Global threats—including climate change, nuclear proliferation, and pandemics—have people worried about the future of humanity. Siegel instead argues that there is good reason to be optimistic. At the core of the author’s thesis is the idea that the population explosion is “just about over” and that this is welcome news. “It will almost certainly end in this century,” he writes. As countries experience increased affluence and lower death rates, couples tend to have fewer children. Aided by new technologies, which enhance productivity and reduce the need to own so many things, “we are on the verge of the greatest democratization of wealth and well-being that the world has ever known,” and we will be richer “not just in money and goods, but in food, health, longevity, education, culture, safety, and just about everything else that people need and crave.” Moreover, writes Siegel, this democratized economic wealth will lead to a greener planet through protective policies and eco-technologies. The author backs up his sanguine outlook by citing dozens of economists and researchers, both historical and modern. This glut of data, often presented visually in charts and graphs, is both enlightening and cumbersome. The narrative is a remarkable resource but not a casual read. Still, Siegel does a good job of moving through dense analysis using prose that anyone can understand. He also recognizes that reaching global affluence, peace, and health has significant challenges, though his certainty that they can be overcome might seem overly optimistic in light of many grim current events. Democratizing education and technology and solving the problem of resource allocation for a population living longer are crucial. Siegel’s most salient argument is perhaps our most important goal, and it’s not simple: Everyone, in particular younger generations, must believe it can be done and that they possess the tools and minds to make a difference. A welcome antidote to apocalyptic thinking. (b/w photos, illustrations, charts, graphs)