Transformation of the Earth’s social and environmental systems is happening at an incredible pace. The global population has more than doubled over the last five decades, while food and water consumption has tripled and fossil-fuel use quadrupled. Attendant benefits such as longer lifespans and economic growth are increasingly joined by corresponding drawbacks, including mounting socioeconomic inequality, environmental degradation, and climate change. Over the past half-century, interregional differences in population growth rates, unprecedented urbanization, and international migration have led to profound shifts in the spatial distribution of the global population. Economic changes have been dramatic as well. The global per-capita gross domestic product doubled while economic disparities grew in many regions (Rosa et al. 2010).