Disaster and Climate Change


The author thanks Kingkarn Waiyanak for the literature search and retrieval and Glenn K. Shingledecker for his help in editing the manuscript.


Climate change, consequent to the phenomenon of global warming resulting from the anthropogenic emission of greenhouse gases, is expected to lead to increasing temperatures and changing rainfall patterns over the next century. Climate change can be both a complex and protracted hazard, potentially affecting both the environment and human population by changing the distribution of various risk factors. Climate change is a multifaceted (from drought to flood) and multidimensional (from local to global) hazard that has short-, medium-, and long-term effects and unknown outcomes.

Global climate change is increasing the risk of extreme weather and climate events, such as droughts, floods, heat waves, and stronger storms. In the 21st century, increases in frequency and severity of heat waves, cold waves, drought, and flooding are expected globally, even in temperate regions. Projections of global climate change for 2100 are striking: The Intergovernmental Panel on Climate Change (IPCC) predicts an average global temperature increase in the range of 1.0-6.4 °C, a rise in sea levels by as much as one meter, and an intensification of the hydrologic cycle in a warmer atmosphere, likely making droughts and floods more frequent and intense.

Climate change is intensifying the hazards that affect human livelihoods, settlements, and infrastructure. It is also weakening the resilience of community systems by increasing the uncertainty and frequency of disasters. Population movements in response to climate change may also result in new exposures to hazards. Furthermore, climate change can increase the vulnerability to unrelated, nonclimatic hazards, such as an urban earthquake hitting when the elderly population is already suffering from the sort of heat wave that occurred in Europe during 2003.

Historical perspective

Disasters triggered by natural hazards are killing more people and costing more money every year. A heat wave can have a large impact on human health. Health care personnel are increasingly confronted with severe heat-related illnesses (such as heat exhaustion and life-threatening heatstroke), which they are often neither familiar with nor trained to treat. The mortality rate from a heat wave is greater than from hurricanes, lightning, tornados, floods, and earthquakes combined and is an environmental hazard that can have serious public health consequences.

In the summer of 2003 a heat wave killed more than 14,800 people globally with heavy casualties and massive heat wave-related deaths recorded in Europe, the United States, and China. The risk of heat-related mortality increases 2.49% for every increase of 1 °F in heat wave intensity and 0.38% for every increase of 1 day in heat wave duration. Climate change may increase the frequency, duration, or intensity of heat waves. Heat waves are discussed in more detail in Chapter 99 .

Drought has an adverse effect on economies, food security, community nutritional status, and health-related issues. Malnutrition is often seen in chronic drought-affected areas. The cocoliztli outbreak of hemorrhagic fever occurred in Mexico during a severe and sustained megadrought. The simultaneous effect of the heat and the drought also raised the frequency of fires and caused energy blackouts. Chronic drought can lead to famine, which is discussed in more detail in Chapter 102 .

Projected changes in climate are expected to increase flood risk. During 2000 to 2010, many countries of the world experienced natural disasters resulting from floods. Flooding is the most common natural disaster that affects developed and developing countries. Standing water and sediments remaining in flooded areas are breeding grounds for various microorganisms, including fungi and bacteria, that can become airborne and be inhaled. These exposures may increase the incidence of lung disease, allergic respiratory disease, asthma, and mycotic infections in immunocompromised subjects. Bacterial growth in flooded homes can be a significant source of endotoxins, which can induce airway inflammation and dysfunction. Floods are discussed in more detail in Chapter 97 .

Tropical cyclones (typhoons and hurricanes) and tornados are devastating and recurring natural disasters that cause significant damage to life and property in many countries worldwide. As the ocean water cycle is projected to change under global warming, tropical ocean barrier layers may change accordingly. The relationship between temperature and the frequency of typhoon hazards is supported by the fact that typhoons form over tropical oceans where water temperatures reach or exceed 27 °C. Typhoon activities may also be related to ocean-atmosphere fluctuations, such as the El Niño activity and Southern Oscillation. It is expected that typhoon hazards will become ever more frequent in the next century as global temperatures continue to rise. Strong winds pile up the water along the shore and generate storm surges, causing coastal flooding, which results in damage and fatalities in the affected areas. The unprecedented disasters caused by Hurricanes Katrina and Rita in 2005 disrupted the public health and medical infrastructures in New Orleans and created many difficult environmental health challenges. While the infrastructure of an affected community usually remains at least partially intact, these storms can result in mass-casualty situations for emergency and local medical facilities. Tropical cyclones, hurricanes, and typhoons are discussed in more detail in Chapter 94 .

The intersection between climate change, disasters, health, and development is an area of concern for community development. Understanding how climate changes affect health through historical precedent is the key to preparing communities for disasters. Excess mortality rates during the devastating 2003 heat wave in Europe and during the recent 2006 heat waves in the United States and Europe have shown that extreme temperatures remain a major challenge to public health preparedness.

Current practice

Preparedness and Prevention

Most hazards that lead to disasters cannot be prevented, but their effects can be mitigated. Changes in the climate influence changes in the frequency and magnitude of those hazards. Vulnerability to these hazards is also increasing due to rising poverty, a growing global population, armed conflict, and other underlying development issues. Whereas climate change is contributing to raising disaster risk, measures to mitigate the risk need to focus on reducing vulnerability in the context of development efforts. Disaster preparedness must change from a conventional response and relief to a more comprehensive risk reduction concept ( Fig. 8-1 ). To be successful in disaster reduction planning and preparedness, it is important to have an in-depth understanding of the underlying vulnerabilities to natural hazards and the basic perceptions, goals, and behaviors of the local people. The local population’s relationship with the environment is essential. Planners, policymakers, and development practitioners should endeavor to understand local knowledge and practices. The underlying causes of vulnerability to disasters locally are often economic and societal, such as poverty, fragmentation of community cohesion, and lack of access to political representation. Climate-related vulnerability is derived from a set of social, economic, political, and physical factors. The risk to a population arises from the interaction of these hazards and vulnerabilities. It is important to set up a plan based on durable solutions for the protection of the population, particularly the more vulnerable, from future natural disasters. The “Hyogo Framework for Action 2005-2015,” which came out of the World Conference for Disaster Reduction in 2005 and was endorsed by the United Nations General Assembly, outlines steps required for disaster risk reduction to natural disasters and promotes a strategic and systematic approach to reducing vulnerabilities and risks to hazards. It identifies ways of building the resilience of nations and communities to disaster. The efforts to reduce disaster risk must be systematically integrated into policies, plans, and programs for sustainable development and poverty reduction, and be supported through regional and international cooperation.

Fig 8-1

Climate change, disaster risk management, and national development policy linkage.

Modified from Schipper L, Pelling M. Disaster risk, climate change and international development: scope for, and challenges to, integration. Disasters . 2006;30:19-38.

Steps taken by human society, either as individuals or governing authorities, toward risk reduction for natural hazards may be characterized as flexible or inflexible depending on the perception of the hazard, choices available, economic efficiency, and power structure of the government. The degree of destruction is a function of the human context as much as the hazard itself because hazards of similar severity can produce dramatically different outcomes in different social and economic contexts. All of this information is vital to strategic planning and decision making. Planning to reduce the impact of disasters requires many techniques to prepare for, to reduce potential losses from, and to respond and adapt to hazards. Unfortunately, poorly planned development interventions may become a source of hazards. Disaster planning is a necessary step and is needed to realize the goals of sustainable development. Because climate change is a source of multiple hazards that threaten long-term developmental actions by the international community, planning approaches that link development and disaster should extend to climate change. An appropriately trained, qualified, and agile health workforce is required to improve the response to disasters. Furthermore, crisis simulation exercises can be excellent opportunities to practice and modify risk reduction guidelines. Successful management of disasters will also maximize the resources available to adapt to future climate change.

Information technologies can facilitate coordination in all disasters, particularly those related to climate change, environment, and weather. The intrinsic chaos caused by a disaster challenges the coordination between organizations to prevent misunderstanding and to slow collective actions. New technologies (such as the geographic information system, command and control and decision support systems, varieties of social media, and sms messaging) are used extensively in a crisis response. E-mail can be used for vertical, horizontal, and interorganizational and intraorganizational coordination by a formal or emergent response network. This method is a potentially reliable and profitable tool to support coordination in a crisis response. An ad hoc crisis management system was used effectively in the SARS outbreak in Singapore in 2003, in response to the tsunami of 2004 in Sri Lanka, and in the San Diego fires in 2007. The role of informatics, mobile disaster applications, and social media in disasters is further discussed in Chapters 25 , 43 , and 44 .

Heat waves have had debilitating effects on human mortality. Global climate models predict an increase in the frequency and severity of heat waves. Annual mortality attributable to heat waves for Chicago (using several global climate models and climate change scenarios) found that mortality will increase in the future and that a mitigation of this projected increase may be expected through a lower pathway of future carbon dioxide emissions. Protective measures against heat are to withdraw from hot weather, implement widespread installation of air-conditioning in hospitals, nursing and retirement homes, and public buildings, and to facilitate their accessibility for vulnerable populations. Air-conditioning should be made affordable for low socioeconomic groups by reducing energy costs during extreme heat waves. Other steps include installing an early warning system, providing advance reports in the news media, broadcasting simple advice, and seeking out the most vulnerable and ensuring their well-being within the community. These measures have already been shown to reduce morbidity and mortality during heat waves. During the summer in Chicago, there are a graded series of warnings (via television, radio, and newspapers). Private and public resources (such as air-conditioned cooling centers) are mobilized, transportation is provided, the public and police are encouraged to check on their neighbors (especially the elderly and infirmed), public health officials and hospitals are alerted to look for early patterns of emergency department admissions and deaths, and a heat awareness week is set up to reduce the incidence of heat-related mortality. Toronto public health uses a protocol that calls for activation of a heat warning (alert) using a threshold of a 1-day forecast of the humidex (a Canadian summer temperature and humidity index) over 40 °C. A heat alert activates the city’s hot weather response plan that coordinates the efforts of the city and community agencies to provide services to socially isolated individuals (including homeless people), seniors, and medically at-risk people. This, combined with well-designed, planned community responses, can reduce the amount of heat-related morbidity and mortality.

Flood management includes different water resource activities. Sustainable flood management requires an integrated consideration of economic, ecological, and social consequences of disastrous floods. There are three main stages in flood management: (a) planning, (b) flood emergency management, and (c) postflood recovery. Different alternative measures (both structural and nonstructural) are analyzed and compared for possible implementation to minimize future flood damage during the flood planning stage. In the response stage of emergency management, regular evaluation of the current flood situation and daily operations is performed. Postflood recovery involves numerous decisions regarding return to normal life. The main issues during this stage include assessment and rehabilitation of flood damage and provision of flood assistance to flood victims. In all three stages, the decision-making process takes place in a multidisciplinary and multiparticipatory environment.

Several flood defense mechanisms can be used to protect a city and its population. The waterfront in New York City plays a crucial role as the first line in managing flood risk and protecting the city from future climate change and the rise in sea levels. This “greener waterfront” is also attractive for business and residents. Restrictions and enforcement of infrastructure construction (e.g., flood-proof telephones, electricity switchboards, and heating and gas installations above the base flood elevation level) can be implemented to reduce flood risk and damage. Building an infrastructure like a fail-proof, low-maintenance levee has proven to protect the Japanese cities of Tokyo and Osaka. This type of flood protection offers advantages beyond the structural and flood protection aspects. The stabilized and strengthened sides can be developed to extend the urban development area to the top of the levee and allow easier visual and physical access to the water.

Climate-adaptive programs should include the following: (a) modifying policies to anticipate the impacts of climate change, (b) improving resilience to climate change and the rise in sea levels, (c) changing future land use (e.g., flood zoning policies, flood insurance, and building codes) and hence the potential vulnerability of land use to flood risk, and (d) developing flood risk maps (e.g., delineating hazard areas, mapping floodways, and flood elevation and velocity). The major sources of uncertainty in the hydrologic impacts of climate change should use a multimodel approach, combining the output of multiple emission scenarios, global climate models, and conceptual rainfall runoff models within the framework of the generalized likelihood uncertainty estimation to quantify uncertainty in future impacts at the catchment scale.

An insurance program is important to achieve risk reduction by limiting the vulnerability of new construction to flood hazards. Insurance has been referred to as an effective tool for reducing, sharing, and spreading climate change-induced disaster risks in both developed and developing countries. Government funding in flood prevention also plays a crucial role in mitigating potential flood damage. Long-term planning and sustainability with its established relationships with multiple stakeholders are well positioned to coordinate, explore, and foster the implementation of a plan. Four key criteria regarding the long-term sustainability of effective insurance in natural disaster risk are contribution to risk reduction, commercial viability, affordability, and governance.

In 2008 the International Federation of Red Cross and Red Crescent Societies used a seasonal forecast to implement an early warning system in West Africa. This was one of the early action strategies for enhanced flood preparedness and response. This approach improved their capacity and response; potential benefits were realized from the use of medium-to-long–range forecasts in disaster management, especially in the context of extreme weather and climate-related events due to temperature variability and change. The full potential of these forecasts will require continued effort and collaboration among the disaster managers, climate service providers, and major humanitarian donors. Early warning, early action (EWEA) is one strategy that was developed to help disaster managers benefit from the various types of information, making full use of scientific information on all timescales. The EWEA concept aligns with increasing emphasis within the disaster risk management community on preparedness, awareness, and risk reduction. Disaster managers will need to invest more in preparedness, early warning, and vulnerability reduction rather than focusing primarily on response.

Cyclone preparedness in Bangladesh, exemplified by the existing comprehensive disaster management policies of the government and localized vulnerability factors in cyclone hazards, are also mandatory. An analysis of the relationship between cyclone hazards and human behavior in coastal areas (using local-level and personalized accounts) appears to be imperative for developing improved disaster reduction strategies. The locations and patterns of settlements are the most important factors when determining a coastal population’s vulnerability to a tropical cyclone, followed by inappropriate land management systems, the means of livelihood, and a lack of infrastructure.

Three underlying vulnerabilities to cyclone disasters are hazard risk perceptions, precyclone decisions about whether to go to shelters, and inadequate land management policies in the coastal areas of a country. Typhoon hazards can be prevented and mitigated by adopting a number of measures, including stricter observance of construction guidelines, new flood barrier proposals (as well as enhanced associated flood defense), and upgraded existing pumping systems along with better management of the collection of household litter and construction refuse. Insurance can also help the vulnerable population mitigate the effects from a typhoon.

Blizzards are predictable disasters with preventable health outcomes. Specific demographic, health, and cause-related information can assist health care providers and public health officials in providing more effective warnings to reduce blizzard-related morbidity and mortality in the general population.

The best way to reduce vulnerability is to improve the socioeconomic standing of the most vulnerable; for this to happen, these people must have an assured income based on assets that will enable them to acquire social and economic credit worthiness within the local economy. People with resources can protect themselves economically and physically from disasters; the speed of their recovery is related to the size of their asset base. The case can be made that poverty alleviation should be the central aim of all disaster reconstruction and development programs.

Response and Recovery

Capacity, including health care capacity, was one of the objective determinants identified as the most significant in influencing the adaptive capability of disaster response systems. There are several elements that can support the adaptive capacity of the health care sector, such as inclusive involvement in disaster coordination, policies in place for health workforce coordination, belief in their abilities, and strong donor support. Factors constraining adaptive capacity include weak coordination of international health personnel, lack of policies to address health worker welfare, limited human and material resources, shortages of personnel to deal with psychosocial needs, inadequate skills in field triage and counseling, and limited capacity for training.

The response to a heat wave involves various types of organizations. The response network is composed of groups with specific missions and objectives, which include civil protection and public security and order in routine situations by police organizations that are charged with the additional responsibility of providing emergency services (e.g., caring for injured people and organizing rescue operations). The group of health care organizations needs to be in charge of taking care of the injured and sick. Other outsider organizations need to have significant influence on the development of a crisis response. Unequal distribution of community-based resources has important implications for geographic differences in survival rates during a heat wave; this may be relevant for other disasters. The risk factors in heat wave mortality are being elderly, male, sick, grossly obese, disproportionately poor, residing in an economically and socially disadvantaged neighborhood, and living in a socially isolated population. A heat wave for consecutive days leads to widespread heat-related injuries and hospitalization and a rapidly increasing mortality rate. The pattern of a temperature greater than 37 °C being maintained for several consecutive days and an elevation of the minimum temperature above 25.5 °C does not allow recovery from a severe heat-stressed experience. The higher the temperature or the longer the heat wave, the more work is required for the cardiovascular system to maintain normal body temperature; therefore, a more intense or longer heat wave is likely to have greater health effects.

The greatest mortalities seen in heat emergencies resulted from sudden death and cardiovascular causes. Many of those who survived heatstroke were anticipated to sustain severe neurologic damage, which may culminate in death even up to 1 year or more after the illness. Extreme heat also poses a salient risk to the health and well-being of the mentally ill. Elevated and fluctuating temperature may exacerbate psychiatric conditions and increase the incidence of depression and suicide. Risk factors known to increase susceptibility to heat illness are social isolation of elderly people with comorbid conditions (such as psychiatric, pulmonary, or cardiovascular illnesses), the use of medications that interfere with thermoregulation, and the absence of air-conditioning. Local health care providers, such as emergency medical services and hospitals, need to prepare to handle the patient surge, diagnoses, and care.

Severe drought has an adverse impact on food reserves. There is a higher incidence of inadequate vitamin A status of rural preschool children, particularly those with illiterate mothers and belonging to an older age group. Communities need to provide medical care, including nutritional support and education.

Data from the National Oceanographic and Atmospheric Administration (NOAA) in the United States reported more death and destruction from flood than any other hydrometeorlogic phenomenon from 1990 to 2005. Flooding usually makes responses to a disaster more complex due to the damage of local infrastructure. The accessibility to the affected areas is quite difficult for all external organizations. Flash flooding is defined as flooding that occurs within 6 hours of the inciting event, such as heavy rainfall or levee or dam failure. The moving water is very powerful. The lateral force of one foot of water moving 10 miles per hour is about 500 pounds, and 2 feet of water at 10 miles per hour will float virtually every car.

Because flash flooding occurs so quickly, it can have lethal effects on anyone caught in its path. The vulnerable groups (e.g., disabled, elderly, and children) are the first priority in a flood response. Injuries are likely to occur during the aftermath and cleanup stage, but most of them are mild, predominantly consisting of cuts, lacerations, puncture wounds, and strains/sprains to the extremities. Most medical care for flood victims is routine, such as providing refilled medicines and treating exacerbations of preexisting diseases. However, in the later stage, infectious disease, arthropod bites, and violence can be overwhelming. The typical infectious diseases listed in association with excess flood exposure are leptospirosis, dengue fever, malaria, measles, typhoid, viral diarrheal illnesses, pink-eye disease, and hepatitis A virus infection. Melioidosis (discussed in Chapter 137 ) can be included in the differential diagnosis of patients with severe community-acquired pneumonia and skin and soft-tissue infections during and after flood exposure. , Unprecedented flooding and disasters provide ample ideal niches for the growth of fungi and bacteria that result in an increased risk of exposure to some biocontaminants derived from these microorganisms. The level of endotoxins was elevated in the dust collected from flood-affected homes 2 years after the floods. Leptospirosis is known to be an important cause of weather disaster-related infectious disease epidemics after seasonal rains and flooding in endemic wet zones. Field epidemiology is very important to identify the needs in every stage of the response and to provide information to the incident commander for decision making.

In tornado situations factors associated with seeking shelter were hearing warning sirens, having a basement in one’s home, having a plan of action, and having at least a high-school education. A tornado-warning system decreased tornado-related deaths, and it had to be coordinated with accessibility to a shelter. Storm shelters in tornado-prone areas should have quick accessibility by the residents. Seeking appropriate shelters after hearing tornado warnings is associated with reduced mortality and injury. It is recommended that people who live in tornado-prone areas without underground shelters should prepare a plan of action to immediately respond to tornado warnings in an effective manner. The engagement of tornado drills will allow the community to be familiar with safety procedures, sources of shelters in houses and outdoors, and weather updates. Public education about how to respond to tornado watches and warnings in areas with high tornado activity is mandatory.

Blizzard conditions were associated with increased visits for myocardial infarction and angina even in people without preexisting heart disease. Those myocardial infarction and angina visits were primarily related to shoveling and decreased visits to a physician for asthma. The decrease in physician visits for asthma most likely resulted from asthmatic people avoiding exposure to blizzard conditions. There is an association between heavy snowfall and ischemic heart disease morbidity and mortality. Other diseases are carbon monoxide poisoning (associated with blocked vehicle exhaust pipes), drug or medication overdose, alcohol abuse, and attempted suicide.

Disasters usually create a huge number of casualties, but the majority are minor casualties. Most of the deaths were attributed to heat, although those affected were essentially the elderly (70% and 120% excess deaths in the age groups 75 to 94 and older than 95 years, respectively). Other deaths were related to mental illness or living in group homes for people with mental illnesses. Preexisting psychologic illness can more than triple the risk of death. A concept in management during a disaster, especially in the response phase, is “the greatest good for the greater number of casualties.” The triage system must be implemented during the immediate response phase to prioritize the patients. Later, after resources have increased, care can be given to most of the victims, and endemic diseases can be further prevented.

Disaster research is crucial for providing valuable information for future disaster planning and prevention. A vulnerability factor is needed for the development of disaster research.

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Aug 25, 2019 | Posted by in EMERGENCY MEDICINE | Comments Off on Disaster and Climate Change

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