NARRATOR: The first thing to do in this capstone project is to find a carbon emissions scenario history that keeps the global temperature down below three degrees. So this model comes loaded with this carbon emissions history here, which is the red line here. And you can see that if you look at the plot here the temperature actually rises too high in the center area, 4.5 degrees. So you go in and you change this. Let's lower this emissions history. We'll do something like this. Doesn't matter how, we're just fiddling around here.

OK, and then you run the model like that and see what happens. And so it looks like here we've kept the temperature-- we're getting a little bit closer here, so 3.22. Still too high in the emissions. So you have to adjust the emissions history until you get the global temperature down below three degrees warming. And then once you've done that, you want to make sure that this emissions history has left us with enough fossil fuels that we could continue this level of emissions for a specified period of time.

So all you have to do there is to take the total amount of fossil fuels left over, and that would be this pink curve here. It's the second time I ran the model. We were left with 2,400 gigatons of carbon, which is quite a lot. And if we were to look at the final emissions right here at about two, so with this rate of burning, two gigatons of carbon per year, we've got 2,400, we've got about 1,200 years of time. So we definitely have left ourselves plenty of fossil fuels, so we can rely on them to a limited extent for a very, very long time indeed. So this is an OK and acceptable scenario from that standpoint.

So this is step one of this process. Once you've done this, you go on to step two and there will be another video that will explain how to do that.

PRESENTER: In Step 2 of the Capstone Project here, we have to make some decisions about the mix of different fossil fuels that we're going to use as our carbon-based energy. And so, the model comes with this little pie diagram, it's showing the present-day distribution of coal, natural gas, and oil. So those are the percentages, or fractions really. And so, you can change this. You can keep this the way it is, or you can reduce it. But if we reduce it, we can maybe get this fossil fuel energy intensity number little bit higher. So, this is the number of exajoules of energy you create per gigaton of carbon emissions. Remember, we've already sort of set, we've determined, in this graphical converter what the carbon emissions are going to be.

And so, the question is, well, how much energy can we get from that, that amount of carbon emissions? That, this is in gigatons of carbon. So, this fossil fuel energy intensity value, the bigger this is, the more energy you get from that. And depending on, because they cost different amounts per unit of energy, we're going to end up with a different fossil fuel unit cost. So, you can see presently it's 18 dollars and 5 cents, not dollars and five cents but it's in, its billions of dollars per exajoule of energy, let’s say. We're going to make some changes here. We’re going to make these changes by sliding these little yellow, or these white circles around, like that. We can, so we can make natural gas a bigger part of this.

Now I'm going to do something radical here and say, I'm gonna just kinda cut coal out entirely. There, I've cut coal to zero. Natural gas I’ve got that at 73. I'm going to bump that up to closer to 80. That's close enough. Now, if I run the model, you will see the unit cost and the fossil fuel energy intensity change. So, we’ll just run the model. You see those values change. So sure enough, I got this up higher, close to the, theoretically this could be as high as 59.

So, I'm quite close here. I've kept some oil here in the mix, and it's just because the products of oil, so, gasoline, diesel, kerosene, jet fuel, things like that. Those are, those are pretty useful. They're very portable forms of energy. So, we might want to still have some use of oil, but for most of the other carbon energy, we're going to rely on natural gas, which is cleaner. And sure enough, that brings the cost down quite a bit to $12.91.

We make that change, and then that's going to affect how much energy we produce with this amount of carbon emissions. And then we'll look at that a little bit later. But as a product, as a deliverable from this step, you're going to want to take a little screenshot of this pie diagram after you've run the model. You’ve got the new fossil fuel energy intensity and the unit cost here. You can go back to the start here by hitting this little undo button, return button. And there we go, back to the original.

PRESENTER: In this next step in this project, we're going to calculate the total energy demand. And we're going to do that simply by combining the population part of the model with the per capita energy curve here. So this shows the per capita energy in terms of exajoules of energy per billion people over the history of this model. Runs over about 200 years. And this is a graphical function of time that can be changed, and we'll change that here in just a second.

So if we run this model now, let's go back here to the beginning and run this model in time and see what happens. OK, here's our carbon emissions curve here, here's our global temperatures, so we are getting close to keeping it below three. Now if we go backwards here, here's our graph showing the global energy demand. Also the reference global energy demand. They're one in the same here because I haven't made a change to this curve here.

Also shown on here is zero right now is the energy conserved. So if I go ahead and change this curve here and lower the energy demand, that represents conservation of energy. So let's go ahead and do that. Make a little bit of a change here. Let's say we lower the energy demands through time like this. And on this graph, this line over here at the edge represents the year 2200. This line over here represents the year 2010. Every little increment here represents an additional 48 years, I think. OK, so we can adjust this history.

So I've have made some big steps energy conservation. Let's see what happens and we'll run the model. And sure enough the global energy demand is less than this reference value here. And the difference represents energy conserved. Now this energy conserved isn't free. It comes with a cost. And so later in this model you'll see the costs that are attributed to this conservation of energy.

And you can look at that if you just go back here to page five and you can see this pink line here, conservation costs. It's very, very low here. It looks like a flat line not changing. It's actually changing a little bit, but it still just stays a very, very low. So that's a very modest cost.

The other thing you can do, of course, in adjusting this model is to lower the population limit. So let's lower the population limit from something like 12 to something down near 9. We run the model and you see that everything gets shifted downwards. The reference curve gets shifted downwards, the actual global energy demand gets shifted down, and the energy conserved shifts down as well. So these two controls, population limit and per capita energy, are how you determine what the global energy demand is.

PRESENTER: For Step 4 in the Capstone Project, we're going to focus on the renewable energy sector up here. So, we're going to make some changes here. Or not, you can do it either way. But this is where you determine which of the different renewables, how much the total renewable energy portfolio they make up. So, this is what we currently have, so 45% of our renewable energy is hydro, right now, 28 nuclear, wind is 14, geothermal 7, solar 6. So, the idea is to change these and that mix along with the cost of these different energy sources, which you can see here. That determines the initial renewable energy unit cost. So, it's 12.63 billion dollars per exajoule of energy right now.

So, there are some limits here to these renewable fractions. You can find out about these. F hydro shouldn't exceed 46%. That's because there just aren't that many more big, highly productive dams that we can build. We've already dammed up the rivers in the best places, in general. So, it can grow a little bit, but not much. The geothermal shouldn't exceed 10%. It's geographically so limited that it's not going to be a huge player in the future. But solar, wind, and nuclear could each theoretically supply a 100%. But then, you know, whether or not you want to do that sort of depends on the costs.

So, look at the costs. Do you... nuclear is pretty expensive, 31 billion dollars per exajoule. Do you really want to have that much nuclear energy in your portfolio? Well, there might be some reasons have some, but it is expensive. So, how to make those changes? You just move these little white circles around. So, I'm going to reduce my nuclear here, just to show you this, I'm going to reduce that to maybe 6%. And geothermal, I can't have it be more than ten. But I kind of like geothermal, it is pretty inexpensive, so I'm going to keep that at ten. That's a good sort of constant steady supply. I'm going to keep hydro pretty much where it is. And then I'm going to split the remainder in terms of solar and wind. And I get those kind of close to each other. They're roughly about there. And the reason for doing that is that they complement each other, in general, so that during times of the day when you generate a lot of wind power, you don't generate a lot of solar power, and vice versa. So, it makes sense to have those be kind of balanced.

Now you notice I've made those changes. Here's my new renewable portfolio. This initial cost doesn't change until I hit the Run button and we see what happens. So, I've dropped that way down now. So that's 7.17. And so, then when you run the model and you look at things like the energy costs now, those energy costs are going to reflect this initial renewable energy here. If we're going to go way back here, if I go backwards and look at 15, This shows the energy costs changing over time. Fossil fuel energy up here and this is the renewable energy cost. So, it starts off at seven, but it drops to five billion per exajoule over time, just because the model assumes that the cost of wind and solar energy will continue to decrease following an exponential function. So that this is just matching what's happened in recent history in terms of price declines there. So, that's why that price continues to drop in the early stages of this scenario.

So that's, that's what it is. That's sort of the rundown on Step 4.

PRESENTER: Step 5 of the Capstone Project, we're going to focus on the total costs of your plan so far. Remember, your plan at this point will have consisted of a modified carbon emissions curve here, a modified per capita energy curve here, possibly a change in the population limit here, a change in the fossil fuel fractions, and a change in the renewable energy fractions.

And so, all of that leads to total costs here in yellow, this is page five of the graph pad, which is really just the sum of all these other curves. Four is the climate damage costs, which are quite high in this scenario, reaching a value of something like almost \$50 trillion by the end of the time, which is significant. If you look at on page nine, the GDP at the end is about \$600 trillion. So, it's you know, a little bit less than 10% of the GDP. It's pretty sizable chunk going to climate damage costs.

So, you take that value and you add to it, the renewable energy cost here - curve two, the carbon energy cost - curve one, and the conservation cost - curve three, which is zero, in this case. Zero because I haven't right now modified the per capita energy demands at all. So, we're not doing anything in terms of conservation. You're going to take a screenshot of this and include this in your, your poster, your presentation of your project and just comment about the relative magnitudes of these different costs, and then we'll consider some of these costs in a different way when we talk about Step 6 as the next thing.

PRESENTER: Now Step 6 of the project is pretty simple. We just turn to page 13 of the graph pad, and we look at the sum of the energy conservation and climate costs per person.

And so, this is going to be in thousands of dollars per person that's added up over time. So, this is a cumulative amount over this 200 year period, roughly. And you can see in our case here we’ve gotten that up to $600,000 dollars per person. And so, you know, you divide that by roughly 200 years and that averages out to like three thousand dollars per person, per year, in all of these costs, so, energy conservation and climate related costs.

So, that's each person's share. And this is the thing that we're trying to minimize, because if we can keep this as low as possible then that leaves more money for the rest of the economy, or the things the economy would do like, you know, health care, education, research, all these things that would contribute to a higher quality of life. So, this is, our goal is to minimize this. And so, you know you're going to include a screenshot of this page in in your project report, your poster, and talk about it a little bit.

But let me just show you what you're going to do. So, you get to this point Step 6, now what you want to do is to make some changes and then compare this first initial curve with something else. So, I'll change the carbon emissions to do something like this, drop off towards zero here shortly. So, if we run it with that and look at this same graph we see, okay we lower it significantly in that case. So, now we're down to 266, so that's better. And then you might, you know you could change the renewable energy portfolio again. You could change the fossil fuel allocations. You could make all these kinds of changes. You could reduce the per capita energy demand, keep that more or less flat, something like that and run it again and you see you get even better.

So, the idea is to is to kind of cycle through effectively Steps 1 through 5 and look at the result here. And so, once you've done this and you get to what is the lowest cost then you're going to make a screenshot of this. You're going to talk about the kinds of assumptions or changes to the model that you implemented to give you the lowest per capita cost at the end of it.