IPCC Report.pdf - Adam Curry

Changes in Impacts of Climate Extremes: Human Systems and EcosystemsChapter 4more frequent wildfires are probable (an increase in frequency of 60%for a temperature increase of 3°C) in much of South America. In most ofcentral and northern Mexico, the semi-arid vegetation could be replacedby the vegetation of arid regions (Villers and Trejo, 2004). Due to theinterrelated nature of forest fires, deforestation, drought, and climatechange, isolating one of the processes fails to describe the complexityof the interconnected whole.4.4.4.3. Regional CostsClimatic disasters account for the majority of natural disasters in CentralAmerica, with most of its territory located in tropical and equatorial areas.Low-lying states are especially vulnerable to hurricanes and tropicalstorms. In October 1998, Hurricane Mitch, one of the most powerfulhurricanes of the tropical Atlantic Basin of the 20th century, causeddirect and indirect damages to Honduras of US$ 5 billion, equivalent to95% of Honduras’ 1998 GDP (Cardemil et al., 2000). Some literatureindicates that hurricane losses, when corrected for population andwealth in Latin America and the Caribbean, have not increased since the1940s (Pielke Jr. et al., 2003); and that increasing population and assetsat risk are the main reason for increasing impacts.4.4.5. Europe4.4.5.1. IntroductionThis section assesses vulnerability and exposure to climate extremes inEurope, evaluating observed and projected impacts, disasters, and risks.Europe has a higher population density and lower birth rate than anyother continent. It currently has an aging population; life expectancyis high and increasing, and child mortality is low and decreasing(Eurostat, 2010). European exposure to climate- and weather-relatedhazards has increased whereas vulnerability has decreased as a resultof implementation of policy, regulations, and risk prevention andmanagement (EEA, 2008; UNISDR, 2009).4.4.5.2. Heat WavesSummer heat waves have increased in frequency and duration in mostof Europe (Section 3.3.1 and Table 3-2) and have affected vulnerablesegments of European society. During the 2003 heat wave, several tensof thousands of additional heat-related deaths were recorded (see CaseStudy 9.2.1 and Box 4-4). Urban heat islands pose an additional risk tourban inhabitants. Those most affected are the elderly, ill, and sociallyisolated (Kunst et al., 1993; Laschewski and Jendritzky, 2002; seeCase Study 9.2.1). There are mounting concerns about increasing heatintensity in major European cities (Wilby, 2003) because of the largepopulation that inhabits urban areas. Building characteristics, emissionsof anthropogenic heat from air conditioning units and vehicles, as wellas lack of green open areas in some parts of the cities, may exacerbateheat load during heat waves (e.g., Stedman, 2004; Wilby, 2007).However, as high summer temperatures and urban heat waves becomemore common, populations are able to adapt to such ‘expected’temperature conditions, decreasing mortality during subsequent heatwaves (Fouillet et al., 2008).4.4.5.3. Droughts and WildfiresDrought risk is a function of the frequency, severity, and spatial andtemporal extent of dry spells and of the vulnerability and exposure of apopulation and its economic activity (Lehner et al., 2006). InMediterranean countries, droughts can lead to economic damageslarger than floods or earthquakes (e.g., the drought in Spain in 1990affected 6 million people and caused material losses of US$ 4.5 billion;after CRED, 2010). The most severe human consequences of droughtsare often found in semiarid regions where water availability is alreadylow under normal conditions, water demand is close to, or exceeds,natural availability, and/or society lacks the capacity to mitigate oradapt to drought (Iglesias et al., 2009). Direct drought impacts affectall forms of water supply (municipal, industrial, and agricultural).Other sectors and systems affected by drought occurrence arehydropower generation, tourism, forestry, and terrestrial and aquaticecosystems.Forest fire danger (length of season, frequency, and severity) dependson the occurrence of drought. There is medium confidence in observedchanges in drought in Europe (Table 3-2). Projections indicate increasingdryness in central Europe and the Mediterranean, with no major changein Northern Europe (medium confidence) (see Table 3-3). In theMediterranean, an increase in dryness may lead to increased dominanceof shrubs over trees (Mouillot et al., 2002); however, it does not translatedirectly into increased fire occurrence or changes in vegetation (Thonickeand Cramer, 2006). Analysis of post-fire forest resilience contributes toidentifying ‘risk hotspots’ where post-fire management measuresshould be applied as a priority (Arianoutsou et al., 2011).4.4.5.4. Coastal FloodingCoastal flooding is an important natural disaster, since many Europeanslive near the coasts. Storm surges can be activated as a result of winddrivenwaves and winter storms (Smith et al., 2000), whereas long-termprocesses are linked to global mean sea level rise (Woodworth et al.,2005). Locations currently experiencing adverse impacts such as coastalerosion and inundation will continue to do so in the future (see Section3.5.5). Expected sea level rise is projected to have impacts on Europe’scoastal areas including land loss, groundwater and soil salinization, anddamage to property and infrastructure (Devoy, 2008). Hinkel et al.(2010) found that the total monetary damage in coastal areas of theMember Countries of the European Union caused by flooding, salinityintrusion, land erosion, and migration is projected to rise withoutadaptation by 2100 to roughly € 17 billion per year under the A2 and256