The 21st Century climate challenge

Research carried out for this report underlinesjust how potent these traps can be. Usingmicrolevel household data we examined some ofthe long-term impacts of climate-shocks in thelives of the poor. In Ethiopia and Kenya, twoof the world’s most drought-prone countries,children aged five or less are respectively 36 and 50percent more likely to be malnourished if they wereborn during a drought. For Ethiopia, that translatesinto some 2 million additional malnourishedchildren in 2005. In Niger, children aged two orless born in a drought year were 72 percent morelikely to be stunted. And Indian women bornduring a flood in the 1970s were 19 percent lesslikely to have attended primary school.The long-run damage to human developmentgenerated through climate shocks isinsufficiently appreciated. Media reporting ofclimate-related disasters often plays an importantrole in informing opinion—and in capturing thehuman suffering that comes with climate shocks.However, it also gives rise to a perception thatthese are ‘here-today-gone-tomorrow’ experiences,diverting attention from the long-runhuman consequences of droughts and floods.Climate change will not announce itselfas an apocalyptic event in the lives of thepoor. Direct attribution of any specific eventto climate change will remain impossible.However, climate change will steadily increasethe exposure of poor and vulnerable householdsto climate-shocks and place increasedpressure on coping strategies, which, overtime, could steadily erode human capabilities.We identify five key transmission mechanismsthrough which climate change could stalland then reverse human development:• Agricultural production and food security.Climate change will affect rainfall, temperatureand water availability for agriculturein vulnerable areas. For example, droughtaffectedareas in sub-Saharan Africa couldexpand by 60–90 million hectares, withdry land zones suffering losses of US$26billion by 2060 (2003 prices), a figure inexcess of bilateral aid to the region in 2005.Other developing regions—including LatinAmerica and South Asia—will also experiencelosses in agricultural production,undermining efforts to cut rural poverty. Theadditional number affected by malnutritioncould rise to 600 million by 2080.• Water stress and water insecurity. Changedrun-off patterns and glacial melt will addto ecological stress, compromising flows ofwater for irrigation and human settlements inthe process. An additional 1.8 billion peoplecould be living in a water scarce environmentby 2080. Central Asia, Northern China andthe northern part of South Asia face immensevulnerabilities associated with the retreatof glaciers—at a rate of 10–15 metres a yearin the Himalayas. Seven of Asia’s great riversystems will experience an increase in flowsover the short term, followed by a decline asglaciers melt. The Andean region also facesimminent water security threats with the collapseof tropical glaciers. Several countries inalready highly water-stressed regions such asthe Middle East could experience deep lossesin water availability.• Rising sea levels and exposure to climatedisasters. Sea levels could rise rapidly withaccelerated ice sheet disintegration. Globaltemperature increases of 3–4°C could resultin 330 million people being permanently ortemporarily displaced through flooding.Over 70 million people in Bangladesh, 6million in Lower Egypt and 22 million inViet Nam could be affected. Small islandstates in the Caribbean and Pacific couldsuffer catastrophic damage. Warming seaswill also fuel more intense tropical storms.With over 344 million people currently exposedto tropical cyclones, more intensivestorms could have devastating consequencesfor a large group of countries. The 1 billionpeople currently living in urban slums onfragile hillsides or flood-prone river banksface acute vulnerabilities.• Ecosystems and biodiversity. Climate changeis already transforming ecological systems.Around one-half of the world’s coral reefsystems have suffered ‘bleaching’ as a resultof warming seas. Increasing acidity in theoceans is another long-term threat to marineecosystems. Ice-based ecologies havealso suffered devastating climate changeGlobal temperatureincreases of 3–4°C couldresult in 330 million peoplebeing permanently ortemporarily displacedthrough floodingHUMAN DEVELOPMENT REPORT 2007/2008 9