Earth processes like debris flows and earthquakes are important for shaping the Earth's surface and can also have destructive effects on human infrastructure and life. Attempts to understand these complex Earth processes usually follow application of deterministic Newtonian physics. However, such attempts often cannot explain the observed complexity, which can be important for understanding the associated hazards and emergent behavior. Here, we describe a statistical mechanics approach and show how its application to debris flows and earthquakes allows for improved understanding of the most destructive aspects of these energetic systems.