 This is the model that we're going to be working with in this lab, and it's similar to one you've seen before that combines a global carbon cycle with a global climate model. It includes components that calculate our energy needs and our sources of energy, which then relate to the carbon emissions that affect the climate. It also monitors the economics of all these changes to our climate and energy. This one also includes some geoengineering options that I'll explain in a little bit. So over here, there are a lot of controls that are kind of color coded according to the different things that they represent. So green here represents conservation of energy, the purple or blue represents renewable energy. The red down here relates to one of the geoengineering schemes, which is the direct carbon removal from the atmosphere. And the orange down here deals with the other geoengineering scheme, which is the injection of sulphate air sauce into the stratosphere to block sunlight. So let me just show you a couple of things about this. So you open the model and you run it, and it calculates this all out over a couple of hundred years, and this shows the global temperature change that results. And here we haven't really done anything to increase conservation renewables, and the geoengineering switches are off. So this is kind of the do nothing scenario, and we have a very high temperature rise by the end of this time here, six and a half degrees. So now we could say of course, well, what if we conserve energy? So this number here is the percent of our energy that we reduce by conservation methods, and this is the growth rate of that. So this is five percent increase per year, which is pretty good. So if we run this and see what happens, and compare it with the do nothing scenario, and you see it lowers the temperature, but it's still unacceptably high. And so you could say, well, what if we increase our reliance on renewable energy? Let's bring this up to, say, 75%. And we run that, and we see that this does a little bit better. But still by the end of this, like we're up at 3.6 degrees global temperature rise, which is really quite alarming. And by the year 2000, we're 2100, rather, we're above that two degree limit that we sort of agree upon as the upper limit in the Paris Climate Accords. So now we've added here some geoengineering options, and these are kind of like, if we just can't manage our carbon emissions through conservation and switch to renewables, we might want to investigate some of these to help us prevent a climate disaster. And so I'm going to restore the renewables to where it was before. I'll just turn this on. So now this is going to activate the direct removal of carbon from the atmosphere, and then the burial and sequestration of that carbon underground. So here's the time at which it starts 2030. And here you pick a target atmospheric CO2 concentration. So here I've got 400, this is raised that to 450 here. And this is the rate of cost decline of that process, which is initially fairly expensive. And this represents how quickly our capability to do this grows. And this gives us the initial amount of carbon that we can withdraw from the atmosphere in one year at the very start. So this is pretty generous because we can't really come close to doing one gigaton at the present time. But things are changing rapidly in this field. So let's see what happens here. And we run this and we see here's our results. And this brings us down, keeps us below two degrees for a very long time. So that is a fairly effective means of keeping our climate under control. You switch on some of the other pages, you'll see that this is in blue, the CO2 concentration of the atmosphere rises. And then we start to get it in control. And then we've brought it under control here for it's close to 450. It's a little bit above until this point in time in which it drops down dramatically. It drops down dramatically there just because we run out of fossil fuels. And so we're no longer able to emit any to the atmosphere at this point in time. So 21, 97 or 98, something like that. So that's the direct removal of carbon. Another option is sulfate aerosol geoengineering. And we turn that on. And this is where we inject sulfate aerosols, these little tiny particles into the stratosphere. They block some sunlight. And so here's the starting time for this process. And here's the targeted temperature change that we're going to try to control to. So this will try to keep the temperature change to two degrees or less. And this is the cost decline rate. This is zero right now, kind of assuming that, you know, this is not such a technologically tricky process. And probably we're not going to see huge advances in the, in the sort of ability to do this per dollar. So I've got that at zero initially. Well, let's just run this and see what happens. You run the model and there you see this does a very good job of keeping it right at two degrees through this whole time. Well, all of these changes have economic consequences. And some of those you can see on some of the other graphs here. Let's see this one is here's the total cost per person per capita. That is in terms of thousands of dollars per year. And those last two that we ran, they both end up costing something like about $9,000 per person per year by the end of it. And that's to pay for all of our energy supply and all the climate damages that are associated with the temperature change. So this is just a brief introduction to the model. You can restore everything to the sort of an initial by clicking those two buttons. And so we're going to do a series of experiments with this model to, to make some, some sort of assessments about what is the best thing from the standpoint of the climate and also the economy in terms of getting us to a future that, that includes a tolerable level of global warming.