Module 1: Why Energy Matters
Module 1: Why Energy Matters
Overview
We will get to the facts and figures soon enough, but in Module 1 we will start with stories of our ancestors showing the immense value, but real difficulties of energy use.
When drought strikes, people who can drill wells, pump water and trade for food are much better off than people without diesel pumps and trucks. Drought ended the civilization of the Ancestral Puebloan people of what is now the southwestern United States but was much less damaging to the people of Oklahoma more recently. However, before diesel, gasoline, and other fossil fuels, we often burned whales and trees much faster than they grew back, causing real problems.
Within this module, the focus is to get you thinking about the value of energy, and how difficult getting that energy can be—both historically and currently.
Note that we do not expect you to become experts on ancestral Puebloans or Oklahomans—they serve as examples. We could have told similar stories from China, or Europe, or Guatemala, or many other places with many other people. This is really about all of us.
Goals and Objectives
Goals and Objectives
Goals
- Recognize the natural and human-driven systems and processes that produce energy and affect the environment
- Explain scientific concepts in language non-scientists can understand
- Find reliable sources of information on the internet
Learning Objectives
This unit is mostly about helping you see how much good we get from energy. By the end of this module, you should be able to:
- Recognize that even really smart people have failed when climate changed
- Explain how machines and trade have helped other people avoid catastrophe
- Describe how we have burned through energy sources in the past
- Show that people can make money and save the world at the same time
Roadmap
| To Read | Materials on the course website (Module 1) Get Rich and Save the World [1] |
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| To Do | Module 1 Discussion Post Module 1 Discussion Comments Quiz 1 |
Due Wednesday Due Sunday Due Sunday |
Questions?
If you prefer to use email:
If you have any questions, please email your faculty member through your campus CMS (Canvas/Moodle/myShip). We will check daily to respond. If your question is one that is relevant to the entire class, we may respond to the entire class rather than individually.
If you have any questions, please post them to Help Discussion. We will check that discussion forum daily to respond. While you are there, feel free to post your own responses if you, too, are able to help out a classmate.
Unfriending Fossil Fuels
Unfriending Fossil Fuels
Fossil Fuels have become our best friends—oil, coal, and natural gas power about 85% of the global economy. These energies are absolutely essential today to keep us healthy and happy. Seven billion people inhabit the planet—a planet with whales in the oceans and trees on the land—because we have mostly switched from burning trees and whales for energy to burning fossil trees and fossil algae.
But, we are burning those fossils about a million times faster than nature saved them for us. We cannot continue these practices very far into the future because the resources will no longer be available. If we burn most of our available resources before we make major progress on sustainable alternatives, we risk dangerous shortages of energy in a world that is much harder to live in because of damaging climate change. Given this, we are faced with the difficult task of "un-friending" our best friends—fossil fuels.
According to the “Help” page on a major social networking site, "un-friending" someone is as simple as going to the right website and clicking “Un-friend." Even that simple act has generated a truly amazing number of online discussions that explore the implications, reasons, impacts, options, and ethics of "un-friending." Switching from fossil fuels is far more serious, as it involves changing how we spend almost $1 trillion per year just in the U.S., for example.
To begin, let’s take a quick tour of just how valuable fossil fuels are to us. Later, we will look at the dangers of continued reliance on fossil fuels. Looking at the good and the bad of fossil fuels will help us make sense of the issues at hand.
Required Reading
Get Rich and Save the World [1] is an article by Dr. Richard Alley from the Earth: The Operators' Manual website. This will give you more background before moving on to the next section in this module.
At the end of this module, you will be asked to join in an online discussion of the module content with other course participants. You may access the Week 1 Discussion Forum at any time, but we suggest that you work through all of the content first so you are ready to fully engage in the topic-related discussion(s).
Dealing with Drought
Dealing with Drought
Short Version: Drought or other natural disasters can cause even really smart people to fail badly if they don't get enough help. However, with plenty of fossil-fueled tools and trade, the dangers of natural disasters have been reduced greatly. Here, we consider two cases of people responding to severe droughts — one before the age of fossil-fuel energy, the other during the age of fossil-fuel energy.
Friendlier but Longer Version: We could tell many stories about the benefits of fossil fuels. Here is one. The details of this story are not especially important, but the basic idea is greatly important—our ability to use fossil fuels to power our tools makes us much better off.
A few years ago, a great group of Penn State students, faculty, and film professionals toured many of the national parks of the US southwest. We hiked to the bottom of the Grand Canyon, rafted the Colorado below the Glen Canyon dam, slept on the slick rock at Canyonlands, and otherwise had a truly wonderful trip.
Many of us were especially fascinated by Mesa Verde. Ancestral Puebloan (often called Anasazi) people lived at that site for roughly 700 years—much longer than the history of the Americas since Columbus—first on top of the mesa, but then moving to build intricate dwellings in caves down the mesa sides, commuting up ladders and steps carved in the rock to work the fields on top. But, after most of a millennium, the people left.
Archaeological sites are almost always open to interpretation and argument. We know what was left behind, and we can learn much of what was going on around the area, but the record is necessarily incomplete and viewed through the lens of who we are.
Still, much of the Mesa Verde story is rather clear. The national park rangers showed us the little holes that the people painstakingly carved in the rock in the dwelling caves to capture a trickle of water. We marveled at the carefully constructed check dams, stones set to stop the erosion of the mesa top and catch a little soil and water to grow a little more corn. Food-storage structures were built in places that were very difficult to reach. And, toward the end, windows between different parts of the cliff dwellings were blocked with rocks, dividing people.
Video: Mesa Verde Story (8:29)
MESA VERDE
DR. RICHARD ALLEY: This is a wonderful, but a little bit disturbing, story of some really smart people living in southwestern Colorado, ancestral Puebloans, at a place called Mesa Verde. They lived there for hundreds of years and left shortly before Columbus got to the New World. A lot of their farming was done on top of a mesa, and they lived in caves down the side of the mesa in these wonderful structures made mostly out of stone. Here is a modern ladder with a person for scale.
And what I want you to notice here, in addition to the great buildings, is up here on top. This fairly clearly was a granary-- this is where they kept their food late in their existence there. It's probable, not certain, but it's probable that this is a little bit like a modern person putting the cookies way up on the upper shelf, so they won't eat them before they're ready to. Accept this wasn't the cookies, this was the food. And that might be something you'd do if food was really getting scarce.
CAVE
Now that structure we just looked at, if you go behind it, you find it's actually built in a cave. And this is sandstone, and there's a little bits of shale and water sort of percolates down through here. And then it hits the shale, and it seeps out. So, it's a little bit damp back there, in a generally dry climate.
WATER
And if you look around back here on this rock, do you see? You see things like this-- little holes they dug in the rock so that when water came seeping out, it would fall into these holes, drip in, and you could take a cup and get a little bit of water. And that's what you do if you're really thirsty because that doesn't look like the best water for us. But if that's all the water you have, that's what you do.
WINDOWS
Now they built these wonderful structures, and some of them had windows between, say, your house and mine, or your room and mine. And late in the occupation, it appears that they walled the windows off. And usually, when you're walling the window off, you're trying to keep something out. And it is possible that they were not getting along with their neighbors quite as well as they might once have if they're walling off the windows within the structure.
CORN DAM
Now if you go up on top where they grew the corn, this actually was built by the ancestral Puebloans, hundreds of years ago. And it stops erosion. So, there's a little tiny stream comes through here, but this little dam of rocks catches a little bit of soil, where you could grow a little bit of corn. And it traps a little bit of water, and a little bit of soil. And so, you're looking at people that really were shepherding what they had, conserving. And apparently, they needed this.
STRUCTURES
What you see then, is people who were living on the edge. Hard to get enough food, hard to get enough water, life was getting hard. If you look around the structure, it's mostly made of stone, because there weren't many trees. But there's a little bit of wood in the houses there at Mesa Verde.
WOOD
If you know anything about wood, you know that it has layers. And the layers, when the tree is happy, it grows a thick ring. And when the tree is unhappy, it grows a thinner ring. And you can see different thicknesses of rings in this.
And you can take cores, and you can count the layers, and count how thick the layers are. And in a place like Mesa Verde, where it's very dry, a happy tree is one that has rain. And an unhappy tree doesn't.
It's also possible, if you have a living tree, you can take a core from it, and you can see the pattern of thick and thin rings in that core. There might be dead trees nearby, and you can see the pattern of thick and thin rings in that, and you can match them up between trees. And you can go back to the wood in the archaeological sites, and you can find the same pattern. And so, you can make a tree ring record, which is longer than the life of any given tree, with the thickness of the ring telling you how much it rained.
So, now what can you do? Archaeologists and tree ring people got together. And they made the plot that you're going to see here. The year 800 is on your left, the year 1200, 1300 there, which is sort of the crash.
And so first of all, you have in green here, a history of how many people could live in the area. And this is actually done just down the road from Mesa Verde, at a place called Long House Valley that had less trade, so it was easier to work on. And what they did is they looked at the trees, and they said how thick a layer is, is how much it rained.
Rain also tells you how much corn could be grown, and corn is how many people could live there. So the green curve is from trees and from knowledge of the people-- how many people could live in this place. Independently, archaeologists went in, and they looked at the classical things-- how many people were living there? You know, how many burials, and how many houses, and that sort of thing. And so, they looked at how many people were living there, and that's this curve.
And what you'll notice is within the scientific uncertainties of all this, these are the same record. How many people lived there, and how many people could live there, are essentially the same. When it got wet, population went up. When it got dry, we don't know whether they died, or whether they left, or whether they quit having babies. But the population went down.
And the rains came back, and so did the people. And then the rains left. And at some point, the people said, we are out of here. We're going to become environmental refugees, and we're going to go someplace it rains more. And they left.
And so, these are very smart people, doing amazing things. But they were controlled by the climate, ultimately. And it got them in the end.
OKLAHOMA
Now, this is more recent. This is Oklahoma from the year 1900 to the year 2000. And the red curve here now is a history of drought.
And down is really dry, and this thing right down here is the Dust Bowl. And that made great literature, but it made lousy living, and you've probably seen the pictures of the Okies headed for California to get away from the dust. But look at the population history of Oklahoma, and you'll see that while the Dust Bowl kicked them-- and then World War II, some probably going off to war-- it's not nearly the disaster it was for the ancestral Puebloans.
Now, these are also smart people, but these are people that when the drought hit, some of them got in gasoline-powered cars and they drove away. But some of them had food delivered in gasoline-powered cars, or in diesel-powered trains. They had diesel-powered well drilling, that they could drill a well, and they could run motors, or run windmills to pump water out. And so, they had more tools, and they had more stuff-- and those were fossil-fueled.
And more recently, when other droughts have occurred, it really hasn't affected the population much at all. Little tiny changes, but really not too much. And so, what you can see is our having fossil fuels, and having machines, and having trade has greatly insulated us from what otherwise would be disasters for even very smart people.
Credit: Dutton Institute [2]. "EARTH 104 Module 1 Mesa Verde [3]." YouTube. November 18, 2014.
Some of the evidence we saw at Mesa Verde of people dealing with hard times caused by a drought.
The evidence is very clear that the people were conserving water and soil, working to maintain and improve their ability to grow food. The hard-to-reach food storage might be a truly serious version of someone hiding something on the top shelf so they don’t eat it before they should, and the window-blocking is at least suggestive of increasing social stresses.
The image is divided into two sections. On the left, there is a close-up photograph of a tree cross-section embedded in a rock matrix. The cross-section shows several concentric growth rings, with a rough texture and visible cracks spreading from the center outward. The coloration varies from light to dark brown, giving it an aged appearance.
On the right, there are two smaller images. The top one depicts a smoother cross-section of a tree ring, showing clearer concentric rings in vivid shades of brown and orange, with less visible cracking. The lower image displays a horizontal wooden beam with a small exposed cross-section in the middle, indicated by a blue arrow pointing at it.
To learn more of this story, scientists went to Long House Valley in Arizona, a simpler place nearby that was occupied by the same people. Recall that the age of a tree can be learned by counting its yearly rings. These rings are easy to see in places where there are pronounced seasons because trees grow rapidly during the spring and early summer, putting on a lot of new wood that appears lighter in color, and then during the fall and winter, the growth slows way down and very little wood is added; this late-season wood is denser and darker. So, one thick light band and a thin darker band make up one year. This is sometimes not the case for trees that grow in the tropics, where there may be little difference between summer and winter, however, if tropical settings with defined wet and dry seasons, trees do develop annual rings. The important thing is that there needs to be a seasonality for trees to develop annual rings. In the dry climate of a place like Long House, trees grow better when it is wetter in the growing season, so a tree will thicker annual rings — the ring thickness is directly correlated to the amount of rainfall. In colder climates, the ring width can be correlated to temperatures during the growing season — warmer temperatures lead to thicker rings.
Thus, tree rings preserve a record of the climate history — rainfall in drier regions and temperature in colder regions. And, living trees overlap in age with trees that were used in construction, or trees that died but haven’t rotted yet. Using the pattern of thick and thin years to match the modern and older wood (a technique called cross-dating), the history of rainfall can be extended beyond the life of a single tree. Cross-dating has enabled us to produce continuous tree ring records that go back about 12,000 years even though the oldest living tree is just a bit over 5,000 years.
Rain and Population
Rain and Population
Rain can grow corn as well as trees, and corn can grow people. Thus, knowing something about trees, corn, and people, a team of scientists can start with tree rings and learn how many Ancestral Puebloan people could have lived in an area. Meanwhile, archaeologists are able to use their techniques of digging and dating to learn how many people actually lived in an area. Teams of archaeologists and tree-ring climatologists did this research at the “end of the road” in the small, remote Long House Valley, which was not a trading center.
What they learned is striking, as shown in the figure.
Next, take a look at a similar history, from Oklahoma over the last century. The Dust Bowl of the 1930s was a major drought, made worse by various economic decisions about land use. Wonderful literature documents the terrible economy and environment, as people suffered and died.
Yet, even today, where the economic resources are not available, as in the African Sahel, droughts have huge consequences and drive widespread starvation or migrations of environmental refugees.
Every person I ever met who studied the ancestral Puebloan people of Mesa Verde and surroundings has come away deeply impressed with the resourcefulness and cleverness of the people. The difference between Puebloan and Oklahoman success during drought is not because one group was smart and the other wasn’t. But the technologies and trade are vastly different (for many reasons!), and the people who could call on more tools and more help were more successful. Some of those tools were wind-powered, but most ran on fossil fuels, and success has increased as the use of fossil fuels increased.
Want to know more?
Take a look at the Enrichment called Burning for Learning
Running Out of Trees
Running Out of Trees
The early European settlers in central Pennsylvania (and many other places) wanted iron, turning rusty soils into pig iron in dozens of different furnaces (including Pennsylvania’s Centre Furnace, just down the hill from Penn State’s University Park Campus, where this is being written), and then turning the hunks of iron into useful things in forges (including Pennsylvania’s Valley Forge).
Video: Days of Iron (2:10)
Dr. Richard Alley: This is a Centre Furnace. The road runs up the hill to Penn State University Park campus and the town of State College. But State College didn't even exist when the university was founded in 1855. The university was built up the hill from the Iron Furnace, and they've been making iron here since 1791.
This is a glass slag. This is what was left when they melted the ore to get the iron out and drained that away and then this chilled, and it froze to make the glass. Melting the ore took energy. And the energy came from charcoal, and the charcoal came from trees. To fire a furnace for a year took more than a half a square mile of trees. But the furnace was served by an independent community, and it had people in it who built houses and heated them in the winter and cooked, and that took wood too.
Running a furnace and what was around it, took a square mile of trees a year. And there were lots of furnaces and lots of forages, like Valley Forge, that turned the iron into useful things. The furnace closed in 1858. Production moved west to use better ores and to use coal as a fuel because the trees were gone. It was about the same time as peak whale oil, and just before the first modern oil well up the road here in 1859. Today, we have whales, and we have trees because we burn fossil algae and fossil trees, oil and coal, and natural gas.
Pennsylvania by itself had dozens of iron furnaces. The early iron furnaces and forges were fueled by charcoal, which was made from trees. As many as 100 workers would spend fall and winter making the charcoal for just one furnace, which used trees from more than half a square mile (more than a square kilometer) per year. Those people were burning a lot of trees in their fireplaces in winter as well, and the forge that converted the pig iron to useful things required as much charcoal as a furnace. Thus, forests and iron-making didn’t coexist for very long—the Commonwealth of Pennsylvania was rapidly converted from “Penn’s Woods” to the “Pennsylvania desert”, with almost no trees or wildlife remaining. You can see this deforestation in the US in the form of some maps [7]. And it wasn’t just Pennsylvania, or just Europeans—the growth of the iron industry in China led to deforestation, too, and many other people around the world have cut trees much faster than they grew back.
Running Out of Whales
Running Out of Whales
The flickering light of a fireplace or wood stove isn’t great for reading in a dark Pennsylvania winter, so people have burned many other things for light. In Pennsylvania and elsewhere in the US, wealthy early European settlers preferred burning whale oil, which didn’t stink like tallow candles (made from animal fat), and didn’t blow up like the alcohol-turpentine mixture known as camphine. At its peak, the Yankee whaling fleet had 10,000 sailors on ships, scouring the far reaches of the ocean for whales to supply oil. Populations of the main species pursued by the Yankee whalers dropped precipitously, and the Yankee production of whale oil followed, with prices rising greatly, from a low that would be about $7/gallon today, to a peak of almost $25/gallon. The total amount of whale oil collected by the Yankee whalers in the 1800s is roughly the same as the total amount of oil (petroleum) imported by the United States in a week—if we hit a shortage of our modern energy sources, we cannot easily go back to our former sources!
Video: Whales Celebrate Oil in Pennsylvania (0:48)
DR. RICHARD ALLEY: This is an editorial cartoon that was published in the magazine, the publication, Vanity Fair in the year 1861, just before the US Civil War. And it is the grand ball given by the whales in honor of the discovery of the oil wells in Pennsylvania. And you'll notice the whales in their evening dress being served by frogs. And it's just before the Civil War, so you have the oil wells of our native land, may they never secede. And you have oils well that ends well. And we whale no more for our blubber. We have whales because we burn fossil algae. We don't burn whales to see at night anymore.
As the US got out of the whaling business, others—particularly Norwegians—got into it, using new technologies including faster boats and harpoon cannons to hunt species that had eluded the Yankee whalers. But even the vast resource of fast Antarctic whales proved small compared to the hunger of humans, and soon those whales were depleted as well.
Video: Peak Whale Oil (2:16)
DR. RICHARD ALLEY: This is the history of whale oil production from the Yankee fleet from New England in the United States from the year 1800 on your left to the year 1880 on your right. And you'll see that they got better and better at whaling. And then, they went over peak whale oil and down the other side.
A lot of this was things like there's a civil war over here, when some whaling ships were sunk to block Southern harbors. The whaling fleet is crushed in the ice off of Alaska over here, and insurance prices go through the roof. But they were up off of Alaska because they couldn't find whales anywhere else. And that's what was going on.
Now here, there are 10,000 men on ships out of New England looking for whales in the world oceans. And there's lots more people working in New England to process the whale oil and what have you. Because you kill the whale and you boil the whale to make the oil, but then all the pieces of the whale were used for various things.
Now, as they get better at whaling, the price went down. And the low point here is about 7 dollars a gallon for whale oil that was used in lamps. As soon as peak whale oil wash it, the price of whale oil went up to 23 dollars a gallon. And this is the equivalent of modern money.
And so, what you find is it's not when you run out of the resource that the price goes up. It's as soon as the resource starts to get scarce. Now indeed, the free market worked in some sense. People went up the road from where I'm speaking to you and they drilled the first modern oil well, the Drake Well, in 1859. But you'll notice even that didn't really bring the price back down.
All of this oil-- 100 years of whaling-- 10,000 men at the peak-- collected as much whale oil as about one week of modern US oil imports. So, there's really no chance that we can actually go back to the way we used to do things.
Video: Polka Oil (0:47)
DR. RICHARD ALLEY: This is actually the cover of a piece of sheet music that was published in 1864 in New York. This is "The American Petroleum Polka," or charge, or gallop, or waltz, or march. And it has a picture of a beautiful Pennsylvania scene, the oil well spouting its oil. Now oil was black back then. Oil is still black. But you couldn't have black oil falling on the lady's pink dress, so they made the oil white. And then bragging, "This oil well threw pure oil a 100 feet high." people understood the value that you get from oil, from petroleum. And they celebrated that.
The first modern oil well was drilled in Pennsylvania along Oil Creek, up the road from where Dr. Alley lives, in 1859, shortly after peak whale oil in the US and the sharp rise in whale-oil prices. The impact was understood even then, with the magazine Vanity Fair in 1861 publishing an editorial cartoon showing the “Grand Ball of the Whales in Honor of the Oil Wells of Pennsylvania”, featuring the sign “Oils well that ends well”. The cover of the 1864 sheet music American Petroleum Polka features a Pennsylvania scene including a lady in a pink dress and an oil well that “…threw pure oil 100 feet high” (30 m).
Earth: The Operators' Manual
Video: America's Energy Past: A 3-minute clip on "peak whales".
NARRATOR: But to have a sustainable energy future, we have to do things differently than in the past. Richard Alley explains--
DR. RICHARD ALLEY: We've been burning whatever was at hand for a long, long time. But as we see repeatedly with energy, you can burn too much of a good thing. And there are patterns in the human use of energy and if we're stupid enough to repeat them, burn all the fossil fuel remaining on the planet and put the CO2 into the air, we will cook our future.
Take what we did to trees in North America, for example. When the first settlers arrived on America's east coast, the forests were so thick, you could barely see the sky. That soon changed. And the forests almost completely disappeared as more and more trees were cut down to meet the heating, cooking and building needs of a growing population. Making iron needed lots of furnaces and the furnaces ran on charcoal made from trees.
You can trace that history in tell-tale place names from my home state of Pennsylvania. So farewell virgin forests, hello Pennsylvania Furnace, Lucy Furnace, Harmony Forge, and Valley Forge of Revolutionary War fame. Large areas of forest were soon depleted, and charcoal making and iron production moved on, to repeat the process elsewhere. Peak Wood, meaning the time of maximum production, came as early as the first decades of the 19th century or even before that for some parts of the East Coast. The pattern of using up an energy resource until it was nearly gone was repeated at sea.
As America's population grew, so did their need for a better way to light the night. So whaling crews went to sea, on the hunt for the very best source of illumination... whale oil. At first, large numbers of whales were found nearby. They could just be towed to shore. But by the 1870s, we'd burned so many whales to light our evenings, that all the easy whales were gone. Whale-oil prices roughly doubled. Now, ships had to travel close to the poles in search of bowhead whales. Their oil wasn't as good. And conditions were really dangerous. In 1871, up in the Arctic, 33 ships were trapped in the ice and crushed. Just as happened with America's forests, we'd exploited the most easily accessible resources and hadn't stopped until we'd almost used them up. Lucky for us, in 1859 a cheaper and more abundant source of energy had been discovered with Edwin Drake's successful oil well, drilled in Titusville, Pennsylvania. And for 150 years, America ran and grew on oil and coal.
Discussion Assignment
Reminder!
After completing your Discussion Assignment, don't forget to take the Module 1 Quiz. If you didn't answer the Learning Checkpoint questions, take a few minutes to complete them now. They will help your study for the quiz, and you may even see a few of those questions on the quiz!
Discussion Question
Objective:
Show that people can make money and save the world at the same time. Find an article online about someone who has made money by doing something that conserves energy or generates energy in a new way that is less damaging to the Earth than traditional fossil fuel extraction and burning. Share it with the other students in this course and discuss the various ways entrepreneurs have approached this issue.
Goals:
- Find reliable sources of information on the internet
- Communicate scientific ideas in language non-scientists can understand
Read:
Get Rich and Save the World [1] from Earth the Operator's Manual
Description:
Many of us pessimistically accept the idea that in order to make money and progress, we have no choice but to inflict some amount of damage on the Earth and its environment. But there are those out there who have flipped this axiom on its head by finding ways to make money by doing things that help the Earth. For this activity, search online for an article to share with the class. The article should describe one way in which someone or some company has found a way to make money by saving energy or by developing new alternative means of producing energy.
Start by searching the terms "energy entrepreneurs" or "environmental entrepreneurs". Click around until you find something interesting.
Once you find an article you would like to share, write 2-3 sentences summarizing the content. Then, write an additional 1-2 sentences explaining your thoughts on making money and helping the world. Explain in your own words why you think it is or is not possible or necessary to implement these ideas on a global scale.
Instructions:
Your discussion post should include a link to the article you have chosen, a summary 100-150 words in length, and a personal commentary 75-100 words in length. Your original post must be submitted by midnight on Wednesday. In addition, you are required to comment on at least one of your peers' posts by midnight on Sunday. You can comment on as many posts as you like, but please try to make your first comment to a post that does not have any other comments yet. Once you have an idea of what you want your post to be, go to the course discussion for your campus and create a new post.
Scoring Information and Rubric:
The discussion post is worth a total of 20 points. The comment is worth an additional 5 points.
| Description | Possible Points |
|---|---|
| link to appropriate article posted | 5 |
| summary provides a clear description of the article content (100-150 words) | 10 |
| well-reasoned comment on your own article included in your post (75-100 words) | 5 |
| well-reasoned comment on someone else's article and post (75-100 words) | 5 |
Summary and Final Tasks
Summary and Final Tasks
Summary
Our history is thus quite clear. Life is hard if we have to do everything for ourselves. We rely on arranging for help, getting energy from outside us. As we have learned to hunt, gather and control energy, we have gained the ability to survive droughts, cold, and other problems that might have defeated us before. But, even for resources such as whales and trees that can grow back, we often over-harvest until they become scarce (or disappear entirely, as we have done to many species such as the wooly mammoths of ice-age North America). When we switched to heavy use of fossil fuels, we reduced our reliance on some of the earlier sources—we have whales and trees today because we rely on burning oil, coal and natural gas.
Reminder - Complete all of the Module 1 tasks!
You have reached the end of Module 1! Double-check the Module Roadmap table to make sure you have completed all of the activities listed there before you begin Module 2.
Enrichments
Use the links to go to the enrichments for Module 1. These materials are not required and will not be covered in the assessments, but they are interesting and will add to your understanding.
Burning for Learning
Do you ever empty the lawn-mower bag to get your dinner? Or chew up a handful of wheat or leaves from the maple tree? How about raw meat?
Cows can succeed by eating grass, but they have four stomachs and spend a lot of time “chewing their cud” to help break down the grass to be digested. Caterpillars can eat wheat or maple leaves, but a whole lot of a caterpillar is a digestive tract. And many predators eat raw meat.
But, we don’t do any of these things. We have mastered the art of using fire to cook our food. This kills parasites, but it also starts the process of digestion. We don’t have the type of digestive system that would allow us to get enough energy out of leaves and grass or “raw” wheat and raw meat, to keep us active enough to grow, harvest or catch those foods in the wild. If you are dieting to lose weight, eating raw vegetables is a great idea; if you are trying to survive the winter as a fur trapper in some remote part of the Yukon, you might look for something that supplies a bit more energy.
Fire may be the big difference between humans and other primates. If we didn’t cook, we wouldn’t get enough energy from our food to supply our big brains. Instead, we’d need a bigger or longer digestive system to process leaves and seeds and roots and raw meat, but the extra digestive system would use up a lot of the energy it extracted from such things to keep itself alive, with not enough energy left over to support all the extra gray matter between our ears. We really may have needed to burn to learn!
We’ll probably never know for sure whether fire was really required for us to survive as humans, but there is no question that it makes life easier in many ways. Staying warm in an Arctic winter is much, much easier with a fire than without one. Fire helps in scaring away predators, killing bad things in food, and more. For example, the native people of the eastern US grew corn, beans, and squash in clearings in the forest. Chopping down trees with stone axes is not easy; “girdling” by cutting the bark will kill the trees, and fire can then be used to clear the land and keep it clear. (Slash-and-burn agriculture is not a new invention!)
Burning wood is just one of the ways that we humans use to get someone or something else to do some of our work for us. Rather than being limited by the energy we can get from our metabolism (the food we “burn” inside of us), we get lots of extra energy by burning other things outside of us. We burn coal, natural gas, and petroleum to generate most of our electricity and power our machines. We all use this energy, and our share of it is something like 100 times as great as the energy we consume in the form of food! So our external energy use is far greater than our internal energy use from food.
Shortly after the last ice age ended, hunter-gatherers in many parts of the world began settling down and developing agriculture. This switch to growing food may not have been possible during the highly variable climate of the ice age. This switch helped fuel a major growth in population that continues today. But, by many measures, the switch also caused the new farmers to become less healthy, eating a less varied diet and suffering from more diseases-disease organisms and parasites enjoyed it when their human hosts settled down close together, making it easy to cause more sickness! You will find LOTS of ideas about why our ancestors settled down and started growing crops. One big possibility is that the world was nearly full of hunter-gatherers-the good places for finding something to eat were already taken, people died in marginal areas during bad years, people didn’t want their children to die, so they developed a new “technology” to feed themselves.
Very few people today have spent enough time with a shovel or hoe to know how difficult agriculture can be, even with modern tools. Plowing and cultivating are hard work. So, perhaps as early as 8000 years ago, people were figuring out how to get oxen to pull plows. This was NOT an easy undertaking, requiring selective breeding to domesticate wild creatures, then feeding those creatures and protecting them from predators and keeping them from running away, and inventing yokes and plows and convincing the oxen to wear the yokes and pull the plows. Yet all of this effort and more was easier for early agriculturalists than actually doing the digging themselves. Once again, people were getting ahead by getting something else to do their work for them.