Children and youth are greatly affected by disasters, and as climate instability leads to more weather-related disasters, the risks to the youngest members of societies will continue to increase. Children are more likely to live in risky places, such as floodplains, coastal areas, and earthquake zones, and more likely to be poor than other groups of people. While children and youth in industrialized countries are experiencing increased risks, the children and youth in developing countries are the most at risk to disasters. Children and youth are vulnerable before, during, and after a disaster. In a disaster, many children and youth experience simultaneous and ongoing disruptions in their families, schooling, housing, health and access to healthcare, friendships, and other key areas of their lives. Many are at risk to separation from guardians, long-term displacement, injury, illness, and even death. In disaster planning, there is often an assumption that parents will protect their children in a disaster event, and yet children are often separated from their parents when they are at school, childcare centers, home alone, with friends, and at work. Children do not have the resources or independence to prepare for disasters, so they are often reliant on adults to make evacuation decisions, secure shelter, and provide resources. Children also may hide or have trouble articulating their distress to adults after a disaster. In the disaster aftermath, it has been found that children and youth—no matter how personally resilient—cannot fully recover without the necessary resources and social support. Social location—such as social class, race, gender, neighborhood, resources, and networks—prior to a disaster often determines, at least in part, many of the children’s post-disaster outcomes. In other words, age intersects with many other factors. Girls, for example, are at risk to sexual violence and exploitation in some disaster aftermath situations. In addition, a child’s experience in a disaster could also be affected by language, type of housing, immigration status, legal status, and disability issues. Those living in poverty have more difficulties preparing for disasters, do not have the resources to evacuate, and live in lower quality housing that is less able to withstand a disaster. Thus, it is crucial to consider the child’s environment before and after the disaster, to realize that some children experience cumulative vulnerability, or an accumulation of risk factors, and that disasters may occur on top of other crises, such as drought, epidemics, political instability, violence, or a family crisis such as divorce or death. Even as children and youth are vulnerable, they also demonstrate important and often unnoticed capacities, skills, and strengths, as they assist themselves and others before and after disaster strikes. Frequently, children are portrayed as helpless, fragile, passive, and powerless. But children and youth are creative social beings and active agents, and they have played important roles in preparedness activities and recovery for their families and communities. Thus, both children’s vulnerabilities and capacities in disasters should be a research and policy priority.
Like any other species, Homo sapiens can potentially go extinct. This risk is an existential risk: a threat to the entire future of the species (and possible descendants). While anthropogenic risks may contribute the most to total extinction risk natural hazard events can plausibly cause extinction. Historically, end-of-the-world scenarios have been popular topics in most cultures. In the early modern period scientific discoveries of changes in the sky, meteors, past catastrophes, evolution and thermodynamics led to the understanding that Homo sapiens was a species among others and vulnerable to extinction. In the 20th century, anthropogenic risks from nuclear war and environmental degradation made extinction risks more salient and an issue of possible policy. Near the end of the century an interdisciplinary field of existential risk studies emerged. Human extinction requires a global hazard that either destroys the ecological niche of the species or harms enough individuals to reduce the population below a minimum viable size. Long-run fertility trends are highly uncertain and could potentially lead to overpopulation or demographic collapse, both contributors to extinction risk. Astronomical extinction risks include damage to the biosphere due to radiation from supernovas or gamma ray bursts, major asteroid or comet impacts, or hypothesized physical phenomena such as stable strange matter or vacuum decay. The most likely extinction pathway would be a disturbance reducing agricultural productivity due to ozone loss, low temperatures, or lack of sunlight over a long period. The return time of extinction-level impacts is reasonably well characterized and on the order of millions of years. Geophysical risks include supervolcanism and climate change that affects global food security. Multiyear periods of low or high temperature can impair agriculture enough to stress or threaten the species. Sufficiently radical environmental changes that lead to direct extinction are unlikely. Pandemics can cause species extinction, although historical human pandemics have merely killed a fraction of the species. Extinction risks are amplified by systemic effects, where multiple risk factors and events conspire to increase vulnerability and eventual damage. Human activity plays an important role in aggravating and mitigating these effects. Estimates from natural extinction rates in other species suggest an overall risk to the species from natural events smaller than 0.15% per century, likely orders of magnitude smaller. However, due to the current situation with an unusually numerous and widely dispersed population the actual probability is hard to estimate. The natural extinction risk is also likely dwarfed by the extinction risk from human activities. Many extinction hazards are at present impossible to prevent or even predict, requiring resilience strategies. Many risks have common pathways that are promising targets for mitigation. Endurance mechanisms against extinction may require creating refuges that can survive the disaster and rebuild. Because of the global public goods and transgenerational nature of extinction risks plus cognitive biases there is a large undersupply of mitigation effort despite strong arguments that it is morally imperative.
Abdelghani Meslem and Dominik H. Lang
In the fields of earthquake engineering and seismic risk reduction the term “physical vulnerability” defines the component that translates the relationship between seismic shaking intensity, dynamic structural uake damage and loss assessment discipline in the early 1980s, which aimed at predicting the consequences of earthquake shaking for an individual building or a portfolio of buildings. In general, physical vulnerability has become one of the main key components used as model input data by agencies when developinresponse (physical damage), and cost of repair for a particular class of buildings or infrastructure facilities. The concept of physical vulnerability started with the development of the earthqg prevention and mitigation actions, code provisions, and guidelines. The same may apply to insurance and reinsurance industry in developing catastrophe models (also known as CAT models). Since the late 1990s, a blossoming of methodologies and procedures can be observed, which range from empirical to basic and more advanced analytical, implemented for modelling and measuring physical vulnerability. These methods use approaches that differ in terms of level of complexity, calculation efforts (in evaluating the seismic demand-to-structural response and damage analysis) and modelling assumptions adopted in the development process. At this stage, one of the challenges that is often encountered is that some of these assumptions may highly affect the reliability and accuracy of the resulted physical vulnerability models in a negative way, hence introducing important uncertainties in estimating and predicting the inherent risk (i.e., estimated damage and losses). Other challenges that are commonly encountered when developing physical vulnerability models are the paucity of exposure information and the lack of knowledge due to either technical or nontechnical problems, such as inventory data that would allow for accurate building stock modeling, or economic data that would allow for a better conversion from damage to monetary losses. Hence, these physical vulnerability models will carry different types of intrinsic uncertainties of both aleatory and epistemic character. To come up with appropriate predictions on expected damage and losses of an individual asset (e.g., a building) or a class of assets (e.g., a building typology class, a group of buildings), reliable physical vulnerability models have to be generated considering all these peculiarities and the associated intrinsic uncertainties at each stage of the development process.
Vulnerability is complex because it involves many characteristics of people and groups that expose them to harm and limit their ability to anticipate, cope with, and recover from harm. The subject is also complex because workers in many disciplines such as public health, psychology, geography, and development studies (among others) have different ways of defining, measuring, and assessing vulnerability. Some of these practitioners focus on the short-term identification of vulnerability, so that maps and lists of people living “at risk” can be generated and used by authorities. Others are more concerned with reasons why some people are more vulnerable when facing a hazard or threat than others. Professionals working at the scale of localities are interested in methods that bring out residents’ own knowledge of hazards and help them to cooperate with each other to find ways of reducing risk. There are some interpretations of vulnerability that seek its root cause in the creation of risk by political and economic systems that make investment and locational decisions for the benefit of small elites without regard for how these decisions affect the majority. Finally, whatever success there may be in treating vulnerability in any of the ways just mentioned, it will always be a part of the human condition, and this fact in itself is puzzling.