Executive Summary

The severity of the impacts of extreme and non-extreme weather and climate events depends strongly on the level of vulnerability and exposure to these events (high confidence). [2.2.1, 2.3, 2.5] Trends in vulnerability and exposure are major drivers of changes in disaster risk, and of impacts when risk is realized (high confidence). [2.5] Understanding the multi-faceted nature of vulnerability and exposure is a prerequisite for determining how weather and climate events contribute to the occurrence of disasters, and for designing and implementing effective adaptation and disaster risk management strategies. [2.2, 2.6]

Vulnerability and exposure are dynamic, varying across temporal and spatial scales, and depend on economic, social, geographic, demographic, cultural, institutional, governance, and environmental factors (high confidence). [2.2, 2.3, 2.5] Individuals and communities are differentially exposed and vulnerable and this is based on factors such as wealth, education, race/ethnicity/religion, gender, age, class/caste, disability, and health status. [2.5] Lack of resilience and capacity to anticipate, cope with, and adapt to extremes and change are important causal factors of vulnerability. [2.4]

Extreme and non-extreme weather and climate events also affect vulnerability to future extreme events, by modifying the resilience, coping, and adaptive capacity of communities, societies, or social-ecological systems affected by such events (high confidence). [2.4.3] At the far end of the spectrum – low-probability, highintensity events – the intensity of extreme climate and weather events and exposure to them tend to be more pervasive in explaining disaster loss than vulnerability in explaining the level of impact.

Executive Summary

This chapter assesses how countries are managing current and projected disaster risks, given knowledge of how risks are changing with observations and projections of weather and climate extremes [Table 3–2, 3.3], vulnerability and exposure [4.3], and impacts [4.4]. It focuses on the design of national systems for managing such risks, the roles played by actors involved in the system, and the functions they perform, acknowledging that complementary actions to manage risks are also taken at local and international level as described in Chapters 5 and 7.

National systems are at the core of countries' capacity to meet the challenges of observed and projected trends in exposure, vulnerability, and weather and climate extremes (high agreement, robust evidence). Effective national systems comprise multiple actors from national and sub-national governments, private sector, research bodies, and civil society, including community-based organizations, playing differential but complementary roles to manage risk according to their accepted functions and capacities. These actors work in partnership across temporal, spatial, administrative, and social scales, supported by relevant scientific and traditional knowledge. Specific characteristics of national systems vary between countries and across scales depending on their socio-cultural, political, and administrative environments and development status. [6.2]

The national level plays a key role in governing and managing disaster risks because national government is central to providing risk management-related public goods as it commonly maintains financial and organizational authority in planning and implementing these goods (high agreement, robust evidence). National governments are charged with the provision of public goods such as ensuring the economic and social well-being, safety, and security of their citizens from disasters, including the protection of the poorest and most vulnerable citizens. They also control budgetary allocations as well as creating legislative frameworks to guide actions by other actors.

Context

This Summary for Policymakers presents key findings from the Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). The SREX approaches the topic by assessing the scientific literature on issues that range from the relationship between climate change and extreme weather and climate events (‘climate extremes’) to the implications of these events for society and sustainable development. The assessment concerns the interaction of climatic, environmental, and human factors that can lead to impacts and disasters, options for managing the risks posed by impacts and disasters, and the important role that non-climatic factors play in determining impacts. Box SPM.1 defines concepts central to the SREX.

The character and severity of impacts from climate extremes depend not only on the extremes themselves but also on exposure and vulnerability. In this report, adverse impacts are considered disasters when they produce widespread damage and cause severe alterations in the normal functioning of communities or societies. Climate extremes, exposure, and vulnerability are influenced by a wide range of factors, including anthropogenic climate change, natural climate variability, and socioeconomic development (Figure SPM.1). Disaster risk management and adaptation to climate change focus on reducing exposure and vulnerability and increasing resilience to the potential adverse impacts of climate extremes, even though risks cannot fully be eliminated (Figure SPM.2). Although mitigation of climate change is not the focus of this report, adaptation and mitigation can complement each other and together can significantly reduce the risks of climate change. [SYR AR4, 5.3]

Executive Summary

Disasters are most acutely experienced at the local level (high agreement, robust evidence). The reality of disasters in terms of loss of life and property occurs in local places and to local people. These localized impacts can then cascade to have national and international consequences. In this chapter, local refers to a range of places, social groupings, experience, management, institutions, conditions, and sets of knowledge that exist at a sub-national scale. [5.1]

Developing strategies for disaster risk management in the context of climate change requires a range of approaches, informed by and customized to specific local circumstances (high agreement, robust evidence). These differences and the context (national to global, urban to rural) in which they are situated shape local vulnerability and local impacts. [5.1]

The impacts of climate extremes and weather events may threaten human security at the local level (high agreement, medium evidence). Vulnerability at the local level is attributed to social, political, and economic conditions and drivers including localized environmental degradation and climate change. Addressing disaster risk and climate extremes at the local level requires attention to much wider issues relating to sustainable development. [5.1]

While structural measures provide some protection from disasters, they may also create a false sense of safety (high agreement, robust evidence). Such measures result in increased property development, heightened population density, and more disaster exposure. Current regulations and design levels for structural measures may be inadequate under conditions of climate change. [5.3.2]

The Intergovernmental Panel on Climate Change (IPCC, 2007) definition of climate change refers to any change in climate over time, whether it is due to natural variability or is a result of human activity. Climate and non-climatic factors interact to produce both opportunities and disasters. It is the goal of good adaptation practices to take advantage of such opportunities and to reduce associated risks. There are substantial vulnerabilities to hurricanes along the Atlantic seaboard of the United States. The major concentrations of vulnerable economic activity and capital (with capital stock greater than US$100 billion) are located in areas affected by hurricanes, including the coastal cities of Miami, New Orleans, Houston, and Tampa, three of which have been hit by major storms in the past 15 years. The year 2005 was an economic outlier because the cost per unit of hurricane power was high, but not because the power was extraordinarily high.

Adaptation to climate change must account for a variety of timescales if it is to be effectively embedded into development plans. In any event, a more robust formulation for integrating disaster risks into sustainable development is important in an uncertain and changing environment. Key informational needs for mainstreaming climate change and adaptation into development plans include knowledge of the spatial and temporal characteristics of climatic extremes and the integration of loss estimates with projections of such extremes.