In the chapters in this section, we construct as best as we can an image of the present, and from that we extrapolate some of the broad brush images of the future. As will be seen, that image, even without global warming, is strikingly different from the world we live in today. Our research strongly suggests that current migration and refugee population flows are likely to remain at their already high volume, as more andmore people seek lives in urban settings. By the end of the century, most of the world’s population will live in megacities, cities with populations in excess of 25 million. In turn, most of these new residents will lack basic services, including fresh water, sewer and septic systems, and municipally funded security.