IPCC_Managing Risks of Extreme Events.pdf - Climate Access

Chapter 4Changes in Impacts of Climate Extremes: Human Systems and Ecosystems82.760.247.88.9NORTHAMERICA6.216.411.74.89.6EUROPEPopulation exposedin 2050 in millions0.50m SLR0.15m SLRCurrent populationexposed7.4 5.64.6SOUTHAMERICA5.8 3.82.8AFRICAASIA2.7 2.31.8OCEANIAHeight of columns represents the number of exposed persons.Figure 4-5 | For low-elevation coastal areas, current and future (2050) population exposure to inundation in the case of the 1-in-100-year extreme storm for sea level rise of0.15 m and for sea level rise of 0.50 m due to the partial melting of the Greenland and West Antarctic Ice Sheets. Data from Lenton et al., 2009.change alters the frequency and severity of extremes, for example, anincrease in heavy rainfalls may affect the capacity and maintenance ofstorm water, drainage, and sewerage infrastructure (Douglas et al., 2008).In some infrastructure, secondary risks in case of extreme weather maycause additional hazards (e.g., extreme rainfall can damage dams). Thesame is true for industrial and mining installations containing hazardoussubstances (e.g., heavy rainfall is the main cause of tailings dam failure,accounting for 25% of incidents worldwide and 35% in Europe; Rico etal., 2008).In many parts of the world, including Central Asia and parts of Europe,aging infrastructure, high operating costs, low responsiveness tocustomers, and poor access to capital markets may limit the operabilityof sewerage systems (Evans and Webster, 2008). Moreover, most urbancenters in sub-Saharan Africa and in Asia have no sewers (Hardoy et al.,2001). Current problems of pollution and flooding will be exacerbatedby an increase in climatic and weather extremes (e.g., intense rainfall;see Table 3-3 for projected regional changes).Major settlements are dependent on lengthy infrastructure networks forwater, power, telecommunications, transport, and trade, which are exposedto a wide range of extreme events (e.g., heavy precipitation and snow,gale winds). Modern logistics systems are intended to minimize slackand redundancies and as a result are particularly vulnerable to disruptionby extreme events (Love et al., 2010).Transport infrastructure is vulnerable to extremes in temperature,precipitation/river floods, and storm surges, which can lead to damagein roads, rail, airports, and ports. Impacts on coastal infrastructure, onservices, and particularly on ports, key nodes of international supplychains, are expected (e.g., Oh and Reuveny, 2010). This may have farreachingimplications for international trade, as more than 80% of globaltrade in goods (by volume) is carried by sea (UNCTAD, 2009). All coastalmodes of transportation are considered vulnerable, but exposure andimpacts will vary, for example, by region, mode of transportation, location/elevation, and condition of transport infrastructure (NRC, 2008; UNCTAD,2009). Coastal inundation due to storm surges and river floods can affectterminals, intermodal facilities, freight villages, storage areas, and cargoand disrupt intermodal supply chains and transport connectivity (seeFigure 4-6). These effects would be of particular concern to small islandstates, whose transportation facilities are mostly located in low-elevationcoastal zones (UNCTAD, 2009; for further examples, see Love et al., 2010).Regarding road infrastructure, Meyer (2008) pointed to bridges andculverts as vulnerable elements in areas with projected increases inheavy precipitation. Moreover, the lifetime of these rigid structures islonger than average road surfaces and they are costly to repair orreplace. Increased temperatures could reduce the lifetime of asphalt onroad surfaces (Meizhu et al., 2010). Extreme temperature may causeexpansion and increased movement of concrete joints, protectivecladding, coatings, and sealants on bridges and airport infrastructure,impose stresses in the steel in bridges, and disrupt rail travel (e.g., Arkelland Darch, 2006). Nevertheless, roads and railways are typically replacedevery 20 years and can accommodate climate change at the time ofreplacement (Meyer, 2008).Electricity transmission infrastructure is also vulnerable to extremestorm events, particularly wind and lightning, and in some cases heat249