Ecologists are now challenged to study global ecology. The apparent role played by humans in changing the global environment makes it imperative that we understand the workings of the earth as a global system. However, this study requires approaches that are significantly different from those that can be applied to traditional areas of ecological study. Historically, much of ecology focused on small areas and short-term studies. What are some of the main differences between global ecology and, for instance, the study of interspecific competition (see chapter 13) or forest succession (see chapter 20)? How will these differences affect the design of studies at the global scale?