The 21st Century climate challenge

more likely. Evidence from the past provides uswith insights into the processes that will drivethese reversals, but the future under climatechange will not look like the past. Setbacksfor human development will be non-linear,with powerful mutually reinforcing feedbackeffects. Losses in agricultural productivity willreduce income, diminishing access to healthand education. In turn, reduced opportunitiesin health and education will restrict marketopportunities and reinforce poverty. At a morefundamental level, climate change will erodethe ability of the world’s most vulnerable peopleto shape decisions and processes that impact ontheir lives.Catastrophic human development setbacksare avoidable. There are two requirements forchanging the 21 st Century scenario to a morefavourable direction. The first is climate changemitigation. Without early and deep cuts inemissions of CO 2, dangerous climate change willhappen—and it will destroy human potential ona vast scale. The consequences will be reflected insurging inequalities within and across countriesand rising poverty. Rich countries may escapethe immediate effects. They will not escapethe consequences of the anger, resentment andtransformation of human settlement patternsthat will accompany dangerous climate changein poor countries.The second requirement for averting thethreats set out in this chapter is adaptation.No amount of mitigation will protectvulnerable people in developing countriesfrom the incremental climate change risks thatthey face today, or from the global warmingto which the world is already committed.Increased risk exposure is inevitable—humandevelopment reversals are not. Adaptation isultimately about building the resilience of theworld’s poor to a problem largely created bythe world’s richest nations.Catastrophic humandevelopment setbacksare avoidable2Climate shocks: risk and vulnerability in an unequal worldHUMAN DEVELOPMENT REPORT 2007/2008 107