Basic Grouping of Disasters According to thier Origin

 A Holistic Classification

A Holistic Classification of Natural Disasters
Disasters Involving the Lithosphere 
Earthquakes
Volcanoes
Landslides

Disasters Involving the Hydrosphere
Tsunamis
Flooding

Disasters Involving the Atmosphere
Cyclones 
Hurricanes
Typhoons
Tornadoes
Thunderstorms
Lightning
 

Disasters Involving the Biosphere
Desertification
Extinction of Biota
 

Man-Induced Disasters
Climatic Change
Greenhouse Effect
 

Extraterrestrial Disasters
Asteroid Impacts