IPCC Report.pdf - Adam Curry

Chapter 2Determinants of Risk: Exposure and VulnerabilityThe built environment can be both protective of, and subject to, climateextremes. Inadequate structures make victims of their occupants and,conversely, adequate structures can reduce human vulnerability. Thecontinuing toll of deaths and injuries in unsafe schools (UNISDR,2009a), hospitals and health facilities (PAHO/World Bank, 2004),domestic structures (Hewitt, 1997), and infrastructure more broadly(Freeman and Warner 2001) are indicative of the vulnerability of manyparts of the built environment. In a changing climate, more variableand with potentially more extreme events, old certainties about theprotective ability of built structures are undermined.The increase in the number and extent of informal settlements or slums(UN-HABITAT, 2003; Utzinger and Keiser, 2006) is important because theyare often located on marginal land within cities or on the peripherybecause of the lack of alternative locations or the fact that areas closeto river systems or areas at the coast are sometimes state land that canbe more easily accessed than private land. Because of their location,slums are often exposed to hydrometeorological-related hazards suchas landslides (Nathan, 2008) and floods (Bertoni, 2006; Colten, 2006;Aragon-Durand, 2007; Douglas et al., 2008; Zahran et al., 2008).Vulnerability in informal settlements can also be elevated because ofpoor health (Sclar et al., 2005), livelihood insecurity (Kantor and Nair,2005), lack of access to service provision and basic needs (such asclean water and good governance), and a reduction in the capacity offormal players to steer developments and adaptation initiatives in acomprehensive, preventive, and inclusive way (Birkmann et al., 2010b).Lagos, Nigeria (Adelekan, 2010), and Chittagong, Bangladesh (Rahmanet al., 2010), serve as clear examples of where an upward trend in thearea of slums has resulted in an increase in the exposure of slumdwellers to flooding. Despite the fact that rapidly growing informaland poor urban areas are often hotspots of hazard exposure, for anumber of locations the urban poor have developed more or lesssuccessful coping and adaptation strategies to reduce their vulnerabilityin dealing with changing environmental conditions (e.g., Birkmann et al.,2010b).Globally, the pressure for urban areas to expand onto flood plains andcoastal strips has resulted in an increase in exposure of populations toriverine and coastal flood risk (McGranahan et al., 2007; Nicholls et al.,2011). For example, intensive and unplanned human settlements inflood-prone areas appear to have played a major role in increasingflood risk in Africa over the last few decades (Di Baldassarre et al.,2010). As urban areas have expanded, urban heat has become amanagement and health issue (for more on this see Section 2.5.2.3 andChapters 3, 5, and 9). For some cities there is clear evidence of a recenttrend in loss of green space (Boentje and Blinnikov, 2007; Sanli et al.,2008; Rafiee et al., 2009) due to a variety of reasons including plannedand unplanned urbanization with the latter driven by internal and externalmigration resulting in the expansion of informal settlements. Suchchanges in green space may increase exposure to extreme climateevents in urban areas through decreasing runoff amelioration, urbanheat island mitigation effects, and alterations in biodiversity (Wilbyand Perry, 2006).While megacities have been associated with increasing hazard for sometime (Mitchell, 1999a), small cities and rural communities (see nextsection) are potentially more vulnerable to disasters than big cities ormegacities, since megacities have considerable resources for dealingwith hazards and disasters (Cross, 2001) and smaller settlements areoften of lower priority for government spending.Urbanization itself is not always a driver for increased vulnerability.Instead, the type of urbanization and the context in which urbanizationis embedded defines whether these processes contribute to an increaseor decrease in people’s vulnerability.2.5.1.3.2. The rural environmentMany rural livelihoods are reliant to a considerable degree on theenvironment and natural resource base (Scoones, 1998), and extremeclimate events can impact severely on the agricultural sector (Saldaña-Zorrilla, 2007). However, despite the separation here, the urban andthe rural are inextricably linked. Inhabitants of rural areas are oftendependent on cities for employment, as a migratory destination of lastresort, and for health care and emergency services. Cities depend onrural areas for food, water, labor, ecosystem services, and otherresources. All of these (and more) can be impacted by climate-relatedvariability and extremes including changes in these associated withclimate change. In either case, it is necessary to identify the manyexogenous factors that affect a household’s livelihood security.Eakin’s (2005) examination of rural Mexico presents empirical findingsof the interactions (e.g., between neoliberalism and the opening up ofagricultural markets, and the agricultural impacts of climatic extremes),which amplify or mitigate risky outcomes. The findings point to economicuncertainty over environmental risk, which most influences agriculturalhouseholds’ decisionmaking. However, there is not a direct and inevitablelink between disaster impact and increased impoverishment of a ruralpopulation. In Nicaragua, Jakobsen (2009) found that a household’sprobability of being poor in the years following Hurricane Mitch was notaffected by whether it was living in an area struck but by factors such asoff-farm income, household size, and access to credit. Successful copingpost-Hurricane Mitch resulted in poor households regaining most oftheir assets and resisting a decline into a state of extreme poverty.However, longer-term adaptation strategies, which might have lifted themout of the poverty category, eluded the majority and were independentof having experienced Hurricane Mitch. Thus, while poor (rural) householdsmay cope with the impacts of a disaster in the relatively short term,their level of vulnerability, arising from a complex of environmental,social, economic, and political factors, is such that they cannot escapethe poverty trap or fully reinstate development gains.In assessing the material on exposure and vulnerability to climateextremes in urban and rural environments it is clear that there is nosimple, deterministic relationship; it is not possible to show that eitherrural or urban environments are more vulnerable (or resilient). In79