This document discusses several key concepts related to the environment and human-environment interactions. It defines the environment as the complex of living and non-living components that surround humans. It also discusses coupled human and natural systems, where social and natural systems interact in dynamical two-way relationships. Environmental issues often stem from humans overusing finite resources, but management, protection and sustainable engineering can help reduce negative impacts. Beliefs, economic activity, and the political system all influence the environment at a global scale.