In 2011, the world population reached seven billion, adding to concerns about how to feed this vast number of people and how it will affect global warming, the energy supply, and health care. This volume is a comprehensive guide to overpopulation: how it happens in the United States and in other parts of the world, what it means, and what can be done to ease the issues that arise due to overpopulation. This is a modern issue, making it relevant to current events taught in a classroom.