Natural Disasters
A natural disaster is a major adverse event resulting from natural processes of the Earth that causes significant loss of life, property damage, or environmental disruption. For the full classification of disaster types by origin and the distinction between hazards and disasters, see [[overview/definition-and-classification]].
Natural disasters are classified by their originating physical processes into several major categories. Geological disasters arise from the Earth's internal dynamics, including earthquakes caused by tectonic plate movement along faults[^c1], volcanic eruptions driven by magma ascent, and tsunamis generated by underwater seismic or volcanic disturbances[^c2]. Meteorological and hydrological disasters stem from atmospheric and water-cycle extremes, such as tropical cyclones that form over warm ocean waters exceeding 27°C (80°F)[^c3], tornadoes produced by supercell thunderstorms[^c4], floods affecting nearly 2 billion people worldwide[^c5], and storm surges that represent the leading cause of hurricane fatalities[^c6]. Climatological disasters, including droughts and wildfires, emerge from longer-term climatic patterns, with drought causing an average of $11 billion in damages annually[^c7] and wildfires playing a complex ecological role in many ecosystems[^c8]. Biological and space-origin disasters, such as pandemics, locust swarms, and asteroid impacts, represent additional distinct categories.
The frequency and severity of many natural disasters are being amplified by climate change. Global warming added an additional six weeks of dangerously hot days globally in 2024, with Caribbean and Pacific island states experiencing approximately 150 more days of dangerous heat[^c9]. Heat-related mortality for people over 65 increased by approximately 85% between 2000–2004 and 2017–2021[^c10]. In 2024, global natural perils resulted in total direct economic costs of $417 billion[^c11], and insured losses from natural disasters are increasing by 5 to 7 percent annually after inflation. International frameworks such as the Sendai Framework for Disaster Risk Reduction 2015–2030 and the Early Warnings for All initiative aim to reduce these losses, with studies showing that 24 hours of advance warning can reduce damage by 30 percent[^c12].