This book's seventeen chapters offer readers an overview of humanity's demographic past, present, and near term population futures, with special attention paid to the challenges and implications that our current trajectories pose. Excerpt: "...the size and speed of growth of the human population today have no precedents in all the Earth's history before the last half of the twentieth century..." -- "...today's rapid relative and absolute increase in population stretches the productive, absorptive, and recuperative capacities of the Earth...."