IPCC Report.pdf - Adam Curry

Toward a Sustainable and Resilient FutureChapter 8change mitigation efforts undertaken, and it is possible that theserequirements could increase drastically if levels of climate change exceedsystemic thresholds – whether in geophysical or socioeconomic systems.Practical integration of climate change mitigation and adaption into adevelopment context is complicated because of a differential distributionin costs and benefits (e.g., mitigation benefits are distributed andaccrue globally; adaptation benefits, like disaster risk management, areoften easier to measure locally). In addition, the research and policydiscourses of these three policy domains are quite separated and inareas technically unrelated, and the constituencies and decisionmakersare often different (Wilbanks et al., 2007). In many cases, the challengeof bringing the entire range of issues and options into focus – seekingsynergies and avoiding conflicts – is most likely to occur in discussionsof climate change responses and development objectives in particularplaces: localities and small regions where compliance with national orinternational mitigation agendas provides a logic for local action(Wilbanks, 2003). The following subsections present the urban and ruralcontexts as examples.8.5.2.1. UrbanIn an increasingly urbanized world, global sustainability in the contextof a changing climate will depend on achieving sustainable and climateresilientcities. Urban spatial form is critical for energy consumption,emission patterns, and disaster risk management (Desplat et al., 2009),and it influences where and how residents live and the modes of transportthat they use. Urban planning is a tool that can be used to pursue climatechange mitigation, adaptation, and disaster risk reduction as part of theeveryday development process (Newman and Kenworthy, 1989; Bentoet al., 2005; Handy et al., 2005; Ewing and Rong, 2008; Grazi et al.,2008; Brownstone and Golob, 2009; Glaeser and Kahn, 2010). Urbanform also influences the spatial and social inequalities that largely shapevulnerability, coping, and adaptive capacity (Pelling, 2003; Gusdorfet al., 2008; Leichenko and Solecki, 2008). The historical failure ofurban planning in most developing country cities has had tremendousenvironmental and social consequences (UN-HABITAT, 2009; World Bank,2010a). Also in richer countries, where planning is not comprehensive,maladaptation can take place rather than synergistic risk reduction, forexample, where urban heat wave risk management results in increasedprivate air conditioning without decarbonized energy available (Lindley etal., 2006). Similarly, a denser city may reduce greenhouse gas emissionsbut increase heat wave vulnerability (Hamin and Gurran, 2009).However, since urban forms influence both greenhouse gas emissionsand vulnerability (McEvoy et al., 2006), scope for synergistic planningand action can also be found. For example, managing car use maycontribute to decreased greenhouse gas emissions, but also lower localparticulate pollution and reduce the health impacts of urban heat waves(Dennekamp and Carey, 2010).As yet there is only limited evidence that opportunities for synergisticplanning offered by urbanization are being realized, especially for thosemost marginalized and vulnerable. More typically, urbanizationcompounds environmental problems. As countries urbanize, the risksassociated with economic asset loss tend to increase through rapidgrowth in infrastructure and productive and social assets, while mortalityrisk tends to decrease (Birkmann, 2006). As cities grow, they also modifythe surrounding rural environment, and consequently may generate asignificant proportion of the hazard to which they are also exposed. Forexample, as areas of hinterland are paved over, runoff increases duringstorms, greatly magnifying flood hazards (Mitchell, 1999; Pelling, 1999).As mangroves are destroyed in coastal cities, storm-surge hazard canincrease (Hardoy et al., 2001). Likewise, within urban areas (thoughoften beyond the reach of urban planning), the expansion of informalsettlements can lead to increased local population exposure to landslideand flood hazards (Satterthwaite, 1997; UNDP, 2004). Global riskmodels indicate that expansion of urban risk is primarily due to rapidlyincreasing exposure, which outpaces improvements in capacity toreduce vulnerability (such as through improvements legislating andapplying building standards and land use planning), at least in rapidlygrowing low- and middle-income nations (UNISDR, 2009, 2011). Asa consequence, risk is becoming increasingly urbanized (Mitchell,1999; Pelling, 2003; Leichenko and O’Brien, 2008). There are dramaticdifferences, nonetheless, between developed and developing countries.In most developed countries (and increasingly in a number of cities inmiddle-income countries, e.g., Bogota, Mexico City), risk-reducingcapacities exist that can manage increases in exposure. In contrast, inmuch of the developing world (and particularly in the poorest leastdevelopedcountries where large proportions of the urban population livein unplanned settlements) such capacities are greatly restricted, whilepopulation growth drives exposure. Financial and technical constraintsmatter for risk management, but differences in wealth alone do notexplain differences in risk reduction investments, which also depend onrisk perceptions and political choice (e.g., Satterthwaite, 1998; Hardoyet al., 2001; Hanson et al., 2011).Urban planning can be a vehicle for synergy, but it takes time to producesignificant effects. Synergy in planning requires anticipation of futureclimate change, taking into account how climate will change over manydecades, the uncertainty of this information, the vulnerability of urbansystems, and the capacity of social agents. The Asian Cities ClimateChange Resilience Network found that catalyzing city-level actors toassess these plans are essential, rather than depending on externalexperts or national agencies to prepare urban plans (Tyler et al., 2010).Built forms are difficult to change because they exhibit strong inertiaand irreversibility: when a low-density city is created, transforming itinto a high-density city is a long, expensive, and difficult process(Gusdorf et al., 2008). This point is crucial in the world’s most rapidlygrowing cities, where urban forms of the future are being decided basedon actions taken in the present, and where current trends indicate thatlow-density, automobile-dependent forms of suburban settlement arerapidly expanding (Solecki and Leichenko, 2006). Some work has startedto investigate these aspects of climate change adaptation and mitigation(Newman et al., 1996). At the same time, there are specific opportunitieswhen cities enter periods of large-scale transformation. This is happening460