The 21st Century climate challenge

esult of burning and loss of biomass. Data in thisarea are more uncertain than for other sectors.However, best estimates suggest that around 6Gt CO 2are released annually. 51 According tothe IPCC, the share of CO 2originating fromdeforestation ranges between 11 and 28 percentof total emissions. 52One of the conclusions to emerge fromthe sectoral analysis of carbon footprintsis that mitigation aimed at reducing CO 2emissions from power generation, transport anddeforestation is likely to generate high returns.National carbon footprints can bemeasured in terms of stocks and flows.National footprint depth is closely relatedto historic and current energy use patterns.While the aggregate footprint of thedeveloping world is becoming deeper, historicresponsibility for emissions rests heavily withthe developed world.Rich countries dominate the overallemissions account (figure 1.4). Collectively,they account for about 7 out of every 10 tonnesof CO 2that have been emitted since the startof the industrial era. Historic emissionsamount to around 1,100 tonnes of CO 2percapita for Britain and America, comparedwith 66 tonnes per capita for China and 23tonnes per capita for India. 53 These historicemissions matter on two counts. First, asnoted earlier, cumulative past emissionsdrive today’s climate change. Second, theenvelope for absorbing future emissions is aresidual function of past emissions. In effect,the ecological ‘space’ available for futureemissions is determined by past action.Turning from stocks to flows produces adifferent picture. One striking feature of thatpicture is that emissions are highly concentratedin a small group of countries (figure1.5). The United States is the largest emitter,accounting for around one-fifth of the total.Collectively, the top five—China, India,Japan, the Russian Federation and the UnitedStates —account for more than half; the topten for over 60 percent. While climate changeis a global problem, national and multilateralaction involving a relatively small group ofcountries or groupings—such as the G8, theEuropean Union (EU), China and India—would encompass a large share of the totalflow of emissions.Much has been made of the convergence inemissions between developed and developingFigure 1.5Share of globalCO 2 emissions, 2004 (%)1009080706050403020100OthersGlobal CO 2 emissions are highly concentratedItalyKorea, Rep. ofUnited KingdomCanadaGermanyJapanIndiaRussianFederationChinaUnited StatesSource: CDIAC 2007.AustraliaAustriaBelgiumCanadaCzech RepublicDenmarkFinlandFranceGermanyGreeceHungaryIcelandIrelandItalyJapanKorea, Rep. ofLuxembourgMexicoNetherlandsNew ZealandNorwayPolandPortugalSlovakiaSpainSwedenSwitzerlandTurkeyUnited KingdomUnited StatesOECDCanadaFranceGermanyItalyJapanRussianFederationUnited KingdomUnited StatesG8AustriaBelgiumBulgariaCyprusCzech RepublicDenmarkEstoniaFinlandFranceGermanyGreeceHungaryIrelandItalyLatviaLithuaniaLuxembourgMaltaNetherlandsPolandPortugalRomaniaSlovakiaSloveniaSpainSwedenUnited KingdomEUAfghanistanAngolaBangladeshBeninBhutanBurkina FasoBurundiCambodiaCape VerdeCentral AfricanRepublicChadComorosCongo, Dem.Rep. of theDjiboutiEquatorial GuineaEritreaEthiopiaGambiaGuineaGuinea-BissauHaitiKiribatiLao People'sDemocratic Rep.LesothoLiberiaMadagascarMalawiMaldivesMaliMauritaniaMozambiqueMyanmarNepalNigerRwandaSamoaSao Tome andPrincipeSenegalSierra LeoneSolomon IslandsSomaliaSudanTimor-LesteTogoTuvaluUgandaTanzania, UnitedRep. ofVanuatuYemenZambiaLDCs1The 21 st Century climate challengeHUMAN DEVELOPMENT REPORT 2007/2008 41