This document provides an introduction to environmental science through defining key terms and concepts. It discusses how environmental science is an interdisciplinary field that studies the interactions between humans and the natural world. It also summarizes the history of environmentalism, highlighting events like the agricultural depletion in Mesopotamia, the Progressive Era in the US, and Rachel Carson's book Silent Spring which brought attention to issues like pollution and pesticide use. The document outlines important concepts in environmental science including sustainability and the tragedy of the commons, and covers topics like renewable/nonrenewable resources and modern environmental movements.