A description of the response of the climate system to emission or concentration scenarios of greenhouse gases and aerosols, or radiative forcing scenarios, often based upon simulations by climate models. Climate projections are subject to uncertainty, because they are typically based on assumptions concerning future socio-economic and technological developments that may or may not be realized. 

Source: PAGASA (2011). Climate Change in the Philippines. Department of Science and Technology. http://www.pagasa.dost.gov.ph

Biological hazards are of organic origin or conveyed by biological vectors, including pathogenic microorganisms, toxins and bioactive substances. Examples are bacteria, viruses or parasites, as well as venomous wildlife and insects, poisonous plants and mosquitoes carrying disease-causing agents. 

Source: Definition: Hazard | UNDRR 

Biological hazards, which cover a range of hazards of organic origin, can cause significant loss of life, affecting people and animals at the population level, as well as plants, crops, livestock, and endangered fauna and flora, and can lead to severe economic and environmental losses (Wannous et al., 2017). They include pathogenic microorganisms, and toxins and bioactive substances that occur naturally or are deliberately or unintentionally released. Bacteria, viruses, parasites, venomous animals and mosquitoes carrying disease-causing agents are also examples of biological hazards. 

Source: Hazard Definition & Classification Review: Technical Report (2020) published by the United Nations Office for Disaster Risk Reduction (UNDRR)

Natural hazards are predominantly associated with natural processes and phenomena. 

Source: Definition: Hazard | UNDRR 

A description of the response of the climate system to emission or concentration scenarios of greenhouse gases and aerosols, or radiative forcing scenarios, often based upon simulations by climate models. Climate projections are subject to uncertainty, because they are typically based on assumptions concerning future socio-economic and technological developments that may or may not be realized. 

Source: PAGASA (2011). Climate Change in the Philippines. Department of Science and Technology. http://www.pagasa.dost.gov.ph

Hydrometeorological hazards are of atmospheric, hydrological or oceanographic origin. Examples are tropical cyclones (also known as typhoons and hurricanes); floods, including flash floods; drought; heatwaves and cold spells; and coastal storm surges. Hydrometeorological conditions may also be a factor in other hazards such as landslides, wildland fires, locust plagues, epidemics and in the transport and dispersal of toxic substances and volcanic eruption material. 

Source: Definition: Hazard | UNDRR 

Meteorological and hydrological hazards are those resulting from the state and behaviour of the Earth’s atmosphere, its interaction with the land and oceans, the weather and climate it produces, and the resulting distribution of water resources. According to EM DAT, from 1979 to 2019, 50% of all recorded disasters (including technological and ‘complex’ disasters), 56% of deaths and 75% of economic losses are attributed to weather, climate and water-related hazards. Some of the most devastating hazards include tropical cyclones, drought, riverine floods, and heatwaves. These hazards are observed, monitored, and forecasted by the national meteorological and hydrological services of each country. 

Source: Hazard Definition & Classification Review: Technical Report (2020) published by the United Nations Office for Disaster Risk Reduction (UNDRR)

Geological or geophysical hazards originate from internal earth processes. Examples are earthquakes, volcanic activity and emissions, and related geophysical processes such as mass movements, landslides, rockslides, surface collapses and debris or mud flows. Hydrometeorological factors are important contributors to some of these processes. Tsunamis are difficult to categorize: although they are triggered by undersea earthquakes and other geological events, they essentially become an oceanic process that is manifested as a coastal water-related hazard. 

Source: Definition: Hazard | UNDRR 

Geohazards are hazards with a geological origin. They have been divided into three hazard clusters, two of which – seismogenic and volcanogenic – are the result of Earth’s internal geophysical processes, and a third – shallow geohazards – are the result of surface or near-surface processes, generally resulting in erosion or some type of mass movement. Seismogenic hazards, commonly referred to as earthquakes, give rise to specific hazards such as ground shaking, subsidence or ground rupture, but can also trigger hazards such as tsunami or rockfall. Volcanogenic hazards give rise to a wide range of hazards from lava flow and rockfall to ashfall and ground gases. Some geohazards may be partially induced or exacerbated by human activity, such as earthquakes or sinkholes from mining activity, or coastal erosion from deforestation. 

Source: Hazard Definition & Classification Review: Technical Report (2020) published by the United Nations Office for Disaster Risk Reduction (UNDRR)

Societal hazards are brought about entirely or predominantly by human activities and choices, and have the potential to endanger exposed populations and environments. They are derived from socio political, economic activity, cultural activity and human mobility and the use of technology, but also of societal behaviour – either intentional or unintentional. Societal hazards also have the potential to result in disasters and cause significant numbers of deaths, illness, injury, disability and other health effects, disruption to societal systems and services, and social, economic and environmental impacts. 

Source: Hazard Definition & Classification Review: Technical Report (2020) published by the United Nations Office for Disaster Risk Reduction (UNDRR)

A characteristic of technological systems is their complexity, with many dependent subsystems. Thus, failure of one element within this system has impacts that spread throughout the chain. However, impacts can also occur outside the system, with a wide spectrum of impacts ranging from national interests | 29 UNDRR / ISC SENDAI HAZARD DEFINITION AND CLASSIFICATION REVIEW such as state security, to economics, health, and basic human needs. Technological hazards arise from the possibility of failure of an existing technology as well as from emerging technologies. 

Source: Hazard Definition & Classification Review: Technical Report (2020) published by the United Nations Office for Disaster Risk Reduction (UNDRR)

The Black Swan Theory refers to those events which are difficult to predict in the normal course of business. They are random, unexpected, but high-impact events. These events are considered outliers, because there is no past data which can point towards its occurrence in the foreseeable future. 

Source: What is Black Swan Theory? Definition of Black Swan Theory, Black Swan Theory Meaning - The Economic Times