This document provides an overview of natural hazards for a class on the subject. It discusses how the Earth is a dynamic planet that has changed over time. It also describes the Earth's atmosphere, biosphere, lithosphere, and hydrosphere as open subsystems, while the Earth itself can be considered a closed system. The document defines natural hazards, disasters, and catastrophes and notes how human activities can influence earth's processes and increase risks like landslides and flooding. The remainder provides a quiz on different natural hazards like earthquakes, volcanoes, landslides, and cyclones.