Adisaster is a serious problem that happens over a period of time and causes harm to people, things, economies, or the environment that the affected community or society cannot handle it on its own.[1][2] In theory, natural disasters are those caused by natural hazards, whereas human-made disasters are those caused by human hazards. However, in modern times, the divide between natural, human-made or human-accelerated disasters is more and more difficult to draw.[3][4][5] In fact, all disasters can be seen as human-made, due to human failure to introduce appropriate emergency management measures.[6]
Disasters caused by natural hazards are things like avalanches, floods, earthquakes, and wildfires.[7] Further examples are cold waves and heat waves, droughts, cyclones, landslides, lightning, tsunamis, volcanic activity.[7] Disasters can also be caused by anthropogenic hazards such as criminality, civil disorder, terrorism, war, and power outages.
When disasters happen, developing countries often suffer the most. Over 95% of deaths from disasters occur in these countries, and they lose much more money compared to other countries. Losses due to natural hazards are 20 times greater (as a percentage of gross domestic product) in developing countries than in industrialized countries.[8][9]
A disaster is a result of a natural hazard impacting a vulnerable community. Poor planning or development or a lack of preparation are human failures which make communities vulnerable to climate hazards.[10] When the impact of these events becomes too extreme, they are often called disasters. Disasters are defined by their influence on people: if a hazard overwhelms or negatively affects a community, it is considered a disaster.[11]
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.[12][13][14]
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.[15]
Some researchers also differentiate between recurring events, such as seasonal flooding, and those considered unpredictable.[16]
Disasters that have links to natural hazards are commonly called natural disasters although this term has been called a misnomer for a long time.[17]
Example | Profile |
---|---|
Avalanche | The sudden, drastic flow of snow down a slope, occurring when either natural triggers, such as loading from new snow or rain, or artificial triggers, such as explosives or backcountry skiers. |
Blizzard | A severe snowstorm characterized by very strong winds and low temperatures |
Earthquake | The shaking of the Earth's crust, caused by underground volcanic forces of breaking and shifting rock beneath the Earth's surface |
Fire (wild) | Fires that originate in uninhabited areas and which pose the risk to spread to inhabited areas (see also Wildfire § Climate change effects) |
Flood | Flash flooding: Small creeks, gullies, dry streambeds, ravines, culverts or even low-lying areas flood quickly (see also Effects of climate change) |
Freezing rain | Rain occurring when outside surface temperature is below freezing |
Heat wave | A prolonged period of excessively hot weather relative to the usual weather pattern of an area and relative to normal temperatures for the season (see also Effects of climate change § Heat waves and temperature extremes). |
Landslide | Geological phenomenon which includes a range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows |
Lightning strike | An electrical discharge caused by lightning, typically during thunderstorms |
Limnic eruption | The sudden eruption of carbon dioxide from deep lake water |
Tropical cyclone | Rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls (see also Tropical cyclones and climate change) |
Tsunami | A series of waves hitting shores strongly, mainly caused by the displacement of a large volume of a body of water, typically an ocean or a large lake, usually caused by earthquakes, volcanic eruptions, underwater explosions, landslides, glacier calvings, meteorite impacts and other disturbances above or below water |
Volcanic eruption | The release of hot magma, volcanic ash and/or gases from a volcano |
Anatural disaster is the highly harmful impact on a societyorcommunity following a natural hazard event. Examples of natural hazard events include floods, droughts, earthquakes, tropical cyclones, volcanic activity, wildfires.[18] A natural disaster can cause loss of lifeordamage property, and typically leaves economic damage in its wake. The severity of the damage depends on the population's disaster preparedness and on the existing infrastructure.[19] Scholars have been saying that the term natural disaster is unsuitable and should be abandoned.[20] Instead, the simpler term disaster could be used, while also specifying the category (or type) of hazard.[21][22][23] A disaster is a result of a natural or human-made hazard impacting a vulnerable community. It is the combination of the hazard along with exposure of a vulnerable society that results in a disaster.
In modern times, the line between natural and human-made disasters is difficult to draw.[20][24][25] In fact, the term natural disaster was called a misnomer already in 1976.[23] Human choices around for example architecture,[26] fire risk,[27][28] and resource management[29] potentially play a role in causing or worsening natural disasters. Climate change also has an impact on the frequency of those disasters that are caused by extreme weather hazards (or "climate hazards"), such as floods, heatwaves, wildfires and tropical cyclones.[30]
Natural disasters can be worsened for example by inadequate building norms, marginalization of people and poor choices on land use planning.[20] Many developing countries lack effective disaster risk reduction systems.[31] This makes them more vulnerable to natural disasters than high income countries. An adverse event will only rise to the level of a disaster if it occurs in an area with a vulnerable population.[32][33]Human-instigated disasters are the consequence of technological or human hazards. Examples include war, social unrest, crowd crushes, fires, transport accidents, industrial accidents, conflicts, oil spills, terrorist attacks, and nuclear explosions/nuclear radiation.[34]
Other types of induced disasters include the more cosmic scenarios of catastrophic climate change, nuclear war, and bioterrorism.
All disasters can be regarded as human-made, due to human failure to introduce appropriate emergency management measures.[6]
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.[35]
Disaster | Profile |
Bioterrorism | The intentional release or dissemination of biological agents as a means of coercion |
Civil unrest | A disturbance caused by a group of people that may include sit-ins and other forms of obstructions, riots, sabotage and other forms of crime, and which is intended to be a demonstration to the public and the government, but can escalate into general chaos |
Fire (urban) | Even with strict building fire codes, people still perish in fires |
Hazardous material spills | The escape of solids, liquids, or gases that can harm people, other living organisms, property or the environment, from their intended controlled environment such as a container. |
Nuclear and radiation accidents | An event involving the significant release of radioactivity to the environment or a reactor core meltdown and which leads to major undesirable consequences to people, the environment, or the facility |
Power failure | Caused by summer or winter storms, lightning or construction equipment digging in the wrong location |
Major disaster, as it is usually assessed on quantitative criteria of death and damage, was defined by Sheehan and Hewitt (1969),[36] having to conform to the following criteria:[37]
This definition includes indirect losses of life caused after the initial onset of the disaster such as secondary effects of, e.g., cholera or dysentery. This definition is still commonly used but has the limitations of number of deaths, injuries, and damage (in $).[37] UNDRO (1984)[citation needed] defined a disaster in a more qualitative fashion as:
an event, concentrated in time and space, in which a community undergoes severe danger and incurs such losses to its members and physical appurtenances that the social structure is disrupted and the fulfilment of all or some of the essential functions of the society is prevented.[38]
As with other definitions of disaster, this definition not only encompasses the social aspect of disaster impact and stresses potentially caused but also focuses on losses, implying the need for emergency response as an aspect of the disaster.[37] It does not, however, set out quantitative thresholds or scales for damage, death, or injury, respectively.[citation needed]
As of 2019, countries with the highest vulnerability per capita release the lowest amount of emissions per capita, and yet still experience the most heightened droughts and extreme precipitation.[39] According to a UN report, 91% of deaths from hazards from 1970 to 2019 occurred in developing countries.[40] These countries already have higher vulnerability and lower resilience to these events, which exacerbates the effects of the hazards.
As of 2008, there were on average 400 disaster events per year, more than double the amount since the 1980s.[41]
Hazards such as droughts, floods, and cyclones are naturally occurring phenomena.[42] However, climate change has caused these hazards to become more unreliable, frequent and severe. They thus contribute to disaster risks. Countries contributing most to climate change are often at the lowest risk of feeling the consequences.[39]
Disaster response refers to the actions taken directly before, during or in the immediate aftermath of a disaster. The objective is to save lives, ensure health and safety and to meet the subsistence needs of the people affected.[46]: 16 This includes warning/evacuation, search and rescue, providing immediate assistance, assessing damage, continuing assistance and the immediate restoration or construction of infrastructure (i.e. provisional storm drainsordiversion dams). The aim of emergency response is to provide immediate assistance to maintain life, improve health and support the morale of the affected population. Such assistance may range from providing specific but limited aid, such as assisting refugees with transport, temporary shelter, and food to establishing semi-permanent settlements in camps and other locations. It also may involve initial repairs to damage or diversion to infrastructure.
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"[47] and ἀστήρ (aster), "star".[48] The root of the word disaster ("bad star" in Greek) comes from an astrological sense of a calamity blamed on the position of planets.[49]