For the fifth edition, all chapters have been revised and updated, and new pieces of line art, new photos, and new tables have been added. Changes include major reorganizations and expansions. Chapter 1 has more physical and economic data on disasters and hazards, and now covers human population, the condensed remains of the former Chapter 16. Chapter 2 examines energy flows in Earth history and natural disasters. Chapters 6 and 7 on vocanism have been significantly revised while retaining the continuous sequence based on plate tectonics and magma characteristics with eruptions explained using the 3 Vs-Viscosity, volatiles, and volume. Chapters 10 and 11 have been radically reorganized. They begin with expanded principles to increase the basis for understanding climate change and severe weather. Chapter 14 on fire has again added new figures and new tables on wildland fire data and how fires work. Chapter 15 on mass extinction has added new sections on fossils plus new photos.