The 21st Century climate challenge

Developing countries arelikely to become more2.2 Looking ahead—old problems and new climatechange risksdependent on imports2Climate shocks: risk and vulnerability in an unequal worldfrom the rich world, withtheir farmers losing marketshares in agricultural trade“Prediction is very difficult, especially if it’sabout the future,” commented the Danishphysicist and Nobel laureate Niels Bohr. Theobservation applies with special force to climate.However, while specific events are uncertain,changes in average conditions associated withclimate change can be predicted.The IPCC’s Fourth Assessment Reportprovides a best-estimate set of projectionsfor future climate. These projections are notweather forecasts for individual countries.What they offer is a range of probabilities forbroad changes in climate patterns. The underlyingstory has important implications for humandevelopment. Over the decades ahead there willbe a steady increase in human exposure to suchevents as droughts, floods and storms. Extremeweather events will become more frequent andmore intense, with less certainty and predictabilityin the timing of monsoons and rainfall.In this section we provide an overview ofthe links from the IPCC’s projections to humandevelopment outcomes. 44 We focus on ‘likely’and ‘very likely’ outcomes for climate, definedrespectively as results with an occurrence probabilityin excess of 66 and 90 percent. 45 Whilethese outcomes relate only to average global andregional conditions, they help to identify emergingsources of risk and vulnerability.Agricultural productionand food securityIPCC projection: Increases in precipitationin high latitudes and decreases in sub-tropicallatitudes, continuing the current patternof drying in some regions. Warming is likelyto be above the global average throughoutsub-Saharan Africa, eastern Asia and SouthAsia. In many water-scarce regions, climatechange is expected to further reduce wateravailability through increased frequency ofdroughts, increased evaporation and changesin patterns of rainfall and runoff. 46Human development projection: Major lossesin agricultural production leading to increasedmalnutrition and reduced opportunities forpoverty reduction. Overall, climate change willlower the incomes and reduce the opportunitiesof vulnerable populations. By 2080, the numberof additional people at risk of hunger could reach600 million—twice the number of people livingin poverty in sub-Saharan Africa today. 47Global assessments of the impact of climatechange on agriculture obscure very largevariations across and even within countries.In broad terms, climate change will increasethe risks to and reduce the productivity ofdeveloping country agriculture. In contrast,production could be boosted in developedcountries, so that the distribution of world foodproduction may shift. Developing countries arelikely to become more dependent on importsfrom the rich world, with their farmers losingmarket shares in agricultural trade. 48Emerging patterns of climate change riskin agriculture will have important implicationsfor human development. Around threein every four people in the world living on lessthan US$1 a day reside in rural areas. Theirlivelihoods depend on smallholder agriculture,farm employment, or pastoralism. 49 The sameconstituency also accounts for most of the 800million people in the world who are malnourished.Climate change impacts on agriculturewill thus have important multiplier effects.Agricultural production and employmentunderpin many national economies (table 2.4).The agricultural sector accounts for over onethirdof export earnings in around 50 developingcountries and for almost half of employment inthe developing world. 50 In sub-Saharan Africain particular, economic growth rates are closelytied to rainfall, as demonstrated by the experienceof Ethiopia (figure 2.5). Moreover, everyUS$1 generated in agriculture in sub-SaharanAfrica is estimated to generate up to US$3 inthe non-agricultural sector. 5190 HUMAN DEVELOPMENT REPORT 2007/2008