Disaster
A disaster is a serious problem occurring over a period of time that causes widespread human, material, economic or environmental loss which exceeds the ability of the affected community or society to cope using its own resources. Disasters are routinely divided into either "natural disasters" caused by natural hazards or "human-instigated disasters" caused from anthropogenic hazards. However, in modern times, the divide between natural, human-made and human-accelerated disasters is difficult to draw.Examples of natural hazards include avalanches, flooding, cold waves and heat waves, droughts, earthquakes, cyclones, landslides, lightning, tsunamis, volcanic activity, wildfires, and winter precipitation. Examples of anthropogenic hazards include criminality, civil disorder, terrorism, war, industrial hazards, engineering hazards, power outages, fire, hazards caused by transportation, and environmental hazards.
Developing countries suffer the greatest costs when a disaster hits – more than 95% of all deaths caused by hazards occur in developing countries, and losses due to natural hazards are 20 times greater (as a percentage of gross domestic product) in developing countries than in industrialized countries.

Etymology
The word disaster is derived from Middle French désastre and that from Old Italian disastro, which in turn comes from the Ancient Greek pejorative prefix δυσ- (dus-) "bad" and ἀστήρ (aster), "star". The root of the word disaster ("bad star" in Greek) comes from an astrological sense of a calamity blamed on the position of planets.

Classification
Disasters are routinely divided into natural or human-made. However, in modern times, the divide between natural, man-made and man-accelerated disasters is quite difficult to draw.Complex disasters, where there is no single root cause, are more common in developing countries. A specific disaster may spawn a secondary disaster that increases the impact. A classic example is an earthquake that causes a tsunami, resulting in coastal flooding, resulting in damage to a nuclear power plant (such as the Fukushima nuclear disaster). Some manufactured disasters have been wrongly ascribed to nature, such as smog and acid rain.Some researchers also differentiate between recurring events, such as seasonal flooding, and those considered unpredictable.

With links to natural hazards
Disasters that have links to natural hazards are commonly called natural disasters although this term has been called a misnomer for a long time.

Without links to natural hazards
Human-instigated disasters are the consequence of technological or human hazards. Examples include war, social unrest, stampedes, fires, transport accidents, industrial accidents, conflicts, oil spills, terrorist attacks, and nuclear explosions/nuclear radiation.Other types of induced disasters include the more cosmic scenarios of catastrophic climate change, nuclear war, and bioterrorism.One opinion argues that all disasters can be seen as human-made, due to human failure to introduce appropriate emergency management measures.Famines may be caused locally by drought, flood, fire, or pestilence, but in modern times there is plenty of food globally, and sustained localized shortages are generally due to government mismanagement, violent conflict, or an economic system that does not distribute food where needed. Earthquakes are mainly hazardous because of human-created buildings and dams; avoiding earthquake-generated tsunamis and landslides is largely a matter of location.

See also
References
External links

International Federation of Red Cross and Red Crescent Societies – IFRC
ReliefWeb of the United Nations Office for the Coordination of Humanitarian Affairs –ReliefWeb
United Nations Office for Disaster Risk Reduction – UNDRR
EM-DAT International Disaster Database of the Centre for Research on the Epidemiology of Disasters
Global Disaster Alert and Coordination System – a joint initiative of the United Nations Office for the Coordination of Humanitarian Affairs (OCHA) and the European Commission
UN-SPIDER – UN-SPIDER, the United Nations Platform for Space-based Information for Disaster Management and Emergency Response], a project of the United Nations Office for Outer Space Affairs (UNOOSA)