 Before, the first thing to do is to just run the model. This is our control case. So this is where we do nothing. And now we're going to reduce all of our different fossil fuel uses. And so we need to turn on the coal switch, the oil switch, the gas switch. We're going to make the reduction times all be 20. So I could change that to 20. Here's the oil reduction time. Change that to 20. Gas reduction time, change that to 20. These changes are all going to start in the year 2020. Now we want the fraction of coal that we end up using after that 20 year period to drop down to 0.05. And if we look at coal now, we see we have 0.27. That's the fraction of coal we use today. So we want that to end up at 0.05. So we need to reduce it by 0.22. So I'm going to put in 0.22 there. Now for oil, I see that we're using 0.33. So we need to reduce that by 0.28. And after reducing that amount, then oil will be at 0.05. And for gas, we need to reduce that by 0.16. Now we've made all those changes. We're ready to go. Remember, I've reset the population limit to be 12. So that's our standard case. Now we run the model and we see what happens. And look, the emissions are way down here. And so you find the emissions level in 2100 here. Subtract that from what it is up there. And the difference is your answer. It's going to be 29.6, roughly minus 5.74. So you do that math, and that's the difference.