The 21st Century climate challenge

2Climate shocks: risk and vulnerability in an unequal worldFigure 2.7Latin America’sretreating glaciersPeru2006 1,370sq.km 1970 1,958sq.kmBolivia2006 396sq.km 1975 562sq.kmEcuador2006 79sq.km 1976 113sq.kmColombia2006 76sq.km 1950 109sq.kmVenezuela2006 2sq.km 1950 3sq.kmSource: Painter 2007, based on data from the Andean Community.melting poses a real and imminent threat tohuman development (box 2.9).Rising seas and exposure toextreme weather risksThe IPCC projection: It is likely that tropicalcyclones—typhoons and hurricanes—willbecome more intense as oceans warm, withhigher peak speeds and heavier precipitation.All typhoons and hurricanes are driven byenergy released from the sea—and energy levelswill rise. One study has found a doubling ofpower dissipation in tropical cyclones over thepast three decades. 81 Sea levels will continue torise, though there is uncertainty about by howmuch. Oceans have absorbed over 80 percentof the increased heat generated by globalwarming, locking the world into continuedthermal expansion. 82 Drought and floods willbecome more frequent and widespread acrossmuch of the world.The human development projection: Emerging riskscenarios threaten many dimensions of humandevelopment. Extreme and unpredictable weatherevents are already a major source of poverty. Theybring near-term human insecurity and destroylong-term efforts aimed at raising productivity,improving health and developing education,perpetuating the low human development trapsdescribed earlier in this chapter. Many countrieshave large and highly vulnerable populations thatwill face a steep increase in climate-related risks,with people living in coastal areas, river deltas,urban slums and drought-prone regions facingimmediate threats.Climate change is only one of the forcesthat will influence the profile of risk exposurein the decades ahead. Other global processes—ecological stress, urbanization and populationgrowth among them—will also be important.However, climate change will reconfigurepatterns of risk and vulnerability across manyregions. The combination of increasing climatehazards and declining resilience is likely toprove a lethal mix for human development.Any increase to climate-related riskexposure has to be assessed against the backdropof current exposure. That backdrop includes thefollowing numbers of people facing climaterelatedhazards: 83• 344 million exposed to tropical cyclones;• 521 million exposed to floods;• 130 million exposed to droughts;• 2.3 million exposed to landslides.As these figures indicate, even smallincreases to risk over time will affect verylarge numbers of people. Like climate changeitself, the potential linkages between changingweather patterns and evolving trends in risk98 HUMAN DEVELOPMENT REPORT 2007/2008