The 21st Century climate challenge

4Adapting to the inevitable: national action and international cooperationAn obvious danger is thatthe adaptation needs ofmarginalized communitieswill be overlooked in theface of demands from morepowerful groups with astronger political voicelinking it to public policies aimed at overcominghunger and reducing vulnerability—and towider partnerships with donors.Infrastructural development can be acost-effective route to improved disaster riskmanagement. In rich countries, recognitionthat disaster prevention is more cost-effectivethan cure has been an important factor inshaping government infrastructure investment.Similar cost–benefit principles applyin the developing world. One recent globalstudy estimates that US$1 invested inpre-disaster risk management activities indeveloping countries can prevent US$7 inlosses. 34 National research confirms thisbroad cost–benefit story. In China, theUS$3 billion spent on flood defences in thefour decades up to 2000 is estimated to haveaverted losses of US$12 billion. 35 Evidencefrom a mangrove-planting project designed toprotect coastal populations from storm surgesin Viet Nam estimated economic benefitsthat were 52 times higher than costs. 36Successful adaptation planning has thepotential to avert economy-wide losses. Disasterrisk analysis in Bangladesh provides an insightinto returns to adaptation investments. Usingrisk analysis methods analogous to thosedeployed by the insurance industry, researchersassessed the economic asset losses associatedwith flooding risks today, in 2020 and in 2050,under a range of plausible climate change scenarios.If no adaptation was assumed, the costsassociated with more extreme ‘50-year events’amounted to 7 percent of GDP in 2050. Withadaptation they fell to around 2 percent. 37 Thedifferential translates into potentially large setbacksin agricultural production, employmentand investment, with negative implications forhuman development.Consideration of distributional factors iscritical to adaptation planning. Governmentshave to make tough decisions about where toallocate limited public investment resources.An obvious danger is that the adaptationneeds of marginalized communities will beoverlooked in the face of demands from morepowerful groups with a stronger politicalvoice.Pro-poor adaptation strategies cannot bedeveloped in isolation from wider policies aimedat reducing poverty and overcoming inequality.In Bangladesh, government and donors havestarted to identify adaptation strategies thatreach some of the country’s most marginalizedpeople, such as those living on highly floodpronechar islands. As in other areas, there arestrong cost–benefit grounds for undertakingpro-poor adaptation: the estimated returnon investment in char islands is around 3:1(box 4.1). The cost–benefit case is powerfullyreinforced by basic equity considerations: US$1in the household income of some of Bangladesh’spoorest people has to be attached a higher weightthan, say, US$1 saved by high-income groups.Infrastructure for water managementcan play an important role in enhancing—ordiminishing—the opportunities for humandevelopment. Some of the world’s poorest agriculturalproducers will face some of the toughestclimate change adaptation challenges. Withtheir livelihoods dependent on the timing andduration of rainfall, temperature and water runoffpatterns, the rural poor face immediate riskswith very limited resources. This is especiallytrue for producers dependent on rainfed ratherthan irrigated agriculture. Over 90 percentof sub-Saharan African agriculture is in thiscategory. Moreover, the region has one of thelowest rates of conversion of precipitation intowater flows, partly because of high evaporationand partly because of the lack of an irrigationtradition. 38 Although South Asia has wideraccess to irrigation, two in every three ruralpeople still depend on rainfed agriculture.Agricultural producers operating in waterstressed,rainfed environments already investlabour in developing water harvesting systemsthat conserve rainfall. As climate changeincreases the risks, one of the challenges inadaptation planning is to support these efforts.In many countries, the development of irrigationsystems also has a role to play. In 2005 theEconomic Commission for Africa called for adoubling of the arable area under irrigation by2015. Improved access to irrigation could helpsimultaneously to raise productivity and reduceclimate risks. However, proposals in this area176 HUMAN DEVELOPMENT REPORT 2007/2008