Is overpopulation real? Is Earth filling up with too many humans? How many people can Earth hold, anyway? As our species approaches 8 billion, human overpopulation is a major concern for many people. How can we reduce poverty and our impact on the environment? Do we need a forced one-child policy or something? Maybe not, because when we look at the science and history, populations seem to control themselves. This week we look at all these questions and more.