 Every day I ask whether or not we are managing the world's resources in a manner that maximizes global human potential. In an age of tremendous technical progress and opportunity, we're building towers that reach almost a kilometer up into the sky. And we're landing rockets, Iron Man style, on autonomous floating rafts out in the ocean. But at the same time, millions of children grow up around the world with their bellies distended, because they're full of worms, because they don't have access to clean sanitation. And billions of individuals around the planet are working furiously to improve their economic opportunities for themselves and for their families. All of this activity puts tremendous strain on the world's resources. For example, we can see the clearing of the world's great forests from space. And in fact, the fingerprint of humanity is so profound that if I were an alien astronomer at the edge of the solar system looking at our pale blue dot and doing spectroscopy on our atmosphere, I would see the rise of humanity in my data. We stand at a moment in time where we have to make intelligent management decisions about what we're going to do with our planet and its climate that we've been handed. We have to decide whether or not we're going to invest resources today to reduce carbon emissions and mitigate climate change, or if we're going to spend those resources on something else and travel down a trajectory that's what we call a business as usual scenario. Now any intelligent manager will tell you that in order to make that decision wisely, they need to understand the value of those two different options. That's where I come in. My job is to help decision makers understand the economic consequences of these two different paths down the road. Now throughout history decision makers have exploited important technological innovations in the technology of governance, whether it's the idea that we should write down laws or the notion that individuals might be treated equally. We're in the midst of an important revolution in these technologies today as data and computing are allowing us to see what lies ahead in a manner and a clarity that we could never see before and make more informed choices. For example, when you look at the data and you look anywhere in the world at the economic building blocks that make up our global economy, whether it's a field of crops on a farm or it's a factory full of workers, we see that as temperatures rise populations handle these things pretty well up until a point. And when they hit a critical temperature, then these systems begin to break down and the productivity of these basic building blocks decline dramatically. What this means when we add it up and we think about how the larger economy that's made up of all these building blocks, when we think about how that economy responds to temperature, we see the same phenomenon. As the fundamental building blocks slow down, so does the larger economy. So as the temperature rises, if you start out cold and you're on the left side of these grass, whether you're around the world or in the United States, which is shown on the right, we see that productivity increases mildly up until you hit sort of the optimum temperature. But then if you keep increasing the temperature, productivities begin to decline. And we see that incomes fall as economies slide down the right-hand side of these hills. When we take these data and think about simulations in the future, looking at what will happen under global climate change, we see that large swaths of the planet will suffer in substantial ways economically. In particular, those regions of the world that have modest or warm temperatures today. We see that this adds up to a decline in global income of roughly 20% by the end of the century, shown on the left here. But importantly, you'll also notice that these forecasts are highly uncertain. If we change the climate, it makes it harder to predict the future. Now importantly, the places that are going to experience climate change most intensely in an economic sense are the hot places around the world, and those places also tend to be the poorest ones already. What this means is that the vast brunt of the cost, the economic burden of climate change will be borne by the poorest 60% of people around the world. This will lead to a global widening of inequality. Now you can take these results and use them to paint a more vivid picture of what the world will look like in the future and the choices that lie ahead. Here, what I've done is I've shown the colors on the globe to reflect the temperature in two possible futures. On the left is a world in which we have unmitigated climate change, and on the right is a world in which we invest heavily in transforming our energy system. Overlaid on these colors are lights reflecting human economic activity, and what I've done is I've intensified them or dimmed them down to show you how economic activity might evolve in a future simulation. Now you can look on the graph on the left and you can say the future looks bleak, and I'm going to be scared and a bit pessimistic about what lies ahead, but I'll tell you that's exactly the wrong reaction. What you should think instead is that things are looking up and that you should be optimistic because for millennia, decision makers have made choices about the future based on the location of the stars or a fortune teller rolling the dice. And for the first time in human history, we're able to exploit data, analytics, and computing to see forward in what lies ahead with clear eyes and to make informed decisions about the world we want to live in and leave to our children. Thank you very much.