In the span of a century, the world population quadrupled, rising from 1.6 billion in 1900 to 6 billion in 2000. This unprecedented level of growth has continued into the twenty-first century, seeing an increase of 2 billion in the first twenty years, and the UN predicts the population will grow to 11 billion by the end of the century. In the August issue of the Global Health Newsletter, the team examines how the ever-increasing population impacts the past, the present, and the future.