 Hello, this is Processor Steven Neshba, and I want to help you out with the setting up and running of our simple Rated to Balance model. So the first thing you'll want to do after you go to the link is make your own copy of this. So that's what I'm going to do is make a copy. And if you want to share it with somebody who can, but for right now, I'm just going to make a copy. The next thing that I'll want you to do is to get the add-on called the Solver add-on. So you go here. Now, I've actually already done that, but if you haven't added it already, then you do the get add-ons and you're going to enter Solver here and choose it, and that's the one that you want on the left. So with those preliminaries, let me just kind of orient you here a little bit. The variables to adjust that we might want to adjust a fair amount are in green here. One of them is the anthropogenic back radiation forcing. That's the energy that's coming in from the atmosphere that's due to greenhouse gases that people have put into the air, which here in this pre-industrial column is set to zero because hadn't started it yet. There's the albedo, 30%. This number we'll maybe look at later. Here's some other numbers. This is the solar constant. That's the intensity of the sun. We're going to probably leave that alone for now. These are numbers that are calculated from the model. I just want to draw attention. This zero here is basically the same number here, which is that there's been no energy coming in from additional anthropogenic forcing. And here's a number that's of interest that it says this is the total energy coming in from the sun and also through back radiation from the atmosphere. This is the energy out. This is the glowing in the long wave. And you can see that those two numbers are the same, which means that there's the radiative difference is zero. That number minus that number. And the reason for that is that I've already tuned up the temperature, the earth, to be just what it should be in order for that to be so. But let's suppose I guessed wrong. Let's suppose I thought in pre-industrial times the temperature was only 10 degrees Celsius. Well, you can see what's happened here is that the radiative difference there's more energy coming in than out because that's a positive number. And now if there's more energy coming in than out, it must be that the earth's surface has to be warming up so I could put in another number there. That's a little bit higher. Oh, we're still warming up and until I get to that point and we could even make it negative, which would sort of indicate that the earth better cool down. But I'm going to leave that at 14. Now, so let's suppose we now are going to go to the present time. We, the driving force is two and a half watts per meter squared. Everything else is the same. And I can see that the radiative difference, oh well, I haven't put in a temperature here. So once again, I don't know what the temperature is going to be. I'm just going to put in a placeholder of 10 and I can see that that the radiative difference there's more coming in than going out. So obviously the temperature has to be higher. Now I could do and you could do this guess and check method. I think it's probably a good guess that it's bigger than 14, but I want to show you one more tool which is to use this solver. So I'm going to start the solver and here's how you use it. The objective is that this radiative balance be zero. So I'm going to say I want cell D 19 to be zero and that means I click on this a value of zero here. And how is it going to make it be zero? Well, I'm going to have it adjust the temperature, which is this D 22. So I think that's all good. I'm just going to hit the solve button and see what it comes up with. So Google Sheets is looking for the right temperature. Now it says it found a solution and look at that. It decided that the temperature at which radiative balance occurs is 15 degrees Celsius under conditions of an anthropogenic back radiation forcing of two and a half watts per meter squared.