Risk Driver

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Climate change

Climate change can increase disaster risk in a variety of ways - by altering the frequency and intensity of hazard events, affecting vulnerability to hazards, and changing exposure patterns.

Disaster risk is magnified by climate change; it can increase the hazard while at the same time decreasing the resilience of households and communities.

Climate change refers to a change in the climate that persists for decades or longer, arising from either natural causes or human activity (adapted from IPCC, 2007 in UNISDR, 2009). Climate change is already modifying the frequency and intensity of many weather-related hazards (IPCC, 2014) as well as steadily increasing the vulnerability and eroding the resilience of exposed populations that depend arable land, access to water, and stable mean temperatures and rainfall (UNISDR, 2015a). Risk to weather-related hazards is concentrated in low and middle-income countries (UNISDR, 2009). Although the precise impact of climate change is not certain, and it is important to be aware that not all areas will be impacted in the same way, projected impacts of climate change that will drive disaster risk include (UNISDR, 2009b):

  • Decreasing agricultural yields in warmer environments due to heat stress, which has major implications for the livelihoods of the rural poor, and can also lead to migration to urban areas, which increases the population exposed to natural hazards in such locations (UNISDR, 2015).
  • Rising sea levels, which will increase hazards in low-lying coastal areas - the population of coastal areas has grown faster than the overall increase in global population (UNISDR, 2009).
  • More severe and frequent extreme precipitation events, which will intensify existing patterns of extensive risk when combined with the increases in the population and assets exposed due to migration from rural areas.
  • Changes in the geographic distribution of weather-related hazards, which may lead to new patterns of risk.
  • Decreasing resilience, which is likely to disproportionately affect poorer countries and communities meaning that climate change is also a driver of poverty.


Impacts of sea level rise in urban areas in Africa: the case of Lagos

Repeatedly facing grave disasters © Heinrich-Boll-Stiftung CC BY-SA 2.0


The inadequate drainage network, sewers, and wastewater management systems in Lagos, Nigeria, are likely to only worsen as climate change increases sea level rise in urban areas.


Risk associated with weather-related hazards is disproportionately concentrated in developing countries and within these countries in poorer sectors of the population (UNISDR, 2009b). Poverty and constrained access to productive assets mean that rural livelihoods that depend on agriculture and other natural resources are vulnerable to even slight variations in weather and seasonality (UNISDR, 2009b).

The impact of climate change in rural and urban areas in is intimately linked. As the sustainability of rural livelihoods declines and disaster risk increases, it is possible that increased rural to urban migration may occur. Related to climate change, in rural areas more frequent and extreme droughts, as well as changes in mean temperature and precipitation levels will cause further stress to these already vulnerable livelihoods (UNISDR, 2009b).


Climate change forced migration from urbanized areas: the future for India

Washing laundry in the Ganges at sunset. © mIss_mIllIons CC BY 2.0


Climate change is likely to increase natural hazards in densely populated regions of India, forcing migration from urbanized centres, to locations unprepared to receive new migrants.



Development continues in Miami despite future sea level rise inundation

Turkey Point Nuclear Power Plant threatened by sea level rise © UNISDR, 2015

United States of America

Despite the sea level rise inundation, and current and future severe storm surges, development continues unabated in Miami's coastal area.


Opportunities for building resilience

It is not inevitable that climate change leads to increasing disaster risk (UNISDR, 2009b).

It is important to differentiate between climate change and the disaster risks associated with climate change (UNISDR, 2009b). However, as with all the underlying risk drivers, because climate change is so closely linked to a number of other risk drivers, it must be addressed in combination with reducing these other drivers of risk (UNISDR, 2009b). If these drivers are not addressed, disaster risk will continue to increase even if climate change is successfully mitigated (UNISDR, 2009b).

Addressing the underlying risk drivers is key to both disaster risk reduction and climate change adaptation (UNISDR, 2009b).

Patterns of risk that may be driven by climate change are also related to factors such as the growth of informal settlements in exposed areas, lack of investment in drainage infrastructure, and deficiencies in urban and local governance (2009b). By addressing these, we can build resilience to climate change (2009b).

Climate change has emerged as a sector in itself at the national, regional and international levels, with its own institutional arrangements, global framework, and funding mechanisms (UNISDR, 2015a). Since the formulation of the Nairobi Work Programme at the Conference of the Parties in 2006, a plethora of strategies, frameworks and funding mechanisms has certainly created the impression of convergence and coherence of climate change agendas with those of disaster risk reduction and sustainable development (UNEP, 2014 in UNISDR, 2015a).

Several countries, such as the Philippines, Vietnam and others in the Pacific region, have managed to take the opportunity to effectively merge regulation and technical guidelines as well as national policy frameworks and budgets for disaster risk reduction and climate change adaptation. However, those countries remain the minority, and most national policies, despite citing the respective other domain, maintain distinct boundaries in concepts, plans, methodologies, reporting lines, responsibilities, budgets, and other areas (SEI, 2014 in UNISDR, 2015a).


Merging DRR and climate change adaptation in Viet Nam

Agricultural research helps farmers in Vietnam grow more rice and counteract the impacts of climate change on food security. © Philippe Berry, IFPRI, USAID U.S. Agency for International Development, CC BY-NC-ND 2.0

Viet Nam

Viet Nam has increased collaboration between disaster risk reduction and climate change adaptation agencies in recent years.

SOURCE: SEI, 2014; MARC, 2014


Related Sections on Preventionweb

Components of Risk

Disaster Risk
Risk is a forward looking concept, so disaster risk can be understood as the likelihood (or probability) of loss of life, injury or destruction and damage from a disaster in a given period of time (adapted from UNISDR, 2015a).
A dangerous event that may cause loss of life, injury or other health impacts, as well as damage and loss to property, infrastructure, livelihoods and services, social and economic disruption and, or environmental damage is known as a hazard (UNISDR, 2009b).
The presence and number of people, property, livelihoods, systems or other elements in hazard areas (and so thereby subject to potential losses) is known as exposure (UNISDR, 2009b and IPCC, 2012).
The name given to the set of characteristics and circumstances of a community, system or asset that make it susceptible to the damaging effects of a hazard is vulnerability.

Risk Drivers

Climate change
Climate change can increase disaster risk in a variety of ways – by altering the frequency and intensity of hazard events, affecting vulnerability to hazards, and changing exposure patterns.
Environmental degradation
Environmental degradation is both a driver and consequence of disasters, reducing the capacity of the environment to meet social and ecological needs.
Globalized economic development
Globalized economic development can lead to increased exposure of assets in hazard-prone areas, leading to further increases in intensive risk if not managed.
Poverty & inequality
Poverty is both a driver and consequence of disasters, and the processes that further disaster risk related poverty are permeated with inequality
Poorly planned urban development
Whether or not disaster risk is factored into investment decisions in urban development will have a decisive influence on the future of disaster risk reduction.
Weak governance
Governance of disaster risk management must be improved, not only through specialized and stand-alone sectors, but also through strengthened governance arrangements across sectors and territories in order to address disaster risk.

Key Concepts

Capacity refers to all the strengths, attributes and resources available within a community, organization or society that can be used to achieve agreed goals.
Deterministic & probabilistic risk
Deterministic risk considers the impact of a single risk scenario, whereas probabilistic risk considers all possible scenarios, their likelihood and associated impacts
Direct & indirect losses
Direct disaster losses refer to the number of people killed and the damage to buildings, infrastructure and natural resources. Indirect disaster losses include declines in output or revenue and generally arise from disruptions to the flow of goods and services.
Disaster risk reduction & disaster risk management
DRR is the policy objective of anticipating and reducing risk. Although often used interchangeably with DRR, DRM can be thought of as DRR implementation, since it describes the actions that aim to achieve the objective of reducing risk.
Intensive & extensive risk
Extensive risk is used to describe the risk of low-severity, high-frequency disasters, mainly but not exclusively associated with highly localized hazards. Intensive risk is used to describe the risk of high-severity, mid to low-frequency disasters, mainly associated with major hazards.
Resilience refers to the ability of a system, community or society exposed to hazards to resist, absorb, accommodate to and recover from the effects of a hazard in a timely and efficient manner.
Sovereign risk
Sovereign risk is the economic impact a government would face in the event of a disaster.


Risk modeling
We need data on hazard, exposure, vulnerability and losses in order to understand and assess disaster risk.


Data and statistics are important in understanding the impacts and costs of disasters.
Data Viewers
Open access, online data viewers present hazard, disaster, and risk data in an easily accessible manner.