mind as you read through these summaries. There is near consensus that humans must significantly reduce net emissions to near zero by mid-century, or we face a very dire future. No energy solution should be considered sustainable in the long term if it emits any carbon dioxide unless carbon reduction technologies are sufficient to offset these emissions. Right now, it is much cheaper to not emit in the first place than to capture and store them.
As you can see in the chart above from the EIA, there is a range of estimates of how much coal is available, each having a varying level of accuracy. Feel free to review the coal page [135] in EM SC 240N for an explanation of these, but the quantity that is most commonly used to indicate "how much is left" is estimated recoverable reserves. The estimated recoverable reserves [136] are the portion of the demonstrated reserve base that can be realistically recovered, taking into consideration restrictions (e.g., "property rights, land use conflicts, and physical and environmental restrictions"). Consider it a very good scientific estimate of how much we can mine in the foreseeable future. The demonstrated reserve base [137] also includes coal that could conceivably be mined commercially, but other issues (e.g., technological and political) make it unrealistic.
So how much coal is left?
There are many benefits to living in the United States, but having easy to understand energy units is not one of them. We use a mixture of Imperial and English units, with the system usually referred to as U.S. Customary units. Most of the rest of the world uses metric units, which are also considered SI units (Systéme international d'unités). Got all that? Good. (Here is an explanation [138] of how convoluted the non-metric units are if you are so inclined.)
Coal in the U.S. is usually measured in tons, which is a unit I'm sure you have heard of, and likely used, before. A U.S. ton is equivalent to 2,000 pounds. However, to prevent confusion with an Imperial ton, the U.S. ton should be referred to as a short ton. A long ton, on the other hand, weighs 2,240 pounds. Finally, the metric ton, which is also known as the tonne, is equivalent to 1,000 kg, or about 2204.6 lbs. To summarize:
Credit: Encyclopaedia Britannica [139] and U.S. EIA [140]
The following are some facts about the feasibility of continued coal use:
Now the bad news: coal has a lot of negative environmental and social impacts.
Probably the most important sustainability issue with coal is that it is so carbon-intensive. It emits about twice the carbon dioxide per Btu as natural gas and is responsible for more carbon dioxide emissions than any other energy source, and the energy sector is the largest source of carbon dioxide emissions worldwide. [147] There are other concerns, according to the EIA, including mercury pollution and acid rain. While coal companies are generally very careful to replant any vegetation destroyed by mining, it can irrevocably compromise the landscape.
One possible solution to this is carbon capture and sequestration (CCS) [148], which is a process that can capture CO2 and bury it (i.e., sequester it) in underground rock formations. Under ideal circumstances, up to 90% of the carbon dioxide will turn into solid rock and thus not pose a leakage threat. (This is usually what is referred to as "clean coal" technology, though it is notable that only the carbon emissions are reduced in "clean coal" plants. Mining waste and particulates and other emissions still make this a relatively "dirty" source of energy.) While promising, there is some indication [149] that CCS might not be as effective as once hoped. It is only beginning to be demonstrated on a commercial scale [150], and some plants have had major issues [151], so the jury's still out.
In short, coal is a reliable energy source and is generally a relatively cheap source of energy as long as externalities are not included. Coal does provide good-paying blue collar jobs, and the loss of coal industries can be devastating to local towns. If externalities were to be included, the price would undoubtedly increase, especially if the social cost of carbon were included. CCS provides some hope for reducing the carbon dioxide emissions of coal use, but other significant sustainability problems will persist.
Unless you've been hiding under a rock for at least the past 10 years, you have heard about natural gas in the news. If you have heard about it, it was most likely in relation to hydraulic fracturing, or simply "fracking." This is a VERY controversial topic at the moment, and with good reason (as we'll see below). Because of this, you have to be careful where you get your information (good thing you are taking this course!). Our old friend Hank provides a pretty clear and unbiased description of fracking in the video below.
One popular misconception is that fracking has only been around since the early 2000s or so. As Hank explains, this is simply not the case. Hydraulic fracturing has been known to increase the output of gas (and oil!) wells since the mid-1900s. The main innovation that has caused the recent fracking boom is directional drilling (sometimes called horizontal drilling). Until relatively recently, oil and gas wells were generally drilled in a straight line. But directional drilling allows operators to change the direction of the drill bits so that they can trace the path of underground rock layers (which are rarely straight up and down). This allows for significantly more gas output per well and is what mainly facilitated the fracking boom.
Like coal, it is impossible to determine the amount of natural gas reserves available in the U.S. or worldwide. Most of the data you will see are based on "proved reserves," which the EIA defines as "estimated volumes of hydrocarbon resources that analysis of geologic and engineering data demonstrates with reasonable certainty are recoverable under existing economic and operating conditions." (Credit: US EIA [153]). Basically, proved reserves are a reasonable estimate of the amount of natural gas that is believed to be in the ground that can be recovered given current technology, and for a profit.
Because the proved reserves are based partially on technology, as technology has advanced - especially with fracking - the proved reserves have generally increased. This is clear in the chart below. The upward trend in available gas would seem odd to the uninitiated since it is a finite resource. But it's important to keep in mind that the chart reflects proved reserves, not the actual amount in the ground.
I'm sure you noticed the dramatic drop in proved reserves from 2011 to 2012 and 2014 to 2015. 2015 has a somewhat simple explanation. The price of natural gas dropped significantly from 2014 to 2015, which "(caused) operators to revise their reserves downward", according to the EIA [156].
In the chart above, shale gas refers to gas that is locked up in the pores of shale in underground layers, as described in the fracking video above. Tight gas refers to gas that is locked up in other formations like low-permeability sandstone. For a full explanation of the terms, see this EIA website [158].
So how much gas do we have left? The EIA provides the following analysis and explanation [159]:
At the rate of U.S. natural gas consumption in 2016 of about 27.5 Tcf per year, the United States has enough natural gas to last about 90 years. The actual number of years will depend on the amount of natural gas consumed each year, natural gas imports and exports, and additions to natural gas reserves.
Like coal, the natural gas infrastructure is well-established, including wells, pipelines, and power plants. As you saw previously, natural gas is relatively cheap. The recent boom in natural gas production has provided a lot of high-paying relatively low-skilled jobs and has generated millions of dollars in royalties for landowners. Increased use and cheaper (up front) cost of natural gas has allowed the widespread replacement of coal-fired power plants, which has resulted in natural gas increasing its share of U.S. electricity production from 18% in 2005 to 32% in 2015. During the same period, coal's share has dropped from 51% to 34%. This is a major change in just over a decade!
One major benefit of this is that it has contributed to reduced CO2 emissions that come from electricity generation in the U.S. These emissions are at their lowest level since 1993. The EIA explains that: "A shift in the electricity generation mix, with generation from natural gas and renewables displacing coal-fired power, drove the reductions in (CO2) emissions." This is a major benefit of natural gas. As indicated previously, burning natural gas results in approximately half of the emissions from an equal amount of coal energy.
But this is not the whole story regarding emissions. Remember that while natural gas emits about half of the CO2 as an equivalent amount of coal when burned, natural gas itself is about 30 times as powerful as carbon dioxide in terms of greenhouse effect impact over a 100 year period and about 80 times as powerful over a 20 year period. One result of this is that methane leaks throughout the natural gas supply chain (from the well to the end user) counteract some of the positive impacts of natural gas being a relatively clean-burning fuel.
Some other considerations regarding natural gas, mostly from this article by John Wihbey [164] include:
In short, natural gas is really a mixed bag of sustainability implications, especially with regards to hydraulic fracturing. The primary benefits from a sustainability perspective are that there is no doubt that it has reduced CO2 emissions, but to what extent natural gas leaks have counteracted that is in question; and also that it has created an economic boom, at least in the short term. There are many downsides, particularly with regards to environmental damage (water, air, land), but also with regards to quality of life for some people near wells.
In terms of feasibility, oil is so ingrained in modern society and its infrastructure is so well-established that there is no risk of not being able to integrate oil supplies into the economy and society. However, oil supply projections have a very interesting history, and like the price, projections of supply have been volatile. First of all, like natural gas, the calculation of proved reserves is subject to limitations of using current technology, economics, and known reserves, each of which can change from year to year. Like natural gas, for oil, proved reserves refer to "those quantities of petroleum which, by analysis of geological and engineering data, can be estimated with a high degree of confidence to be commercially recoverable from a given date forward, from known reservoirs and under current economic conditions" (Credit: CIA Factbook [166]). The result (again, like natural gas) is that even though oil use is increasing globally every year, there are paradoxically more proved reserves. Please note that the chart below represents global proved reserves.
How is it possible that we can continue to use more oil each year, yet the estimated remaining supplies keep increasing? The primary reason is improving technology. We have so far been able to exploit new resources as the market demands more oil. The most recent increase in proved reserves, especially in the U.S., is from shale oil that can be extracted through hydraulic fracturing (aka fracking). There has been an oil boom that has come in lock-step with the recent natural gas boom, all due to fracking. Access to additional "unconventional" reserves via tar sands in Canada has also contributed to the increase in proved reserves and supply.
Dr. James Conca provides a very good explanation of the somewhat complex workings of the global oil market in the article below. As you will see, the price of oil and the economic feasibility of technology is not as simple as supply and demand. He also throws in a nice lesson on how fossil fuels are formed for good measure. Also, if, like me, you have found yourself wondering whether oil deposits are more like a jelly donut or tiramisu, he'll help you out with that as well.
There are a few important things to point out from this article:
So, how much oil is left, and how long will it last?
There are many sustainability considerations when it comes to oil. The following are some of the sustainability benefits:
However, there are of course drawbacks, including the following:
Oil is an extremely useful resource, and it is a very important aspect of the modern economy, and by extension, society. Considering that current projections assert that we only have about 50 years of supplies left, we should probably try to maintain our resources for as long as possible, and avoid an abrupt collapse. But we also should be conscious of the sustainability impacts of its extraction and use.
Nuclear energy has been a hot-button issue for a very long time, both domestically and internationally. It provides a significant portion of the global electricity supply, as you will see in the image below.
Nuclear energy is non-renewable. Uranium is by far the most-used nuclear fuel. As with other non-renewable fuels, all of the uranium that is on earth now is all that we will ever have, and estimates can be made of the remaining recoverable resources. At current rates of consumption, we will not run out of uranium any time soon. But this depends very highly on a number of variables, including keeping consumption at current levels, technology not advancing, estimates of reserves changing, and so forth.
The World Nuclear Association (WNA), an industry association, provides a very thorough explanation of possible complicating factors [183], but they state that at current rates of consumption, the world has enough reserves to last about 90 years. The Nuclear Energy Agency (NEA [184]), like the WNA, [184]is effectively an industry group and has a wealth of expertise at its disposal. They indicate that as of 2009, the world had about a 100 year supply of uranium. So it appears that as long as the rate of use does not increase there is a little less than 100 years of nuclear fuel supplies left.
According to the World Nuclear Association, there are 454 operable reactors worldwide with a further 54 under construction [185]. The technology is well known by now, and despite the extreme danger posed by nuclear meltdowns, there have been very few major incidents. You are probably familiar with the Fukushima Daichi meltdown that happened in 2011, and perhaps heard of Chernobyl in Ukraine in 1986 (still the worst nuclear disaster to date), and maybe even Three Mile Island in the U.S. in 1978. Here is a partial list of nuclear accidents [186] in history from the Union of Concerned Scientists (UCS). But putting aside this risk at the moment, nuclear energy has shown itself to be a viable source of electricity, and likely will continue to be used for the foreseeable future. Among other things, nuclear power plants generally have a useful lifetime of around 40-60 years, so we are "locked in" until mid-century at least.
Nuclear energy is a mixed bag in terms of the question of sustainability. You may recall that nuclear is considered a carbon-free source, and since it is a proven and reliable source, it is seen by many as a good option. Note that despite being considered "carbon-free," nuclear energy results in some lifecycle emissions because of the materials used in mining, building the power plant, and so forth. (Lifecycle emissions are all the emissions generated by all processes required to make an energy source, including things like mining of materials, manufacturing of equipment, and operating equipment.) But according to the National Renewable Energy Laboratory (NREL) [187] it has approximately the same lifecycle emissions as some renewable energy sources.
Some other sustainability considerations include:
The first article below is a good example of why it pays to pay attention to citations and be well informed on a topic, in regards to finding good information sources. The article is on a website that I've never heard of before, so at first, I was suspicious of the content. However, they provide legitimate sources for the information presented, and I have enough prior knowledge to know that the arguments they put forth are legitimate. Overall, it's a good summary of some of the pros and cons of nuclear energy.
Overall, nuclear is reliable and almost carbon-free but is expensive and non-renewable. Also, because power plants are so expensive to build, once they are built they are generally used for as long as possible, as long as they are still economic. When accidents happen, they can be catastrophic, but they are extremely rare. However, the waste product from nuclear power plants is dangerous for thousands of years, and right now we have no way of safely disposing of it - it is kept in storage, usually at the power plants themselves.
The supply aspect is very straightforward for wind and solar: they are inexhaustible! As stated in Lesson 1, both of them get their energy from the sun; and if the sun stops shining, we have more important issues to deal with than not having a source of renewable electricity. The amount of solar energy that hits the earth in one hour is enough to power the world for an entire year (this is a commonly held fact, but here is one source [195]). There is no shortage of solar energy!
As for hydroelectric, though it also gets its energy from the sun, it is limited due to its dependence on the availability of flowing water. As of 2014, about 17% of the world's electricity came from hydroelectricity. According to the International Energy Agency [196], there is about 5 times as much technical potential for hydroelectric worldwide as is currently generated today. We certainly would not want to exploit all of it, given some of the environmental impacts of large hydroelectric facilities (see below), but this number does provide a frame of reference.
The feasibility is a mixed bag.
One sign that bodes well for renewables is that the cost has come down significantly in recent years.
This is all based on the levelized cost of electricity (LCOE), which was noted in the nuclear lesson. The LCOE is the amount it costs to generate each unit of energy (usually measured in $/megawatt-hour) on average over the lifetime of an electricity source. To calculate the LCOE, you take the total lifecycle costs and divide by the total electricity output over the lifetime of the source. This is of course not including externalities, which would likely make renewable energy cheaper right now, especially if the social cost of carbon were to be considered. See the chart below for details. Note that information for utility-scale vs. residential-scale solar was not made available for the U.S., but refer to this chart from Lazard [199] for global data, which also includes residential and utility-scale solar.
Plant Type | Total System LCOE ($/MWh) |
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conventional combined cycle natural gas | 48.3 |
advanced combined cycle natural gas | 48.1 |
advanced combustion turbine natural gas | 79.5 |
advanced nuclear | 90.1 |
geothermal | 43.1 |
biomass | 102.2 |
onshore wind | 48.0 |
offshore wind | 124.6 |
solar PV | 59.1 |
hydroelectric | 73.9 |
The bottom line in terms of cost is that right now, well-sited wind and utility-scale solar are the cheapest form of electricity available, other than only the least expensive natural gas power plants. (Please note that energy efficiency is cheaper than all energy sources!) Other renewable sources such as small hydroelectric, biomass, geothermal, solar thermal, and commercial-scale solar are very cost-competitive with coal and natural gas, and generally less expensive than nuclear. All of this does NOT include subsidies, by the way!
All three of these sources are carbon-free, so they are ideal with regards to anthropogenic climate change. Even after consideration of the embodied energy of these sources, the lifecycle carbon footprint is minimal for renewables, as you can see in the chart below. In terms of climate change concern, there is really no debate: these renewables are great choices.
However, there are some other considerations to make in terms of sustainability. First, large hydroelectric facilities are not very environmentally friendly. Depending on the location, there can be problems with flooding of habitats and even towns, compromising fish migration, altering stream content and temperature, impacting scenic areas, and other considerations. The articles below provide some insight into some of these potential problems. Note also that not all hydro has the same problems - by using different types of hydroelectric facilities such as run-of-river and micro-hydro [204], environmental and social impacts can be minimized.
In terms of social equity, there are a few important considerations to make. First of all, do people have access to energy, and can they afford it? This is a tricky question to answer, as it depends on a lot of factors, many of which were indicated above. Some equity and other considerations include:
One of the benefits of conventional energy generation is that the infrastructure is largely set up, at least in industrialized countries. In the U.S., for over 100 years, we have built an energy infrastructure based on large power plants and fossil-fuel based vehicles. This gives conventional energy sources an advantage in terms of providing access. That said, wind, hydro, and solar can all utilize the existing infrastructure. Hydroelectric dams provide the same service as fossil-fuel power plants, but usually on a slightly smaller scale, so they are a good fit. They also provide a very consistent stream of electricity as long as no droughts are occurring, and they can increase and decrease production pretty rapidly, unlike solar and wind.
Probably the biggest current problem with solar and wind is that they are intermittent - the sun does not always shine, and the wind does not always blow. This is a major issue because we currently do not have the storage capabilities to provide the energy on command. One common problem with wind and solar are that they are often highest in areas with low population densities. In the U.S., for example, the greatest on-shore wind resources are in the Great Plains in the Midwest, where the population density is very low.
One of the benefits of solar is that as long as there is not too much shading, many households can satisfy their energy needs using existing rooftop spaces. However, not every location is ideal for solar. The intermittency of wind and solar is also a major problem, as noted above. This will change if/as battery technology becomes more accessible, and as the grid is upgraded.
Overall, the biggest advantages of renewable energy sources are:
The main disadvantages of solar, wind, and hydro are:
The last thing I'd like to note is that the most sustainable energy is the energy that you don't use. Remember that energy efficiency is sometimes called the "fifth fuel?" That is very much applicable to these considerations. Also, as noted above, energy efficiency has been found to have a lower LCOE than any other energy source! [212] The more we can reduce our energy use while getting the same benefits from the energy service, the better off we will be.
By now you should be able to:
You have reached the end of Lesson 4! Double-check the to-do list on the Lesson 4 Overview page [213] to make sure you have completed all of the activities listed there before you begin Lesson 5.
The purpose of this lesson is for you to review key concepts from Lesson 5 (Rhetorical Analysis) in EM SC 240N. I strongly encourage you to at least browse through Lesson 5 [214] of EM SC 240N, though that is not required.
By the end of this lesson, you should be able to:
To Read | Lesson 5 Online Content | You're here! |
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To Do |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
Please read the following sentences, and think about the message(s) each one is giving you. Imagine that you don't know anything about the person who is making the statements other than what you read. Treat each example separately.
Each of these statements exhibits an attempt to convince you that solar panels are a good idea, but each in a different way. Think about the language devices employed in each of the sentences. What part of your psyche does it attempt to address? Is it logic, emotion, or something else? Are they obvious attempts to gain your agreement, or do they seem reasonable?
Each of these sentences uses a different rhetorical strategy. Rhetorical strategies are the subject of this lesson, specifically the rhetorical triangle. At the root of all of this is rhetoric, so let's start there. This is just a quick video introduction - no need to take any notes or anything like that.
Purdue University's Online Writing Lab [215] (OWL) provides a lot of publicly available resources that are designed to help students and others become better writers. They do not allow embedded videos, so please click on the link below if you'd like to watch.
Rhetoric/rhetorical arguments are designed to convince an audience of whatever the speaker is trying to say, or as Purdue OWL notes, it is "about using language in the most effective way." You most often hear this when referring to a politician, or at least someone acting politically or disingenuously, for example: "That speech was all rhetoric." When you hear or read this phrase, it is meant in a negative way and implies that the speaker was using language to trick the audience into believing the argument they were presenting. As noted in the video above, this negative connotation goes back centuries. But rhetoric has a few connotations, not all of them negative. It can refer to "the art of speaking or writing effectively," and "the study of writing or speaking as a means of communication or persuasion." These two definitions do not necessarily connote deceit. But it can also mean "insincere or grandiloquent language" (Credit: Merriam-Webster [217]).
So, contrary to popular belief, rhetorical arguments are not always "insincere." That said, in this course, we are most concerned about seeing through rhetoric (rhetoric in the negative sense, that is) to evaluate arguments. Please note that rhetorical strategies can also be deployed visually - for example in images, photos, and video - and audibly. Advertisers do this all the time.
Rhetoric is used to persuade people, and there are three general strategies used to do this: ethos, pathos, and logos. Please watch the video as an introduction to these strategies. We will then go into more detail in each in the following lessons.
Purdue University has an excellent online writing lab. It has a lot of very helpful information, including how to use rhetorical strategies.
Ethos, pathos, and logos are rhetorical strategies, but these are not rhetorical devices. Rhetorical devices are specific methods that can be deployed to make a persuasive argument, whereas rhetorical strategies are general strategies. You have likely picked up on many of these devices when listening, reading, or speaking. Politicians are particularly fond of them. The "Mental Floss" website [220] goes over some of them. If you Google around, you will find more.
Two of the previous sources provide concise definitions of ethos:
Purdue provides the following examples of ways that you can establish ethos. I highlighted a few things that are most important to consider:
- Use only credible, reliable sources to build your argument and cite those sources properly.
- Respect the reader by stating the opposing position accurately.
- Establish common ground with your audience. Most of the time, this can be done by acknowledging values and beliefs shared by those on both sides of the argument.
- If appropriate for the assignment, disclose why you are interested in this topic or what personal experiences you have had with the topic.
- Organize your argument in a logical, easy to follow manner. You can use the Toulmin method of logic or a simple pattern such as chronological order, most general to the most detailed example, earliest to the most recent example, etc.
- Proofread the argument. Too many careless grammar mistakes cast doubt on your character as a writer.
Pathosethoslogos provides the following advice:
Ethos can be developed by choosing language that is appropriate for the audience and topic (also means choosing proper level of vocabulary), making yourself sound fair or unbiased, introducing your expertise or pedigree, and by using correct grammar and syntax."
There are many ways to establish ethos (credibility) with your audience. Some of the most common are listed above, but there are others. What it boils down to is that whether you are speaking, writing, or trying to communicate in any way, anything you do to try to convince your audience that you are a credible, reliable source of information, is ethos. Any time that someone is trying to establish credibility, they are using ethos.
Okay, now let's get back to our original examples. Which of these sentences relies the most on ethos, and why do you think so?
If you said the second example, then give yourself a pat on the back. The language used in that narrative is a clear attempt to establish the author's credibility, in a few ways.
Remember, any way that a speaker or writer can establish credibility and believability is ethos. There are myriad ways of doing this, including using appropriate language, citing legitimate sources of information, dressing appropriately, speaking/writing with confidence, avoiding grammatical and/or spelling errors, and more.
So, now that we have ethos figured out, here's a little curveball: Appeals to ethos can change from situation to situation, even if it is the same speaker or writer trying to convey the same message. The video below from our friends at Purdue University does a really good job of explaining this and goes over ethos in general as well.
The narrators sum up ethos nicely by stating that: "In every rhetorical situation, ethos means a quality that makes the speaker believable." This "quality" can and does change all the time. Even if you don't have the credentials that render you credible on the topic, you should do your best to establish credibility by doing things like using reliable sources, proper language, and so forth. You've probably heard the truism that as a speaker or writer you need to "know your audience." Establishing ethos is one of the reasons why. You want your audience to believe you, and ethos can help make that happen. Politicians are particularly (or notoriously, depending on whom you ask) good at doing this. An example of this can be seen below.
Notice the stark difference in physical appearance in the photos of Barack Obama above. What messages is he sending with regards to ethos? The left photo shows the classic "sleeves rolled up" look, which politicians use to speak to "regular folks," usually in public settings like fairs, construction sites (they'll also don a hard hat for this), local restaurants, and so on. The ethos-related messaging is something like: "Hey, I'm just a regular, hard-working guy like you. I understand your problems." But by wearing a dress shirt instead of, say, a polo shirt, an air of authority and professionalism is still presented.
The photo to the right presents a much different attempt at ethos. He is projecting an image of power and authority by wearing a suit and tie, being the only person in the shot, and sitting in a well-appointed office. Even his posture is different than the other photo. Note that both an American flag and flag with the Presidential Seal is in the background. Both project authority, among other things. Do you notice anything else in the background? Do the family pictures convey a message? This is a subtle reminder that he has a family with two young children, and thus is relatable (this is probably also an example of pathos).
It can be easy to view ethos as a way to "trick" audiences into being persuaded by someone. This can certainly happen and often does. This is a common problem with politicians, as they never want to appear not credible. But it is important for you to know that ethos can be legitimately established. Knowing as much as possible about the source of information is an important aspect of determining credibility. For example, if I want to know about drought conditions across the U.S. [225] I refer to the National Oceanic and Atmospheric Administration (NOAA) [226] since I know that monitoring water conditions is one of their focuses and that they are tasked with presenting an unbiased, scientific perspective. In short, I know that they are credible.
If the Administrator of NOAA [227](one had not been confirmed yet [228], as of September 2018) was to give a speech or write an article, (s)he would be remiss if (s)he did not let the audience know her/his position. (S)he has credibility, but still may need to establish ethos. Doing this does not mean that (s)he is trying "trick" anyone, but it does mean that (s)he is trying to strengthen her/his argument, which if you recall is the purpose of rhetoric. Ethos is only established if the audience thinks that you and/or your argument, is credible, and that can be done without being dishonest or "tricky" in any way.
Describe one specific example of something that could establish OR compromise ethos, depending on the audience.
Please watch the commercials below before continuing.
What was your reaction to each of these videos? Was your reaction to each similar in any way? Different? If you have not already, take a moment to think about how each commercial tried to persuade you through its emotional content.
Please click on the link below for an explanation of pathos.
As noted in the video, pathos can be defined as "the emotional quality of the speech or text that makes it persuasive to the audience." Though most often associated with sympathy, sadness or similar "sad" emotions, pathos can utilize the full range of human emotion, including anger, joy (e.g., through laughter or inspiration), frustration, suspicion, curiosity, scorn, repulsion, jealousy, desire, compassion, hope, love, and more.
Please take a few minutes and think about all the ways that the commercials at the top of the page attempt to elicit an emotional response. Do these attempts make the commercials more persuasive? Why or why not?
The McDonald's commercial uses one of advertising's favorite pathos tools - the baby [232]. Babies tend to elicit all kinds of positive emotions - e.g., happiness, sympathy, love, and compassion. When in doubt, find a way to put a baby (or puppy) in your advertisement! (No, seriously. Next time you see some advertisement, see how often a baby or puppy appears.) The commercial also uses humor and (for parents, anyway) empathy. Even the music evokes pathos. Note that the baby is essential to the plot of the commercial, but I submit that (s)he has absolutely nothing to say about whether or not I should eat at McDonald's. Pathos does not need to be logically consistent with the rest of the work. It is meant to play on the audience's emotion(s). This is one thing that distinguishes the first ad from the second.
The second ad uses kind of an odd mixture of suspense, dread, and humor to get its point across. The humorous aspect in and of itself has little connection to the product. (It should be noted that there is some humor in the first commercial as well, e.g., the girl hurriedly sliding over the counter in the middle of it.) However, the negative emotion created by the man's reaction to the cable bill and the woman's to the telemarketer could be said to have a direct connection to the real-life experience of issues related to cable TV. Of course, this is all seriously overdramatized (at least for me, but I suppose everyone reacts to their bills in their own way), but milder versions of the emotions expressed are not far-fetched.
The third ad uses pathos (sympathy, sadness, anger, etc.) to get its point across, but the pathos is very much consistent with the message of the video. Speaking for myself, the imagery used in the third video makes it much more impactful than an article providing statistics about how parents' behavior can negatively impact children. In other words, the pathos served its purpose.
I consider the pathos in the McDonald's ad to be "fake pathos," which was described in the video from Purdue. From my perspective, the McDonald's ad is a clear attempt at emotional manipulation (though I don't think they want the viewer to think that), and thus compromises the ethos of the company because it calls into question their credibility. Call me a cynic, but I don't think that the goal of making the ad was to spread joy and laughter. As the folks from Purdue mentioned, that is the risk you run if your pathos is not genuine. The Sony commercial is overdramatic, but it's so "over the top" that it's quite clear that it is done in jest and (again, speaking for myself) does not compromise ethos. Regardless of how genuine or fake the pathos is, it is still used to create an emotional response. To a large extent, the impact on ethos is subjective.
Pathos is the most commonly used rhetorical strategy in advertising (both print and video) because it is often relatively easy to do with imagery. See below for an interesting example from the World War II era.
Pathos can also be conveyed in writing. As noted in the video, this often boils down to word choice, in particular, adjective choice. In fact, word choice often provides the reader with insight into the motivations of a writer.
The two articles below are about the same issue - the revised "Clean Power Plan [234]" announced by the Obama Administration in August of 2015, which has since been revoked by the Trump Administration. This plan was designed to reduce CO2 emissions from power plants in an effort to "take real action on climate change" by requiring states to meet emissions standards set by the federal government. This would impact some states more than others - states who get a high percentage of their electricity from coal would be particularly impacted. As you can well imagine, this is not without controversy. When reading the articles below, pay special attention to word choices that can elicit emotion, especially when other, more neutral words could have been used. Note that both are from reputable websites, but that both are opinion pieces.
Here is another short article about the Clean Power Plan. See if you can pick up on any use of pathos from the author, or not.
Was pathos used by the author? The only instances of pathos are used to describe what other people are saying - e.g., "slashing jobs," "driving up prices" - the author himself writes dispassionately about the topic. This demonstrates good reporting, using more ethos and logos (see next section) to persuade the audience.
Add and/or change some words from the Time Magazine article to evoke more pathos in the following paragraph. Have some fun with it!:
"In a report released last week, public policy professor Marilyn Brown found that boosting renewable energy sources such as wind and solar power would reduce energy costs in the long run as they become more readily available. Even if energy costs did go up in the short run, she argued that would cause consumers to invest more in things like energy-efficient appliances, which would again lead to lower electricity bills over time."
Please note that I am not advocating one opinion over the other on this topic, nor am I saying that either of the authors is telling untruths. I am merely pointing out word choices that convey pathos. Perceptive readers will pick up on such word choices, which may compromise ethos. Pathos can be an effective persuasive technique, but generally only if the reader agrees with the author's arguments. As critical thinkers, you should be skeptical of anyone that uses pathos in such a way that appears to try and persuade you to believe one thing or another, whether or not you agree with the overall point.
Finally, back to the statements at the beginning of this lesson. Which one is most pathos-filled?
Of course, the last one is the correct choice. The use of children's suffering and in particular the use of the word "innocent" are both meant to elicit pity, and ultimately sympathy. Even if it is true, the statement is unnecessarily emotive. I could have just kept to the facts and stated that said power plant has been shown to cause asthma problems for children. This is a strong reason to be concerned. It is still an example of pathos but does not lay it on quite as thick.
Logos can be thought of as "the logical quality of a speech or text that makes it persuasive" (Credit: Purdue University Online Writing [239]Lab [240]). Often this is straightforward - when you read, hear or see an argument, ask yourself if it makes logical sense. Is the reasoning sound? Does the author make any unfounded conclusions? Is she confusing cause and effect or coincidence with causality? All of these can contribute to, or subtract from, logos.
The folks at the Purdue Online Writing Lab provide a good explanation of logos.
It is very important to note that logos is not necessarily how logical (sound) or accurate (true) the argument is. It is the attempt at logic made by the way the argument is structured. Of course, a sound and true argument is more likely to establish logos, but it depends on the perception of the audience. Examples of how to establish logos include:
In short, anything that appeals to the audience's sense of logic (as opposed to emotion or the author's credibility) is considered logos.
As noted in the reading above, two common ways of doing this are through inductive reasoning and deductive reasoning. Inductive reasoning takes a specific example or examples, then assumes that a generalization can be made based on that example or those examples. In other words, inductive reasoning goes from the specific to the general. The following are examples of inductive reasoning:
Inductive reasoning can be correct or incorrect (the first example above is correct, and the other three are not, by the way) - it is up to the audience to determine whether or not the logic is valid. But inductive reasoning is an attempt at logos, irrespective of its validity. The persuasive effectiveness of logos depends on a myriad of factors and can change from audience to audience. The same goes for deductive reasoning. Deductive reasoning is the application of a general belief, and applying it to a specific example, i.e., it goes from the general to the specific. Some examples of deductive reasoning are below:
Like inductive reasoning, deductive reasoning can be false (neither of the above statements can be verified, but they can certainly be false), even if they are sound. If I've seen hundreds of swans and they have all been white, then assuming that the next swan I will see will be white is sound reasoning based on my experience, but it may be false because there are other colors of swans out there. Again, it is up to the audience to determine whether or not the logic is sound and/or true, but it is an example of logos either way.
As is the case for pathos and ethos, the effectiveness of the rhetorical strategy depends on many factors, and can (in fact, often does) change from audience to audience. With logos, sometimes seemingly sound arguments are neither sound nor true. This is referred to as a logical fallacy. Logical fallacies are encountered all of the time, and you may even use them, accidentally or otherwise. Logical fallacies will undermine your persuasiveness if they are found by the audience, and in turn, impact your ethos as well as your logos. The reading from Purdue linked to previously goes over some of these arguments and provides some examples. There are many possible strategies, sometimes known as "logical appeals," to making a logical argument. Some of them can be seen in the reading below.
Dr. George H. Williams, Associate Professor of English at the University of South Carolina, put together some good examples of logical strategies. Please read the "Logos" section in the reading below.
Given all of this, which of the examples below are the strongest attempt at logos? Do any of the other sentences exhibit logos?
The first sentence is a pretty weak attempt at persuasion. The second example is really just an opinion, with an attempt at ethos. You could say that some attempt was made at logos because the argument is structured in a logical way (self-introduction, demonstrates similarity to you, then offers an opinion). The fourth one is similar in logos to the second one - it has a logical structure - but it is much stronger on pathos. The third example is the strongest. The argument follows a logical flow of statements. Something of an "either/or" argument is presented when the speaker states that "there is no better way to save money and get clean electricity." It's subtle, but inductive and deductive reasoning is used. Because the speaker is happy with their work, it is assumed that everyone will be happy (inductive), including you (deductive).
If you make a true argument with impeccable logic, it will establish logos.
(a) Yes
(b) No
(c) It depends
Watch the video below and see if you pick up on any rhetorical strategies.
So, what did you find?
This commercial is filled with pathos. The babies (are some children?) are meant to evoke happiness/warmth/etc. The song is jaunty and catchy - I don't know about you, but I actually like it. The imagery (other than the "bad" gas stations) is colored with pastels, giving it a very soft look. The BP gas pump is whistling(!) and the kids are smiling after they go to the BP station. There is a small attempt at humor at the end (the "baby" part of "gas stations, a little better, baby"). All of this is pathos.
The only thing I could detect was at the end when BP put its brand on the screen "Beyond Petroleum." This is a weak attempt at establishing credibility, and I imagine not purposeful. They do that at the end of every commercial. There is no scientific information or even scientific-sounding information. No people in lab coats or statistics cited. Really, very little in the way of ethos.
There is not much in the way of logos either. The story does have a logical progression - happy kids run out of gas, pass gas stations with inferior gas, kids refuse the "bad" gas, then find a BP station and end up happy and high-fiving. I know, this story is ridiculous on its face, but it does tell a story with some logic to the structure. BP is also saying that their gas is better, or at least a little better. You could also say that showing wind turbines at the end of the commercial is an attempt to associate renewable energy with BP, so perhaps the audience might think that BP supports wind turbines. This is a bit of a logical leap but could be considered logos.
There are a number of rhetorical strategies being deployed in this commercial, which to be honest, is to be expected. Please note that this is not meant to single out BP - as noted earlier in this lesson, print and video advertising is rife with rhetoric, pathos in particular. But is there anything that does not quite "sit right" with you when watching the video? Does it feel like part of the story is missing? Anything odd about an oil company using so much green imagery?
This article provides a good introduction to what greenwashing is and how to spot it. Please read before continuing.
Greenwashing can be thought of as:
So, why would a company spend the time and money to convey a green image, and risk being viewed as insincere? As you might have guessed, it's good for business. Investopedia notes that: "The general idea behind greenwashing is to create a benefit by appearing to be a green company, whether that benefit comes in the form of a higher stock price, more customers or favored partnerships with green organizations."
Being (or at least putting on the appearance of being) "green" or sustainable has become a very good marketing strategy. Think about all of the times you've seen the term "green" or "sustainable" associated with a product or process. It is happening in basically all sectors of the economy - food, energy, transportation, housing, business, cleaning products, events, sports stadiums, and even fashion. Business pursuing sustainability is not a bad thing. If we are going to achieve a sustainable future, the business community will have to be on board, if not leading the way. The problem is when a business is using sustainability more as a marketing ploy than a legitimate attempt at addressing sustainability.
So, how do you know if a company is making a legitimate attempt at addressing sustainability? In short: it's complicated. The folks in the Greenwashing Index offer some good suggestions on how to investigate claims (see the "How Do I Spot It?" section in the reading):
The best way to fight greenwashing is to become educated about sustainability and take the time to learn about companies.
The video below illustrates some facts about BP that could be found with a little research.
Even though BP is not directly making any claims other than being "a little better," the rhetorical strategies outlined above are used to indicate the company's "green-ness." To be fair, BP has been one of the more aggressive oil companies in regards to renewables. According to Bloomberg Business [245], they achieved their goal of investing $8 billion in renewables between 2005 and 2015. They heavily invested in wind farms, though they have recently put many of them up for sale. They had a solar division for decades, and only recently shut it down. They are still fairly heavily invested in biofuels. Whether or not it's wise for BP to invest in renewable energy may be debatable [246], but the point is that renewables are a tiny sliver of their business, so focusing marketing on that aspect is greenwashing.
You may be thinking "What are they supposed to do - advertise the negative climate change implications of their business?" That would be a fair question. But it is possible to be a little more reasonable in the message the company sends. If they oversell their "greenness," it is greenwashing.
This article from the Worldwatch Institute provides some examples of greenwashing, and some tips for how to avoid it.
Greenwashing is not only used by energy companies. Watch the ad below and see if you can pick up on any rhetorical strategies, and think about whether or not it is greenwashing (hint: think about what you know of the electricity industry from Lesson 1).
Okay, one more example. Once again, keep an eye out for rhetorical strategies.
You probably figured out that this last one is a parody (a pretty funny one, if you ask me). But it actually makes some really good points by bringing light to the touchstones that many advertisers put in their commercials to persuade you. Again, this is not meant to single out the petroleum and plastic industries, as these techniques are used by many companies. But it is the only parody video I know of.
Again, the best way to detect greenwashing is to learn as much as possible about sustainability and to research companies' claims. The best way to reduce the incidence of greenwashing is for consumers to push back against companies that do it. By "voting with your dollars" you hurt profits, which is a good way to get a company's attention.
Hopefully, it's pretty clear what greenwashing is, and how to spot it. But why does it matter? Of course, advertisers are not telling us the whole truth, and are just trying to get us to buy their products. After all, that is literally their job (the part about getting us to buy their stuff is, anyway). The main problem with greenwashing is that it can trick people into doing things that they think is promoting sustainability, but it is actually not, or worse - it is promoting things that are bad for sustainability.
Most often, the best way to address sustainability is to not buy anything at all. But given that it's nearly impossible to go through life without buying things and that consumer spending constitutes somewhere around 70% of U.S. GDP [248], making wise consumer choices is important. Greenwashing makes this much more difficult.
Why would a company risk being viewed as one that greenwashes?
Hopefully, by now you see that there are a number of rhetorical strategies available to help convince people of an argument. Though this can be seen as manipulative in many cases, often times it does not involve actual lying. But what is lying, exactly? Merriam Webster's online dictionary [250] provides two relevant definitions of a lie:
lie (intransitive verb)
- to make an untrue statement with intent to deceive
- to create a false or misleading impression.
Seems pretty cut-and-dry, but for the purposes of this lesson, it is helpful to know that there are different types of lies. The three most commonly referred to are lies of commission, lies of omission, and lies of influence, aka character lies. The reading below neatly summarizes these and provides some examples.
These three types of lies are well-known, and there are many readings that illustrate them. This one from Vanessa Van Edwards is very concise and offers a number of examples. I suggest going through the examples she provides to test your understanding.
The three types of lies are as follows, as described in the reading above:
Now that you have a good idea of what each of these three types of lies entails, take a second to think about which type of lie fits which of Webster's definitions above.
Try and think back to the very brief "Economics 101" lesson that was part of the explanation for externalities. If you recall, I noted that most economic decisions are based on weighing the private benefit against private cost in an effort to maximize private benefit (remember the thrift store table?). This effectively summarizes the neoclassical economic model we've been using in the Western World for the past 150+ years, and it has changed very little in that time. When economics models people's decisions in this manner, the generic person in the model is often referred to as "Economic Man" or "homo economicus," the latter of which is an obvious play on the term homo sapiens. Economic Man was described by Craig Lambert in Harvard Magazine [252] thusly:
Economic Man makes logical, rational, self-interested decisions that weigh costs against benefits and maximize value and profit to himself. Economic Man is an intelligent, analytic, selfish creature who has perfect self-regulation in pursuit of his future goals and is unswayed by bodily states and feelings.
As Lambert says, this is the "standard model...that classical and neoclassical economics have used as a foundation for decades, if not centuries." Most economic models are based on this assumed behavior, but there is at least one major problem with this. Lambert sums up the problem concisely: "But Economic Man has one fatal flaw: he does not exist."
So what does he mean by this?
There are many more examples, as you will read below. But the question is, how do we include this type of irrational behavior into economic models? In a more general sense, it begs the question: "How can we explain such behaviors?" Enter Behavioral Economics. Some of the principles of Behavioral Economics are described below by Alain Samson in The Behavioral Economics Guide 2015 [253]. (I added the emphasis in bold.)
In last year's BE Guide, I described Behavioral Economics (BE) as the study of cognitive, social, and emotional influences on people's observable economic behavior. BE research uses psychological experimentation to develop theories about human decision making and has identified a range of biases. The field is trying to change the way economists think about people’s perceptions of value and expressed preferences. According to BE, people are not always self-interested, cost-benefit-calculating individuals with stable preferences, and many of our choices are not the result of careful deliberation. Instead, our thinking tends to be subject to insufficient knowledge, feedback, and processing capability, which often involves uncertainty and is affected by the context in which we make decisions. We are unconsciously influenced by readily available information in memory, automatically generated feelings, and salient information in the environment, and we also live in the moment, in that we tend to resist change, be poor predictors of future preferences, be subject to distorted memory, and be affected by physiological and emotional states. Finally, we are social animals with social preferences, such as those expressed in trust, altruism, reciprocity, and fairness, and we have a desire for self-consistency and a regard for social norms
It's worth noting that the 2017 Nobel Prize in Economics was awarded to Richard Thaler, who is considered one of the fathers of Behavioral Economics. Here is an article from The Atlantic ("Richard Thaler Wins the Nobel in Economics for Killing Homo Economicus") [254]that explains some of his theories, if you are so inclined. These theories are starting to hit the mainstream!
Read the Introduction to the Behavioral Economics Guide 2015 by Dan Ariely. This can be found in the link below, and in Canvas in the Lesson 5 Module.
The Behavioral Economics Guide provides an excellent introduction to this topic, but the following sums it up pretty well:
- "...if people were simply perfectly rational creatures, life would be wonderful and simple. We would just have to give people the information they need to make good decisions, and they would immediately make the right decisions. People eat too much? Just give them calorie information and all will be well...People text and drive? Just let them know how dangerous it is. Kids drop out of school, doctors don’t wash their hands before checking their patients. Just explain to the kids why they should stay in school and tell the doctors why they should wash their hands. Sadly, life is not that simple and most of the problems we have in modern life are not due to lack of information, which is why our repeated attempts to improve behavior by providing additional information does little (at best) to make things better.
- There are lots of biases, and lots of ways we make mistakes, but two of the blind spots that surprise me most are the continuous belief in the rationality of people and of the markets. This surprises me particularly because even the people who seem to believe that rationality is a good way to describe individuals, societies and markets, feel very differently when you ask them specific questions about the people and institutions they know very well. On one hand, they can state all kinds of high order beliefs about the rationality of people, corporations, and societies, but then they share very different sentiments about their significant other, their mother-in-law (and I am sure that their significant other and mother-in-law also have crazy stories to share about them), and the organizations they work at.
The main thing Ariely is trying to get at here is that people make decisions that are irrational and/or are not good for their own well-being all of the time, and if you ask them they admit it. Yet, modern economic models assume that people always act rationally and in their own self-interest. He provides a lot of examples of this, including texting while driving, overconsumption of alcohol, overindulging in social media, over-eating and more. The point is that there are a lot of damaging behaviors that people engage in despite "knowing better." This is indicative of something being amiss in economic models.
You may be wondering how this all fits into this week's lesson. Okay, here goes: As it turns out, though the field of Behavioral Economics is only recently gaining steam in academics, and to a lesser extent public policy, advertisers have known about irrational behavior for decades. Though they did not call it Behavioral Economics, they have been using its principles to sell stuff to people. And if you ask the right person, they will openly acknowledge this.
Lucky for you, the good folks at Freakonomics Radio [256] have interviewed such a person, and some others familiar with this topic in a recent show. In a more general sense, Behavioral Economics provides insight into how people can be influenced to act irrationally, and even against their own interests. The applications go well beyond advertising! I'm looking at you, in particular, politics. If you have time, I strongly suggest listening to or reading the podcast in the box below. It's done in a really engaging way and is full of good information.
When reading or listening to the show below, pay special attention to the terms social norming, loss aversion, positivity, and perception of scarcity. Note this telling quote from one of the key players in this podcast, and who says it: "The problem with economics is that it’s designed for the perfectly rational, perfectly informed person possessed of infinite calculating ability. It isn’t really designed for the human brain as it is currently evolved."
In the podcast, Dubner interviews Rory Sutherland, vice chairman in the U.K. of Ogilvy and Maher, a global marketing and advertising firm. Sutherland is an avowed proponent of behavioral economics (BE) and makes it clear that the advertising agency has been using BE principles for decades, though they never had a specific name for it. The following are a few important elements from the podcast. (There is a LOT more good information, by the way!):
Hopefully, next time you are looking at advertisements, listening to politicians, or even just listening to others speak, you will pick up on techniques like social norming, loss aversion, positivity, and perception of scarcity.
By now you should be able to:
You have reached the end of Lesson 5! Double-check the to-do list on the Lesson 5 Overview page [260] to make sure you have completed all of the activities listed there before you begin Lesson 6.
In this lesson, we'll go over solar and anaerobic digestion in a little more detail. We will see some of this in our travels, and I want you to have a better understanding of some of the basics.
By the end of this lesson, you should be able to:
To Read | Lesson 6 Online Content | You're here! |
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To Do |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
As was detailed in an earlier lesson, solar energy is electromagnetic (aka radiant) energy that is generated by the (nuclear) fusion of hydrogen atoms into helium atoms in the sun. The amount of radiant energy that is released by an object is related to its temperature, and since the sun is so hot (~10,000º F!) [261], it is able to reach the ~94,000,000 miles (the distance depends on the time of year) to the earth. It is a massive amount of energy! A commonly cited statistic is that enough solar energy reaches the earth each hour to provide all of humanity's energy for an entire year. There is no shortage of solar energy.
Without the sun, life on earth would not be possible. It provides energy for vegetation to grow and provides sufficient heat to allow water to exist in liquid form, among other things. But there are many ways that humans can use this radiant energy more deliberately. The following is an overview of the major types of solar technologies. We could spend weeks analyzing each of these - keep in mind that this is just an overview.
The rest of the solar lesson will focus on solar photovoltaics or solar PV. As noted above, photovoltaic technology (aka the photovoltaic effect) converts radiant solar energy into electricity. View the short video below from the U.S. Department of Energy for a brief explanation. Note that the narrator of the video indicates that photons provide the energy that is converted into electricity. NASA describes [264] the relationship between photons and electromagnetic energy thusly: "Electromagnetic radiation can be described in terms of a stream of mass-less particles, called photons [265], each traveling in a wave-like pattern at the speed of light [266]." So photons are generally considered to be what carries the energy that is emitted in waves.
Okay, so a solar panel converts radiant to electrical energy by using the unique properties of a semiconductor, usually, silicon combined (doped) with other elements (usually boron and phosphorous). But how much energy and power does a panel generate? As you might guess, it depends on a lot of factors. The following is an overview of some of these factors.
We will experience some solar PV installations and technology while traveling, so I provide some more details about it below.
A few more terms that are important to know:
Recall that the rule of thumb is that the optimal tilt is "latitude tilt," and the ideal orientation in the Northern Hemisphere is due south (180º). This begs the question: what happens if the tilt and orientation are not optimal? The answer, as you might guess, is "it depends." This impact can be quantified by something that is called tilt and orientation factor (TOF). The tilt and orientation factor is a decimal that indicates what percent of the maximum solar output you would receive throughout the year at said tilt and orientation. So if you install an array and it has a TOF of 0.85, that means that it will only be able to output about 85% of the energy it would output if it were at the ideal tilt and orientation.
Wilmington, Delaware is at about 40º north. As it turns out, the ideal tilt is closer to 35º (rules of thumb are only rules of thumb, after all!). The tables below show the TOF at different tilts and azimuths. The first table illustrates the TOFs of different tilts, all with an orientation of 180º. The second table shows the TOFs at different azimuths, all at a tilt of 35º (the ideal tilt). (You can investigate the TOF for locations throughout the U.S. by going to the Solmetric website [272].)
Tilt (º) | Azimuth (º) | TOF |
---|---|---|
0 | 180 | 0.87 |
5 | 180 | 0.905 |
10 | 180 | 0.935 |
15 | 180 | 0.959 |
20 | 180 | 0.978 |
25 | 180 | 0.991 |
30 | 180 | 0.999 |
35 | 180 | 1.0 |
40 | 180 | 0.996 |
45 | 180 | 0.985 |
50 | 180 | 0.969 |
55 | 180 | 0.947 |
60 | 180 | 0.92 |
65 | 180 | 0.888 |
70 | 180 | 0.851 |
75 | 180 | 0.81 |
80 | 180 | 0.764 |
85 | 180 | 0.715 |
90 | 180 | 0.662 |
Tilt (º) | Azimuth (º) | TOF |
---|---|---|
35 | 90 | 0.797 |
35 | 100 | 0.833 |
35 | 110 | 0.897 |
35 | 120 | 0.898 |
35 | 130 | 0.926 |
35 | 140 | 0.951 |
35 | 150 | 0.972 |
35 | 160 | 0.986 |
35 | 170 | 0.996 |
35 | 180 | 1.0 |
35 | 190 | 0.997 |
35 | 200 | 0.989 |
35 | 210 | 0.976 |
35 | 220 | 0.956 |
35 | 230 | 0.932 |
35 | 240 | 0.905 |
35 | 250 | 0.874 |
35 | 260 | 0.839 |
35 | 270 | 0.803 |
Okay, now we're ready to calculate the solar output. There are a number of software programs and a formula or two that can do this, but the National Renewable Energy Laboratory (NREL) provides a free one that is well-regarded in the energy industry called PVWatts [273]. In the video below, I demonstrate how to calculate the annual output of the array in the images above, which has the following specs:
Hopefully, by now you have a relatively good grasp on some of the considerations that go into designing and calculating the output of solar PV. Solar PV really took off in the early- to mid-2000s, led by residential array installations, which generally had capacities of a few kW. The solar industry in the U.S. is not dominated by utility-scale solar, which is much cheaper per W to construct because of economies of scale. Utility-scale arrays can be thousands of watts (multiple MWs) in capacity!
Finally, there are a few ways that people can use and pay for solar PV:
You may recall from EM SC 240N that bioenergy is energy that comes from living or recently living things. Common examples include wood from trees used for heating and ethanol from corn used as a gasoline additive. Another form - and one that we will see while traveling - is called anaerobic digestion. "Anaerobic" refers to "without air" and the "digestion" part refers to the microorganisms that digest organic material. Putting it together, anaerobic digestion refers to microorganisms breaking down organic material when no oxygen is present. The following descriptions of anaerobic digestion are from the EPA's Anaerobic Digestion website. All points of emphasis (bold letters) are mine:
Anaerobic digestion is the natural process in which microorganisms break down organic materials. In this instance, “organic” means coming from or made of plants or animals. Anaerobic digestion happens in closed spaces where there is no air (or oxygen). The initials “AD” may refer to the process of anaerobic digestion or the built system where anaerobic digestion takes place, also known as a digester.
The following materials are generally considered “organic.” These materials can be processed in a digester:
- Animal manures;
- Food scraps;
- Fats, oils, and greases;
- Industrial organic residuals; and
- Sewage sludge (biosolids).
All anaerobic digestion systems adhere to the same basic principles whether the feedstock is food waste, animal manures or wastewater sludge. The systems may have some differences in design but the process is basically the same
Biogas is generated during anaerobic digestion when microorganisms break down (eat) organic materials in the absence of air (or oxygen). Biogas is mostly methane (CH4) and carbon dioxide (CO2), with very small amounts of water vapor and other gases. The carbon dioxide and other gases can be removed, leaving only the methane. Methane is the primary component of natural gas.
The material that is left after anaerobic digestion happens is called “digestate.” Digestate is a wet mixture that is usually separated into a solid and a liquid. Digestate is rich in nutrients and can be used as fertilizer for crops
Biogas is produced throughout the anaerobic digestion process. Biogas is a renewable energy source that can be used in a variety of ways. Communities and businesses across the country use biogas to:
- Power engines, produce mechanical power, heat and/or electricity (including combined heat and power systems);
- Fuel boilers and furnaces, heating digesters and other spaces;
- Run alternative-fuel vehicles; and
- Supply homes and business through the natural gas pipeline
How biogas is used and how efficiently it’s used depends on its quality. Biogas is often cleaned to remove carbon dioxide, water vapor and other trace contaminants. Removing these compounds from biogas increases the energy value of the biogas...Biogas treated to meet pipeline quality standards can be distributed through the natural gas pipeline and used in homes and businesses. Biogas can also be cleaned and upgraded to produce compressed natural gas (CNG) or liquefied natural gas (LNG). CNG and LNG can be used to fuel cars and trucks.
Digestate is the material that is left over following the anaerobic digestion process. Digestate can be made into products like:
- Bedding for livestock;
- Flower pots;
- Soil amendments; and
- Fertilizers.
When properly processed, dewatered digestate can be used as livestock bedding or to produce products like flower pots.
Digestate can be directly land applied and incorporated into soils to improve soil characteristics and facilitate plant growth. Digestate can also be further processed into products that are bagged and sold in stores. Some emerging technologies can be employed post-digestion to recover the nitrogen and phosphorus in digestate and create concentrated nutrient products, such as struvite (magnesium-ammonium-phosphate) and ammonium sulfate fertilizers.
The video below from Michigan State University does a great job of explaining how they use anaerobic digestion to convert organic cafeteria and farm waste into useful energy and fertilizer. To view the transcript (and the video on YouTube, click this link [276].)
Thermodynamically speaking, the energy conversion process is:
It is extremely important to keep in mind that this is a natural process, and thus will occur any time organic material is subjected to low- or no-oxygen conditions. One important implication of this is that organic material that ends up buried in a landfill will convert partially to methane because there is very little oxygen underneath all of that "junk." As I'm sure you recall, methane is about 30 times more potent than CO2 in terms of its global warming impact. If you took the same organic material and let it biodegrade in the open air (i.e., with access to oxygen) it would release mostly CO2. The sad irony of this is that well-meaning people and companies can actually make the (climate change) problem worse if their biodegradable containers end up in the landfill. This methane can be captured, and in many places in the U.S. and throughout the world is. This is also why impoundment hydroelectric facilities (big dams) can cause methane emissions - organic material collects upstream of the dam, and low-oxygen conditions often occur near the bottom of the reservoirs, causing methane to be released. Systems thinking, everyone!
Digesters can be pretty much any size. I've seen one as small as a car inner tube that was used to power a gas grill and heat a small greenhouse. Some of them can be larger, as you'll see below.
The pictures below are from a cooperatively-owned anaerobic digester in Lemvig, Denmark. I'm particularly fond of this because the entire setup is owned equally by about 25 farmers, and is a non-profit operation. All of the organic waste from the farms is transported to the digester, including leftover vegetation and various types of manure. The biogas is used to generate electricity in a turbine which is either sold to the grid or used in the digester, and the "waste" heat is used to run the anaerobic digester. The remaining heat is used for district heating for the town - it heats up water, which is then run through underground pipes to be used to heat homes. This type of generator is considered cogeneration, which means it is used to generate electricity and useful heat. Recall that most power plants are about 35% efficient because so much energy is wasted as heat. Believe it or not, this cogeneration system is over 90% efficient when you include all of the "waste" heat that is captured and used! All digestate is then returned to the local farms and used as organic fertilizers. It is truly a closed-loop system!
The images below show details of a smaller installation in Kussnacht, Switzerland. This installation is run by a single farmer (Seppi), who collects organic waste from his farm, other local farms, and area restaurants. Like the one above, Seppi collects the biogas and uses it in a cogeneration system that is about 90% efficient (50% heat, 40% electricity, and 10% is wasted). He runs a 100 kW generator and uses the electricity on his farm and sells the leftover to the grid. The heat is used to run the digester, and to provide space and water heating to his farm. He uses some digestate on his farm and gives the rest back to local farmers for free.
It just so happened that at the time of our visit (I brought students there for a study abroad experience), his previous digester had burnt down due to a generator fire. The upshot of this is that we were able to see inside the digester he was building, which you will see below.
By now you should be able to:
You have reached the end of Lesson 6! Double-check the to-do list on the Lesson 6 Overview page [277] to make sure you have completed all of the activities listed there before you begin Lesson 7.
In this lesson, we'll go over some of the basics of wind and microhydroelectric energy, including how to do some basic output calculations.
By the end of this lesson, you should be able to:
To Read | Lesson 7 Online Content | You're here! |
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To Do |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
As you may recall, the wind is caused by differential solar heating across the surface of the earth (as well as the shape of the earth), which causes large- and small-scale high and low-pressure systems to form. Air moves from areas of higher pressure to areas of lower pressure, which is what causes wind to occur. (If you are interested, this National Geographic site [278] explains some of the finer points of this process, including a lot of pictures.)
Wind, then, is just air that is moving. Simply put, this air has kinetic energy because wind has mass and is moving. (Anything in motion with mass has kinetic energy.) Because of the First Law of Thermodynamics, the energy in the wind must come from somewhere else. This "somewhere else," is solar energy. This energy (and power) can be quantified. See later in this lesson for an explanation of how to calculate this.
Average wind speeds vary widely by geographical location. Take a few minutes to inspect the wind speed charts from the National Renewable Energy Laboratory below. Note the location of the greatest and smallest wind speeds, and think about the physical characteristics of those areas (e.g., flat, mountainous, on-shore, off-shore, etc.). Click here for a larger version of the 30 m wind speed image [279] and click here for the 80 m image. [280] Note that the average wind speed is higher at 80 m at the same location. Wind speed generally increases with height due to the decreasing influence of friction from the earth's surface and things on it. Modern turbines are generally tall enough to take advantage of 80 m wind speeds.
In addition to variability being a barrier to wind deployment, the location of wind resources is as well. In general - and certainly, in the U.S. - the best onshore wind resources are not located near major population centers. Approximately 50% [281] of the U.S. population lives within 50 miles of the coast, but as you can see in the maps below, this is generally not where the greatest onshore wind is located. This is a problem because transporting electricity over power lines results in energy loss (as heat) due to electrical resistance in wires. The longer the electricity has to travel, the more energy is lost. To minimize this loss, large (and very expensive) power lines must be built. As you can imagine, this type of infrastructure is lacking in areas of the country that do not have large populations.
However, it is clear from the second map that significant offshore wind resources are available very near the coast. Unfortunately, offshore wind is still expensive (remember from a previous lesson [282] that the LCOE is the highest of those listed). That, combined with resistance from local inhabitants had kept the offshore wind at bay until 2016 when the first offshore wind farm (albeit a very small one) in the U.S. was opened in Rhode Island [283]. There are over two dozen in the planning stages [284] as we speak. This is likely an area of growth in the near future.
Now for some terminology and other considerations:
See below for a diagram of key components of wind turbines:
There is a lot to digest here. The components I'd like you to know are as follows. All quoted text is from the U.S. Department of Energy [287]:
The basic energy conversion process is as follows:
Turbines come in a very wide variety of sizes and capacities. The images below show some of this. (We will see the second turbine in Golden, CO!)
The power in the wind is given by the following equation:
Power (W) = 1/2 x ρ x A x v3
Thus, the power available to a wind turbine is based on the density of the air (usually about 1.2 kg/m3), the swept area of the turbine blades (picture a big circle being made by the spinning blades), and the velocity of the wind. Of these, clearly, the most variable input is wind speed. However, wind speed is also the most impactful variable because it is cubed, whereas the other inputs are not.
The following are calculations for power available in the wind at three different velocities for the Northwind 100C turbine. This is the newer version of the Northwind 100A on the previous page. The calculations will show what happens when you double, then triple the velocity. Take a moment to think about how much available power will increase if you double and triple the velocity:
As you can see, when the velocity doubles, the power increased by a factor of 8 and when the velocity triples, it increases by a factor of 27. This is because the velocity is cubed: 23 = 8 and 33 = 27.
The output of a wind turbine is dependent upon the velocity of the wind that is hitting it. But as you will see, the power is not proportional to the wind velocity. Every turbine is different. In order to determine the output of a specific turbine at a given wind velocity, you need its power curve. The power curve and corresponding data for the Northwind 100C can be seen below:
wind speed (m/s) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
---|---|---|---|---|---|---|---|---|---|---|---|---|
power output (kW) | -0.5 | -0.5 | 1.2 | 7.2 | 14.5 | 24.7 | 37.9 | 58.7 | 74.8 | 85.1 | 90.2 | 94.7 |
wind speed (m/s) | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
power output (kW) | 95.3 | 95.1 | 94.2 | 92.9 | 91.2 | 88.9 | 87.1 | 84.1 | 81.3 | 78.6 | 75.1 | 74.3 | 71.7 |
As you can see, even though this is a 95 kW turbine, it only provides (approximately) that much power at a very limited number of wind speeds - about 12 m/s through about 15 m/s. Counterintuitively, the power output decreases if the wind speeds up past that point. For safety reasons, the turbine will stop spinning if the wind speed is higher than 25 m/s.
Assuming the turbine is operating properly, the output calculation is pretty straightforward. You just multiply the output at a given velocity by the number of hours the wind is blowing at that velocity. For example, let's assume that the wind hitting a Northwind 100C in a given day has the following velocities. (Note that in reality, the wind would likely change much more frequently than this. I just wanted to make the math relatively easy.):
velocity (m/s) | number of hours at that velocity |
---|---|
6 | 4 |
8 | 8 |
12 | 5 |
15 | 4 |
16 | 3 |
16 | 3 |
The total output at 6 m/s would be: 24.7 kW (the output at 6 m/s from the power curve table) x 4 hrs = 98.8 kWh.
Based on the power curve table above, the total output for this day would be:
velocity (m/s) | number of hours at that velocity | total output (kWh) |
---|---|---|
6 | 4 | 98.8 |
8 | 8 | 469.6 |
12 | 5 | 473.5 |
15 | 4 | 376.8 |
16 | 3 | 278.7 |
16 | 3 | 278.7 |
Total | 24 | 1,697.4 |
One last consideration to make for wind turbines (or any energy source) is something called capacity factor. Capacity factor indicates how much energy is generated by a source relative to the maximum amount of energy it could provide. This is expressed as a percentage, and is usually determined over the course of a single year. This provides insight into how well-sited the turbine is, but in general indicates how available an energy source is throughout the year. The closer to 100%, the more the energy source is available throughout the year.
The formula is capacity factor = actual output/maximum possible output.
For a wind turbine, the maximum possible output would be the capacity x 8760 hr (there are 8760 hrs in a year). So for the Northwind 100C, the maximum output is: 95 kW x 8760 hr/yr = 832,200 kWh/yr (or 832.2 MWh). If the actual output over the course of a year was 250,000 kWh, the capacity factor would be:
The average capacity factor of the U.S. wind fleet hovers around 32% - 34% [296], but new turbine designs have been tested in the 60%+ range, like this forthcoming 12 MW behemoth [297] by GE. It's not unusual to see 40% and up capacity factors for well-sited wind farms.
Like moving air, moving water has kinetic energy (it has mass and it is moving). But water is much denser than air - this is obvious to anyone who has waded across a deep stream or played in ocean waves. If you recall, air has an average density of 1.225 kg/m3. One cubic meter of water, on the other hand, has a mass of 1,000 kg, or one metric ton (aka one tonne). It may be hard to believe, but a cube of water that is about 3.3 feet on each side weighs over 2,000 pounds!
Where does this kinetic energy come from? Take a second to think about it...Water only flows downhill, so if you see moving water it came from a higher elevation. This kinetic energy is thus converted from gravitational potential energy. How did it get this gravitational potential energy? Well, something had to take the water up to the higher elevation. The only natural way this happens is through evaporation, which is almost always caused by the sun, in a number of different ways: Water that is heated by the sun may evaporate. Wind also evaporates water, but remember that wind gets its energy from the sun. Plants evapotranspirate water, but again, they get their energy from the sun. Even the minor amount exhaled by humans is solar energy since all of our energy comes from the sun. The only major exception is that some evaporative heat is provided by geothermal energy from the earth, e.g., in volcanoes. At any rate, almost all hydropower/energy comes from the sun
Humans have been using hydropower for thousands of years [298]. According to the U.S. Department of Energy, the Greeks used water to spin wheels to grind grain over 2,000 years ago. Modern humans figured out how to convert hydropower to electricity by using a turbine and generator (see below), which is called hydroelectricity, for obvious reasons. The first known use of hydroelectricity [299] was in 1878 to power a single lamp in Northumberland, England. Larger plants were installed in 1881 in the U.S., and the first commercial-scale plant was built in the U.S. in 1893 in Redlands, California.
All hydroelectric power plants operate on the same principle. Moving water spins a turbine, which spins an electric generator. See below for an illustration of an impoundment facility, which uses a dam to create a reservoir of water.
Explaining all components in this image goes beyond the scope of this lesson, but feel free to click on the image above or here for a clickable image [301] to learn more about each. The important terms for this lesson are:
This basic process - flowing water spins a turbine, which spins a generator - is common to all types of hydroelectricity installations. There can be any number of other components, and the size/scale may be different, but this core process is the same.
Like all other electricity sources, hydroelectric power plants have a rated capacity. Large impoundment facilities can have capacities on the order of GWs (billions of watts). The largest facility in the world - the Three Gorges Dam in China - has a capacity of 18 GW. According to the U.S. Department of Energy, a microhydro system has a capacity of up to 100 kW [302]. Most systems are much smaller. A residential-scale microhydro system is more likely to be a few kWs in size.
A typical microhydro system is illustrated in the image above. Systems can vary significantly in style and size, but according to the U.S. DOE, the following components are commonly seen in most systems [304]:
As described above, the kinetic energy in flowing water starts out as gravitational potential energy. The gravitational potential energy of a given amount of water at any elevation can be calculated using the following equation:
The force of gravity is essentially a constant (it gets a little bit smaller with height). Thus, all else being equal, as height and mass increase, the potential energy increases. Keep in mind that this equation only illustrates the maximum kinetic energy available to a hydropower system. In reality, there are always losses by the time the kinetic energy is converted to electricity.
The power available in water at height is given by a similar equation:
Again, this is only the hypothetical maximum - it is impossible to capture all of this power in a turbine. This equation is almost the same as the potential energy equation - you just substitute discharge for mass. Since the discharge is kg/s, or mass divided by time, if you compare the two equations, the power equation is the energy equation divided by seconds. This makes sense if you think about it: the potential energy is given in Joules, and the power equation is given in watts. Recall that 1 J/s = 1 W. Makes sense, right?
It turns out that calculating the approximate power output of a microhydro system is not terribly difficult. According to the U.S. DOE, a typical system has an efficiency of about 53%. This includes losses from the nozzle, the wiring, the generator, and a few other things. The power of a microhydro system with this efficiency is approximately:
To determine the gross head, you measure how many feet above the generator the penstock starts. Note that this is not the same as the length of the penstock. The penstock is sloped, and thus will be longer than the head. The head loss is based on a few factors, including the diameter of the penstock, the pressure inside the penstock, and the number of turns and fittings there are in the penstock. According to Homepower Magazine, 30% is a typical amount of head loss, which means you would calculate the gross head time 0.7 to determine the net head. The flow of a stream through a penstock can vary wildly, from a few gallons per minute to a few hundred (or more). To provide some context a garden hose usually has a flow of about 20 gallons per minute, though this can also vary significantly depending on a number of factors.
Let's say I have a property in which I can create a diversion channel and forebay 100 ft above a power house, and I measure my flow at 50 gpm. Assuming a good system design which includes a head loss of 30%, my output would be:
This lesson only scratches the surface of microhydro systems. There are many designs and factors to consider. Each site is different. For a more detailed explanation, see this website from the U.S. DOE [305], and for a good case study, see this example from Homepower Magazine ( [306]starting on p. 32). There are dozens of videos on YouTube that detail specific systems, many of which are worth checking out if you are interested.
If you are interested in learning more about the power and energy available in water for hydroelectric, see this video presentation I put together [307]for another course.
Starting this week and moving forward — each week, I will provide links to some of the locations/organizations we will visit. This is not required reading. I suggest browsing through them if/when you have time. This may help inspire your final project proposals!
By now, you should be able to do the following:
You have reached the end of Lesson 7! Double-check the to-do list on the Lesson 7 Overview page [312] to make sure you have completed all of the activities listed there before you begin Lesson 8.
The focus of this lesson is on ways to sustainably manage natural resources.
By the end of this lesson, you should be able to:
To Read | Lesson 8 Online Content | You're here! |
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To Do |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
I'm sure you've heard the term "natural resources" used many times, e.g., when someone talks about "preserving natural resources" or when you hear about "natural resource management." It's a pretty innocuous term, and seemingly straightforward. If you asked someone what natural resources are, they would probably say something about "resources provided by nature, such as trees, minerals, and food" or something to that effect. (This is actually a pretty good definition, by the way!) When thinking about the definition, it's easy to focus on the "nature" component and look past the "resources" part. Specifically, it is important to note that "natural resources" is an anthropocentric (human-centered or focused) term. It is a concept that only exists because of humans because it refers to things that impact humans. To demonstrate this, let's look at a few definitions of natural resources:
things such as minerals, forests, coal, etc. that exist in a place and can be used by people
~Cambridge Dictionary [313]
industrial materials and capacities (such as mineral deposits and waterpoer) supplied by nature
~Merriam-Webster [314]
a naturally occurring source of wealth, as land or water; the natural wealth of a country, consisting of land, forests, mineral deposits, water, etc.
~dictionary.com [315]
Any way you slice it, without humans natural resources don't exist, they would just "be" or just be "nature." This is important to keep in mind as we go over this lesson: by definition, natural resources only exist as a concept because they can be used by humans.
Personal consumption expenditures (household spending on goods and services) constitutes nearly 70% of U.S. GDP [316]. Much of this is on services, but Americans now spend nearly 4.5 trillion dollars on "goods," which includes everything from food, to energy, to cars, houses, clothing, and other goods. See the charts below from the Federal Reserve Bank of St. Louis [317] for these consumption trends over the past 60+ years. They are an excellent, reliable resource for economic data. (For a good explanation of goods and services, see this explanation [318]from thebalance.com.)
The moral of the story: Americans buy a lot of stuff! This has many implications, but one is particularly important with respect to this lesson. Namely, almost all of this spending requires the use of natural resources. Obviously, things like cars and clothes require raw natural resources to produce, though you may be surprised at how many. Take a look at the infographic below from Allianz to get some idea of how many different natural resources from all over the world are needed to make a car.
All goods require some mixture of raw natural resource extraction, manufacturing, processing, shipping, packaging, use, and disposal. All of this requires energy and resources. Most of this use, as indicated in the infographic above, is hidden. I will give you one more quick example: I used to assist with industrial energy audits on a part-time basis while in college. One of the places we audited was a "feed mill," which is essentially a factory that produces chicken feed. (Related note: Delaware is considered the poultry capital of the U.S.) The facility looked a lot like the one in the image below.
I was dumbfounded at how much energy and resources went into just producing feed for chickens! While I was there, there was a constant arrival of tractor trailers hauling raw ingredients - corn, soybean, nutrient mixes, and other things - and the machinery was massive and energy-intensive. According to Delmarva Poulty Industry, Inc. [324] (Delmarva includes parts of Delaware and the eastern shores of Virginia and Maryland), the Delmarva chicken industry had the following specifics in 2017:
The point here is not to go in-depth into the poultry or automobile industries, but to indicate that nearly everything you purchase is the product of a tremendous use of resources, much of which is hidden. But services such as healthcare and education also require the use of resources. Medical facilities need chairs, tables, x-ray machines, paper, and so forth, and use a lot of energy. Even an online class requires physical resources, in particular, electricity and all of the lifecycle resources used to generate that energy (mines, power plants, power lines, equipment to manage it all, etc.), but also the device you are viewing this on is the result of a global supply chain of goods. This type of lifecycle resource use and our consumption-driven economy are major contributors to the fact that we would need nearly 5 planet earths to satisfy humanity's needs if everyone lived like the average American.
The problems associated with the massive amount of resources used to produce everyday goods and services is compounded by the fact that this system is based mostly on linear resource use. This is often referred to as "take, make, waste." An illustration of the basic resource flow is shown below.
This linear model typically goes something like the following:
This model requires the constant input of raw natural resources because of the waste and emissions along the way, and because most of the "waste" is dumped in a landfill (and possibly incinerated), and all of this is done primarily with the use of non-renewable energy. This is a major reason why our ecological footprint is so large and we are using natural resources at such a high rate. Globally, only about 14% [326] of the primary energy used is renewable. In the U.S., over half of municipal solid waste (MSW) ends up in a landfill. Keep in mind that municipal solid waste is basically household garbage, and does not include construction, industrial, or farming waste, which make up a large portion of the waste stream. All of this adds up to 262.4 million short tons of MSW generated (about 4.5 pounds per person per day), of which about 138 million tons ends up in a landfill, according to the U.S. EPA [327].
Contrast this with a circular resource flow model, in which there is almost no waste. Any resources that are unused in each step are reintegrated back into the system. Manufacturing "waste" is reused or recycled, as are final products used by the end user. If this could all be run using renewable resources, then much of the pollution would be eliminated as well. In fact, in an ideal circular resource system, the idea of "waste" does not exist. This is the philosophy behind "zero waste" initiatives. Note that because of thermodynamics, there will be some inefficiency, and thus some loss. This is why there will still be some natural resource input required.
It is worth noting that nature utilizes circular resource flow. Recall that it was stated above that the concept of natural resources is anthropocentric. There is no waste in nature - everything is a resource for some other process. Resources move around in continuous flows, and all "waste" is reintegrated back into the system, with the exception of some heat loss that is radiated back to space. All of this is of course driven by renewable energy, and any energy lost to space is offset by energy coming in from the sun. This is why many zero waste (and other sustainability) advocates say that the more we can design human systems to mimic natural systems, the more sustainable those systems will be. As you will see in a future lesson, this is the fundamental philosophy of permaculture.
The Zero Waste Alliance provides an excellent visualization of what such a system could look like. The images below show natural resource flows. The thickness of the flows indicates the relative amount of resources flowing through that part of the system. As you can see, by recovering most of the "waste" throughout, the raw materials flow (at the far left of each diagram) is greatly reduced. Note that the second image shows an idealized flow - there will be some loss due to thermodynamics. Even without thermodynamic loss, some natural resource extraction is required because some resources cannot be directly reused in the manufacturing process.
No doubt you have seen some variation of the image below. Most recyclable packaging has a triangle design, which indicates that it is recyclable. You are probably familiar with the phrase "reduce, reuse, recycle," which is hammered home to (most) kids at a very early age in the U.S. The image clearly gives a nod to circular resource use (follow the arrows!). Each term refers to a slightly different way to manage waste. I provide an example of each in parentheses as it relates to a plastic water bottle:
However, what most people do not know is that "reduce, reuse, recycle" is actually a priority list. In other words, the best way to minimize the impact of waste is to not use it in the first place (reduce), the second best way is to reuse it, and the third best way is to recycle it. Recycling requires a lot of inputs: inefficient trucks to pick it up and transport it, massive machinery to sort it and break it down, more machinery to produce the new good (often after shipping the raw resource far away), then more energy and resources to distribute the good. This entire process uses energy and generates waste. Reuse is less impactful because it cuts out all of the downstream impacts of recycling, but it does not eliminate all of the upstream impacts that resulted from producing the good in the first place.
While all of this is true, recycling is still much more beneficial than landfilling! The following are some statistics from the EPA [330]. All information was taken from WARM, the Waste Reduction Model. (Click here to download the Excel file [331] and do your own analysis, or just explore the data.) Note that MMBTU is one million BTUs of energy, and MTCO2e refers to one megaton of carbon dioxide equivalent:
material | reduction energy savings (MMBTU/ton) | recycling energy savings (MMBTU/ton) | combustion energy savings (MMBTU/ton) | reduction emissions savings (MTCO2e/ton) | recycling emissions savings (MTCO2e/ton) | combustion emissions savings (MTCO2e/ton) |
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aluminum cans | 89.69 | 152.76 | -0.60 | 4.91 | 9.11 | -0.04 |
glass | 6.9 | 2.13 | -0.50 | 0.53 | 0.28 | -0.03 |
PET plastic | 50.26 | 31.87 | 10.13 | 2.20 | 1.12 | -1.21 |
corrugated cardboard | 33.23 | 0.69 | 6.64 | 5.60 | 3.12 | 0.51 |
newspaper | 36.46 | 16.49 | 7.53 | 4.77 | 2.75 | 0.58 |
Notice that with the exception of aluminum cans, the energy and emissions reductions are always greater when you reduce than when you recycle. Based on what I could see in the WARM spreadsheet, aluminum cans are the only material for which recycling is more impactful. Also note that some materials require more energy to burn than they do to landfill (see the negative numbers), and for ALL materials listed, combustion is worse for emissions than recycling or reducing.
The circular economy, as you will see below, utilizes circular resource use.
There are a few ideas underlying the circular economy concept, as described in the videos:
The MacArthur Foundation notes that the circular economy is "about a rethinking of the operating system itself." This is a very important point! The take-make-dispose process is systemic, and is deeply ingrained in society. If we are to get past this mindset, systemic change is required.
Of course, we are socialized to believe that ownership is important (Americans in particular love buying stuff), so the establishment of a circular economy will require social change. This may seem a difficult hill to climb. Well, it is, actually, but allow me to provide one example of why it may be more feasible than you think. Consider the ubiquity of Uber and Lyft. It may be difficult to imagine, but try to think back 10 years ago, before ridesharing existed. Treating automobile transportation as a service was mainly reserved for taking cab rides in cities. Now you can take an Uber in over 60 countries [332] across the world, and the service is available even in rural areas of the U.S. The point here is not that Uber and Lyft are examples of the circular economy (though they do minimize the necessity of automobile production), but that personal transportation is increasingly being viewed as a service. It is a rather commonly held belief [333] that autonomous vehicles will reduce vehicle ownership. Rideshare and car companies are already testing driverless vehicles, and in the not-too-distant future, they will increasingly own their own vehicle fleet instead of paying others to drive, or in the case of car companies, expecting consumers to buy their cars. If/when that happens, it will be to their benefit to extend the use of their fleet as long as possible.
Please watch the video below for some insight into an application of the circular economy called Cradle to Cradle Design.
As you can see, cradle to cradle (C2C) concept is an application of the circular economy. The concept is summed up rather well in the video when they state that C2C is all about "keeping all materials in continuous cycles, stimulating the use of renewable energy only, and celebrating diversity," though there is more to it, as you will see below. The following are some of the key points from the video above:
The Cradle to Cradle Products Innovation Institute [334] has taken this concept beyond the conceptual phase and created a process to certify products using their Cradle to Cradle CertifiedTM product standard [335]. The standard is described as follows:
The Cradle to Cradle Certified [336]™ Product Standard [336] guides designers and manufacturers through a continual improvement process that looks at a product through five quality categories — material health, material reutilization, renewable energy and carbon management, water stewardship, and social fairness. A product receives an achievement level in each category — Basic, Bronze, Silver, Gold, or Platinum — with the lowest achievement level representing the product’s overall mark.
Product assessments are performed by a qualified independent organization trained by the Institute [337]. Assessment Summary Reports are reviewed by the Institute, which certifies products meeting the Standard requirements, and licenses the use of the Cradle to Cradle Certified™ word and design marks to the product manufacturer. Every two years, manufacturers must demonstrate good faith efforts to improve their products in order to have their products recertified.
The five quality categories [338] are as follows:
Material Health: Knowing the chemical ingredients of every material in a product, and optimizing towards safer materials.
Material Reutilization: Designing products made with materials that come from and can safely return to nature or industry.
Renewable Energy & Carbon Management: Envisioning a future in which all manufacturing is powered by 100% clean renewable energy.
Water Stewardship: Manage clean water as a precious resource and an essential human right.
Social Fairness: Design operations to honor all people and natural systems affected by the creation, use, disposal or reuse of a product.
If a product would like to go for C2C certification, it is evaluated based on these five categories. It receives a score in each category - basic, bronze, silver, gold, or platinum. These are also the five levels of cradle to cradle certification. The certification level is based on the lowest score that the product receives in these categories. For example, if a product earns a "gold" score in material health, material reutilization, renewable energy & carbon management, and water stewardship, but only earns a "basic" score in social fairness, then the product is certified as "basic." Another important aspect to point out is that all products must be recertified every two years, and in that time, must demonstrate good faith efforts to improve the products.
Here are some more site visits! Again, this is not required reading. I suggest browsing through them if/when you have time. This may help inspire your final project proposals!
By now, you should be able to do all of the following:
You have reached the end of Lesson 8! Double-check the to-do list on the Lesson 8 Overview page [343] to make sure you have completed all of the activities listed there before you begin Lesson 9.
The focus of this lesson is to consider the negative sustainability impacts of food production, and investigate solutions to these problems.
By the end of this lesson, you should be able to:
To Read | Lesson 9 Online Content | You're here! |
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To Do |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
Other than energy, it is through food that most of us most frequently directly interact with sustainability. Humans cannot survive without food, and most (and probably all) of you reading this eat multiple meals each day. The food industry has immense sustainability implications, including soil health and conservation, water use, forest clear-cutting, environmental and social justice, economics and equity, and much more. The following provides some insight into a few of these issues.
You probably recall from a previous lesson that irrigation is the single biggest user of freshwater in the United States. You may also recall the large water footprint of some common foods. The following are footprints of common main dishes, according to the Water Footprint Network [344] (see Water Footprint report [345]). (Note that these are global averages. Also, 1 litre/kg equals about 0.12 gal/lb.):
If you are interested, the Huffington Post does a nice job of comparing the water footprint of common foods [346]. (They use Water Footprint Network data.)
Almost all of the water used in producing meat is the result of irrigating the crops that are used to feed the animals, and some irrigation methods are more efficient than others. (Oregon State University Cooperative Extension provides a good analysis of various irrigation techniques [347] if you are interested in learning more.)
One sustainability impact that happens on more of a macro scale is something called a "dead zone." The National Oceanic and Atmospheric Administration (NOAA) explains dead zones [348] thus:
Less oxygen dissolved in the water is often referred to as a “dead zone” because most marine life either dies, or, if they are mobile such as fish, leave the area. Habitats that would normally be teeming with life become, essentially, biological deserts.
Hypoxic zones can occur naturally, but scientists are concerned about the areas created or enhanced by human activity. There are many physical, chemical, and biological factors that combine to create dead zones, but nutrient pollution is the primary cause of those zones created by humans. Excess nutrients that run off land or are piped as wastewater into rivers and coasts can stimulate an overgrowth of algae, which then sinks and decomposes in the water. The decomposition process consumes oxygen and depletes the supply available to healthy marine life.
Dead zones occur in many areas of the country, particularly along the East Coast, the Gulf of Mexico, and the Great Lakes, but there is no part of the country or the world that is immune. The second largest dead zone in the world is located in the U.S., in the northern Gulf of Mexico.
Dead zones happen all over the world and are in fact a natural occurrence. However, humans have significantly increased the incidence of dead zones, including the one in the Gulf of Mexico, which grows to about the size of New Jersey every summer, as you will see in the video below. These dead zones are caused by eutrophication, which is when a body of water has an excessive amount of nutrients (primarily nitrogen and phosphorous) that lead to unusually high plant/algae growth. (Note that eutrophication just refers to excess nutrients, but this often results in a dead zone.) When eutrophic streams and rivers empty into ponds, lakes, or other open bodies of water (such as the Gulf of Mexico), it causes excessive algae growth and ultimately leads to anoxic ("oxygen-less") conditions near the bottom of these bodies of water. NOAA does a good job of explaining eutrophication in the video below.
Eutrophication has a few anthropogenic causes, but the primary one is the use of artificial fertilizers on farms. Fertilizers feed plants, but if they get into bodies of water they feed algae. The video below from NOAA provides a good explanation of this. Please note that the explanation at the end of the video of what causes the dead zone is incomplete: waste from organisms that eat the phytoplankton plays a role in the dead zone, but (as described in the video above) the main cause of dead zones is when bacteria eat the dead phytoplankton after they sink to the bottom.
Over the past 10 - 15 years, food deserts have (slowly) become a more prominent issue. The following is a summary from the U.S. Centers for Disease Control [349] (emphasis added):
Food Desert
Food deserts are areas that lack access to affordable fruits, vegetables, whole grains, low-fat milk, and other foods that make up a full and healthy diet (1). Many Americans living in rural, minority, or low-income areas are subjected to food deserts and may be unable to access affordable, healthy foods, leaving their diets lacking essential nutrients.What's the Problem?
Rural, minority, and low income areas are often the sites of food deserts because they lack large, retail food markets and have a higher number of convenience stores, where healthy foods are less available (2). Studies have shown that food deserts can negatively affect health outcomes but more research must be done to show how that influence occurs. There appears to be a link between access to affordable nutritious foods and the eating of these foods, meaning less access may lead to less incorporation of healthy foods into the populations’ diets.Who's at Risk?
Because there is no standard definition of a food desert, estimates of how much of the population is affected vary by quite a bit. However, it’s safe to say that many Americans have limited access to affordable nutritious foods because they do not live near a supermarket or large grocery store. Transportation is specifically part of the USDA food desert definition. Only common theme among food desert definitions is that there is limited access.Can It Be Prevented?
Food deserts can be improved through several different types of efforts. Establishing a community garden where participants share in the maintenance and products of the garden and organizing local farmers markets are two efforts that community members themselves can do (3, 4). Local governments can improve local transportation like buses and metros to allow for easier access to established markets (5). They can also change zoning codes and offer economic or tax incentives to attract retailers with healthier food offerings to the area (6).The Bottom Line
Food deserts are a big problem for many Americans that may limit their ability to eat healthy and nutritious foods on a regular basis. However, there are a variety of ways that local governments and community members can both improve food access in their neighborhoods.Case Example
Maria is a 60-year-old woman living in a low-income area of St. Louis. As she’s gotten older, she hasn’t been able to get around as well and doesn’t have a car. She usually eats a lot of unhealthy and microwavable foods because the closest store to her apartment is the local convenience store around the corner. She wishes that she could eat better and begins talking to some of her neighbors and other families in the building to get their input. Maria and her next-door neighbor Sylvia organize all the residents in their building to establish a community garden on the roof of the building so that they will all have fresh fruits and vegetables to share.
As indicated above, there is no one definition of a food desert, but it is meant to indicate a lack of access to fresh foods. The U.S. Department of Agriculture (USDA) considers three ways to define a food desert [350]. (The number of people in the U.S. in each category as of 2017 are in parentheses.):
The USDA has created a Food Access Research Atlas (available here) [351], where you can explore food deserts across the U.S. Feel free to tool around with it. (You will have to explore it for this week's quiz.)
A topic closely related to food deserts is food insecurity. The USDA defines food insecurity [352] and very low food security as follows:
The USDA provides an annual report and analysis on food insecurity in the U.S. through its Economic Research Service. Highlights (okay, lowlights) from the "Household Food Security in the United States 2017 [353]" report summary (full Household Food Security [354]report available here [354]) include:
Permaculture is another one of those concepts that have no single definition, but I like the succinct definition offered by Geoff Lawton [355], one of the more well-known permaculture teachers and practitioners in the world when he stated that permaculture is "a system of design that provides all of the needs for humanity in a way that benefits the environment." Another way to describe it is "designing human systems to mimic natural systems" and "designing systems that work with nature instead of against it." No matter how you define it, it refers to a design system - it integrates concepts from a wide array of disciplines/topics (hydrology, soil science, biology, ecology, renewable energy, forestry, and more) - and utilizes them when designing systems, such as gardens, farms, houses, neighborhoods, and more. It is most commonly used to design food systems, though. Everything from a backyard garden to a large farm can be designed using these principles.
The concept and term "permaculture" was coined by Bill Mollison and David Holmgren in Australia in the 1970s. It was originally a concatenation of the terms "permanent agriculture" because it initially focused on food production systems, but came to be known as a shortened form of "permanent culture" because it can be used to address all aspects of human culture/settlements.
The Permaculture Research Institute provides an excellent one-page description of permaculture. Please read through it before continuing.
The following are some highlights from the reading:
I want you to consider one additional concept that is mentioned in this summary. They mention that permaculture helps establish resilience. Resilience can be thought of as the ability to return to an original state after encountering a shock to the system. This has become a major focus of sustainability efforts. People recognize that "bad" things such as climate change, oil price spikes, and economic collapse will happen, but we do not know when. Much effort in sustainability design, thought, and policy is focused on establishing resilient communities (and cities, states, and countries) that will be able to withstand such shocks in such a way that suffering and distress will be minimized.
From a climate change perspective, this is primarily a focus on adaptation, i.e., adapting our communities to thrive in an uncertain climate future. This usually involves things such as using renewable energy (and not relying entirely on the national grid, e.g.), producing food locally (instead of relying on world markets), mitigating and/or avoiding flooding in low-lying areas, using more low-carbon transportation methods (e.g., bike and pedestrian infrastructure) and in general becoming more self-sufficient. This is a major focus of the Transition Town movement [357], but cities, towns, and states/provinces all over the world have engaged in planning for resiliency. For example, the state of Colorado has its own Resiliency Resource Center [358], which is operated out of the Department of Local Affairs.
The video below summarizes a lot of these concepts and adds a few others. It also provides a few examples of permaculture.
Most of this reiterates much of what is written above, but there are a few more things I'd like to point out:
Hopefully, by now you have a solid understanding of what permaculture is, as well as its core ethics. Permaculture also has a set of 12 principles that should be used to guide all design decisions. The video below from Oregon State University provides a good overview of these principles, and examples of how they can be applied. You will not be expected to memorize them, but it will be helpful to have a general understanding of each.
Permacultureprinciples.com provides an excellent in-depth explanation [359] of each of these principles and also provides a ton of examples of each principle. If you want to explore any of the principles more (this is optional but strongly suggested if/when you have some time), including examples of concrete applications, click on the links to each item below. They even have a song for each principle, which is a nice touch! All quotes are taken from the permacultureprinciples.com site.
One other thing that I'd like to note before moving on is that while remembering and applying these principles takes a lot of effort, a properly designed permaculture system significantly minimizes effort once it is established! For example, a well-designed permaculture garden will require almost no active watering (it should be rain-fed), does not require the constant addition of fertilizers (it should be mostly self-sufficient), does not need pesticides (most pests should be eliminated by beneficial insects, chickens, or other natural biological solutions, and things like proper air flow and sunlight), and it minimizes replanting (true permaculture uses mostly perennials, not annual plants). A properly designed urban environment will optimize the use of local resources such as renewable energy, local food sources, and low-impact transportation. Such an urban system should also provide resources to help all people thrive, thus minimizing the need for social services.
Please note that people spend their whole lives researching and applying permaculture - we are only scratching the surface! But hopefully, you have a reasonably good understanding of what permaculture is and how it can be applied. The following is a brief summary of some key points:
Permaculture provides a practical framework for addressing food sustainability issues, but there are many other specific practices and concepts that can contribute solutions as well. See below for a description of a few of them. There are many more than this, but these are some that we may/will encounter when traveling.
Regenerative agriculture is closely related to permaculture, but not all permaculture food production systems are regenerative. As you might guess, regenerative agriculture refers to food growing methods that improve the natural environment, i.e., they regenerate local ecosystems. Terra Genesis International [372] provides a great synopsis of this concept. Note their use of the term ecosystem services. (If you are so inclined, they have more information on their site.):
Regenerative Agriculture is a system of farming principles and practices that increases biodiversity, enriches soils, improves watersheds, and enhances ecosystem services.
Regenerative Agriculture aims to capture carbon in soil and aboveground biomass, reversing current global trends of atmospheric accumulation.
At the same time, it offers increased yields, resilience to climate instability, and higher health and vitality for farming and ranching communities.
The system draws from decades of scientific and applied research by the global communities of organic farming, agroecology, Holistic Management, and agroforestry.
Common techniques include planting native crops that enhance biodiversity, using biochar to improve soil quality and sequester carbon, integrating animals and crops into a self-sufficient system, only using organic farming methods, and more. Like permaculture, regenerative agriculture recognizes that these systems will provide feedback and change over time and that farmers must be ready to adapt their systems as needed.
Community gardens are defined by the USDA [373] as "plots of land, usually in urban areas, that are rented by individuals or groups for private gardens or are for the benefit of the people caring for the garden." Community gardens can take on many forms, but the most common one consists of any number of individual beds (from a few to a hundred or more) that are tended by individuals or groups. Most community gardens are structured such that each bed is "rented" out for a nominal annual fee, and the renter manages their bed. Community gardens typically supply water and soil, and sometimes resources such as seeds and labor assistance. They are usually overseen by a manager, but they often host group events and expect individual gardeners to help out with tasks that benefit the whole garden community. These are most common in urban areas where residents do not possess adequate space to grow their own food but can be found in many other areas. They can be found all over the world. Most gardens have a set of rules governing them, such as the types of plants they can grow and what they can use in their beds (e.g., by only using organic growing methods).
Community gardens can also take the form of school gardens located on or near school property. They can be established in elementary, middle, high school, and college environments. The goals of school gardens usually include garden, food, and/or nutrition education, though many urban gardens provide this service as well. Therapy gardens are sometimes established so that they can be accessed by people with physical and/or mental issues, as gardening has therapeutic effects. Many gardens include initiatives to grow food to donate to local organizations such as food banks.
Research has shown that there are many benefits to community gardens, including but not limited to the following. (All links originally gathered from North Carolina State University Cooperative Extension [374]:
There are many more studies that demonstrate the benefits of community gardens. If you have ever participated in one, you would probably be able to list a few more! It is important to note that research shows that the benefits of community gardens are particularly pronounced in low-income areas, and thus are a recognized strategy to address equity and social justice (but also environment and economy!).
You may have encountered Fair Trade goods such as coffee or chocolate when food shopping, or perhaps at a coffee shop. A fair trade good usually has a distinctive logo such as the one below. The purpose of fair trade certification is primarily to ensure that the workers throughout the supply chain were paid a fair wage. These certifications are affirmed by third-party certifiers that have no affiliation with the product at hand. They investigate the entire supply chain of the product and certify the product if it meets their standard.
One of the most common certifiers is Fair Trade Certified [381]TM (I cannot show their logo due to copyright.) They list [382] the following four standards that must be met in order to obtain certification:
- Income sustainability: ...Our standards ensure producers, workers, farmers, and fishermen have the money needed to invest in their lives and their work.
- Empowerment: Fair Trade empowers people to make choices for the good of themselves and their community, regardless of gender, status, position in society, or position on the globe. Rigorous standards give farmers, workers, and fishermen a voice in the workplace and the community.
- Individual and community well-being: ...Our model is fueled by committees of farmers, workers, and fishermen who decide how to invest the Fair Trade Premium based on their community's greatest needs: often clean water, education, and healthcare.
- Environmental stewardship: ...Our standards work to keep the planet healthy for generations to come by prohibiting the most harmful chemicals and taking measures to protect natural resources.
As you can see, fair trade can address issues beyond providing living wages. Generally speaking, it is better to buy fair trade certified goods than non-certified goods, but it is best to investigate individual certifiers to ascertain how legitimate they are.
Merriam-Webster [383] provides a good definition of appropriate technology:
technology that is suitable to the social and economic conditions of the geographic area in which it is to be applied, is environmentally sound, and promotes self-sufficiency on the part of those using it.
The use of appropriate technology is a particularly important consideration when providing assistance to low income or otherwise marginalized communities. The idea behind appropriate technology is to make sure that any solutions proposed and/or aid provided is appropriate for the local conditions. These "conditions" can include local natural resources, but very often include local human capital, such as local knowledge, expertise, and physical capabilities. As indicated in the definition, it must promote self-sufficiency (which goes hand-in-hand with the first point).
For example, if a well-meaning organization travels to rural Mongolia or Peru to install a solar array and provide electricity, they must consider whether the locals that they are trying to help have the expertise to repair the system if it breaks down. Perhaps there is existing local expertise, or perhaps they need to be trained. Also, can they get replacement parts if they are needed? Are the solar arrays and components at risk for damage due to local wildlife or human populations? These are all questions that must be asked if self-sufficiency is to be addressed. One of the best ways to utilize appropriate technology is to work with the local populations to help them come up with solutions, instead of telling them what to do. Most likely they will have a wealth of knowledge to offer regarding the local conditions (they live there, after all!), but they likely also have experience trying to implement solutions.
The National Center for Appropriate Technology [384] in the U.S. provides a number of examples and explanations if you are so inclined. They work primarily with low-income populations in the U.S. to provide services such as energy assistance and sustainable, local food systems.
Here are some more site visits! Again, this is not required reading. I suggest browsing through them if/when you have time. This may help inspire your final project proposals!
By now you should be able to do all of the following:
You have reached the end of Lesson 9! Double-check the to-do list on the Lesson 9 Overview page [389] to make sure you have completed all of the activities listed there before you begin Lesson 10.
In the final full lesson of this course, you will learn some basics of Colorado geography (and geology), energy, energy policy, water, and water policy.
By the end of this lesson, you should be able to:
To Read | Lesson 10 Online Content | You're here! |
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To Do |
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If you have any general course questions, please post them to our HAVE A QUESTION discussion forum located under the Discussions tab in Canvas. I will check that discussion forum regularly to respond as appropriate. While you are there, feel free to post your own responses and comments if you are able to help out a classmate. If you have a question but would like to remain anonymous to the other students, email me through Canvas.
If you have something related to the material that you'd like to share, feel free to post to the Coffee Shop forum, also under the Discussions tab in Canvas.
Colorado is known as the "Centennial State" and is the 8th largest state [391] in the U.S. by area, at a little over 104,000 square miles. As a point of reference, it is over twice the size of Pennsylvania. However, it has only the 21st highest population [392], at just over 5.6 million people as of 2018. (Pennsylvania is 5th at around 12.8 million people.) The capital is Denver, which is known as the "Mile High City" because most of the city is at or above 1 mile above sea level. While known for its mountains, a significant portion of Colorado is part of the Great Plains and is nearly flat. Even the plains are at a high elevation, and in fact, Colorado has the highest average elevation of any state in the U.S. Colorado has more peaks higher than 14,000 feet (58 of them!) [393] than any state in the country. If you travel to Colorado for any amount of time, you will no doubt overhear discussions about these "fourteeners." It is nearly a universal pastime to climb fourteeners.
As you will read below, Colorado has a very diverse landscape and culture. It is known for the availability of outdoor activities (hiking, skiing, camping, white water rafting, biking, etc.), but also has an interesting mixture of modern and historic culture and practices. Farming and ranching are important to its economy and culture, but so are tourism, higher education, and high tech industries, among many other things. It is a wonderful state to explore!
As you probably recall, we will spend most of our time in Denver and Boulder, but will also drive through the mountains to the Western Slope town of Paonia. We will thus experience a variety of Colorado culture and scenery, from the Eastern Plains to the Front Range, as well as the Western Slope. More details on these regions below.
Colorado has many local regions and other geographic features [396], but the major ones that we will experience are as follows:
See the video below the image for a good explanation of how the Rocky Mountains and the Front Range formed. Note the explanation of why Red Rocks and other parts of the Front Range are sedimentary rocks (made from ancient sediments such as sand and silt) that were originally layered on top of the granite "basement" rock, and the Rocky Mountains themselves are made of granite that was pushed up via oceanic subduction. Some of this granite core is over 1 billion years old! (Side note: Geology is awesome!)
Please read the following sections of this article from Encyclopaedia Britannica [403]:
Another well-known feature of the state is the Continental Divide, sometimes referred to as the Great Divide. A continental divide is defined by National Geographic [404] as "a naturally occurring boundary or ridge separating a continent’s river systems. Each river system feeds into a distinct ocean basin, bay, or sea." As you can see in the image below, there are a number of continental divides in North America. Each of these lines is the boundary between two major drainage basins. The rivers and streams in each basin lead to a specific large body of water.
For example, the Eastern Continental Divide runs through Pennsylvania. Flowing water to the east of the divide ends up in the Atlantic Ocean, and west of the divide ends up in the Gulf of Mexico. In Colorado, water to the west of the Continental Divide flows to the Pacific Ocean, and to the east flows to the Gulf of Mexico (and ultimately the Atlantic Ocean). You may see signs while traveling through the mountains of Colorado like the one below that mark portions of the Continental Divide. There is also a trail that roughly follows the divide that is a national park - Continental Divide National Scenic Trail [405].
As the saying goes: "Whiskey's for drinking, water is for fighting." This is not far from the truth in Colorado! Water use and water rights are prominent issues in the state. It is an unusual experience for anyone that grew up on or near the East Coast, where the issue of water rights almost never comes up, to move to Colorado and find out that the "average" person is conversant in water rights. Water is such an important issue for Coloradans (and many who live in the western United States) because it is relatively scarce. As you can see in the maps below, most of the state receives under 20 inches of precipitation per year, and in fact, the average rainfall across the state is 15 inches per year, according to Denver Water [410]. This makes most of the state semi-arid, which means that it is climatologically not far away from a desert (arid) environment. As a point of comparison, most of the land east of the Mississippi receives more than 35 inches per year, with State College, PA receiving about 40 inches per year [411].
Further complicating matters is the comparison of the rainfall and population geographies of the state. Recall that the Western Slope of Colorado lies west of the Continental Divide and the Eastern Slope (including the Front Range) to the east. According to "Water Law" (Denver Water) [410], 10 percent of the state's residents live on the Western slope, but it contains 33 percent of the state's land and 70 percent of its water. Because of this, Western Slope water is often used on the Eastern Slope. This, in addition to relative scarcity and Colorado water laws, has contributed to water being a major issue in the state.
Please read the following summary of Denver and Colorado water policy. Read the sections entitled "Water law," "Water rights," "Rain barrels," and "Graywater use."
Colorado has a very diverse and often contentious energy landscape. For example:
While traveling through Colorado, it is not uncommon to see oil pump jacks, wind turbines/farms, fracking operations, solar arrays, and coal-fired power plants. (We will probably see more than a few of each during our time there.) Solar Energy International [308] has its training headquarters in Paonia on the Western Slope (we will visit them), yet fracking wells dot the local landscape and it is not uncommon to see train cars full of coal while traveling to and from Paonia. This variety can and does cause conflict, with fossil fuel advocates having strong disagreements with renewable energy advocates on personal and political levels.
The image below shows Colorado's 2014 fuel mix (the latest data available). You have seen this type of chart in EM SC 240N. Remember that this is called a "Sankey" chart and indicates energy flows. The numbers are all Trillions of BTUs (TBTUs) of energy, and the lines indicate the energy flows to different sectors. Remember that you read the chart from left to right, and can follow each primary energy source (the sources to the left) to see where they are used.
Energy policy can be very intricate and can vary significantly from state-to-state and even within states. If you are interested in finding out which energy policies exist in each state (and nationally), hands-down the best website for details is DSIRE [419], which is out of NC State University but is managed in conjunction with the U.S. Department of Energy. Believe it or not, DSIRE lists 125 energy policies [420] that apply to the state of Colorado! Obviously, we do not have time to go over all of them, but a few of the most prominent ones are below.
Renewable Portfolio Standards (RPSs) are created through legislation and require electricity providers to provide a certain percentage of their electricity from renewable (or alternative) sources. Each state is able to pass its own RPS law (or not), as there is no national RPS in the U.S. Each RPS dictates the percent targets compliance years (see below), and also indicates which energy sources can be used to meet the RPS goal.
Utilities must prove that the required percentage of the electricity they sell is from one of the eligible renewable sources. The three primary ways they do this is a) build and generate their own renewable electricity installations (e.g. a large solar array or wind farm), b) purchase renewable energy from a dedicated supplier (e.g. an independent owner of a large solar array or wind farm), or c) "take credit" for renewable electricity generated by customers on their grid. Utilities rarely build their own generation facilities nowadays (option a), but signing long-term contracts with independent suppliers is becoming very common (option b).
It is very common for utilities to "take credit" for customer-generated electricity, in particular through residential solar arrays. They do this by paying the customer a fee to take credit for the electricity they generate. Each credit is called a "renewable energy credit (or certificate)" (REC), though solar credits are often referred to as SRECs (solar renewable energy credits). REC and SREC prices are set by different mechanisms, but usually, they are sold on the open market. There are too many details to go into here, but here is an example of how this could work: Let's say I have a solar array and I generate 1,000 kWh of electricity in a year (this is 1 MWh of electricity). If the utility agrees to pay $50/SREC, then they would pay me an additional $50 at the end of the year. If I generate 2 MWh, I would get $100, and so on. This is in addition to me not having to pay for the electricity that I generate! In other words, if I generate 1,000 kWh, that is 1,000 fewer kWh that I have to pay the utility for. (This is referred to as net metering.)
RPS benchmarks gradually increase, e.g. 5% in year one, 7.5% in year two, and so on. If a utility does not meet the benchmark in a given year, they are penalized (usually fined).
For example, Colorado passed an RPS in 2004. Details can be found here [421]. Some details relevant to the discussion above are as follows:
A tax credit is just that, a credit. When an individual or business investor earns a tax credit it means that the amount of the credit will be subtracted from a future tax bill. In the United States, we have a Federal Residential Renewable Energy Tax Credit [423] which provides a tax credit covering 30% of the cost of installation. This is commonly referred to as the investment tax credit or ITC. If you put a photovoltaic system on your roof at a cost of $30,000, you earn a $9,000 tax credit. The government doesn’t mail you a check for this amount. It means you get to deduct that amount from your next tax payment. To realize this money, you will need to have paid at least $9,000 in taxes, but excess credits can "generally" be carried over to future tax years. Note that even if you were owed a refund, this tax credit can be used to increase your refund, as long as you paid at least $9,000 in federal income tax throughout the year. Eligible energy sources include "solar water heat, solar photovoltaics, geothermal heat pumps, wind (small), [and] fuel cells using renewable fuels." This is only applicable to residential customers. The percent credit will gradually decrease after 2019 and zero out at the end of 2021 (unless an updated law is passed).
Essentially the same ITC (but it is technically the Business Energy Investment Tax Credit [424]) applies to corporate owners in the following sectors "commercial, industrial, investor-owned utility, cooperative utilities, and agricultural." So basically everyone except for residential, and non-profits. The incentive levels are a little different for some of the energy sources, but solar, wind, and fuel cells earn a 30% credit in 2019, which then decreases at the same rate as the residential ITC afterward.
A production tax credit (PTC) [425] provides an incentive for each kWh of renewable electricity generated and is not based on the up-front cost of the technology. This is a federal incentive. For any source installed in 2018, the only technology that is eligible for a PTC is wind, and qualified facilities will receive about 0.8 cents ($0.008) per kWh generated, but this price is guaranteed for 10 years after the turbine begins service, so the savings can add up! For example, a 2 MW turbine with a 40% capacity factor would generate the following revenue:
A 2 MW turbine is actually on the smaller end of new wind turbine sizes, so even a seemingly meager PTC can be a big deal!
Again, these are only a few of the many, many energy policies that apply to the State of Colorado! This will help provide some context for our experience there, and knowing where to access energy policy information will be helpful for your projects.
By now you should be able to do the following:
You have reached the end of Lesson 10! Double-check the to-do list on the Lesson 10 Overview page [426] to make sure you have completed all of the activities listed there before you begin Lesson 11.
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