Today our planet is home to 6.8 billion people. By the year 2050, the global population will have grown to 9 billion. Yet the problems that will come with this massive expansion are not universal. Many developing nations will experience high demographic growth, while industrialized countries will have to deal with aging and eventually shrinking populations, as well as with more immigration. "Overcrowded World: Global Population and International Migration" offers a perspective on the causes and effects of rapid population change, and asks two vital questions: how can Earth sustain this growth and what can we do to improve the living conditions of present and future generations.