The 21st Century climate challenge

Box 3.3The United Kingdom's climate change bill—setting a carbon budgetThe United Kingdom’s Climate Change Bill is a bold and innovativeproposal to create a national carbon budget that supportsglobal mitigation efforts. Legislation would commit Governmentto mandatory cuts in emissions over time. Applied more widelyacross the developed world, the broad approach could underpin astrengthened post-2012 Kyoto system. However, there are seriousquestions about the level of ambition—and about the UnitedKingdom’s capacity to meet its own carbon reduction targets.The Climate Change Bill charts a pathway for emissionsreductions to 2050. An expressed aim is to contribute to internationalefforts to avoid dangerous climate change, which the UnitedKingdom Government identifi es as a global mean temperatureincrease in excess of 2°C. The roadmap sets the 2050 target forgreenhouse gas emissions reductions at 60 percent, with an interimtarget of 26–32 percent reductions by 2020 against levels in 1990.These targets would be fixed in a system of ‘carbon budgets’—rolling 5-year limits on CO 2emissions. Three budgets would be setin advance, helping to create a long-term horizon for business andinvestment decisions. Legislation would create enabling powersthat make future policies for controlling emissions quicker andeasier to introduce. However, two issues will have to be addressedif the Climate Bill is to provide the framework for a sustainablecarbon budget.The first problem is one of overall ambition. Emission targetsin the Climate Bill are not consistent with the objective of avoidingdangerous climate change. Our sustainable emissions pathwaysuggests that developed countries need to cut emissions ofgreenhouse gases by at least 80 percent by 2050 against 1990levels, not 60 percent. Moreover, the current framework excludesaviation and shipping. Factoring them in would raise the cumulativeUnited Kingdom carbon budget to 2050 by around 5.5 Gt CO 2, or27 percent.If the rest of the developed world followed the pathway envisagedin the United Kingdom’s Climate Change Bill, dangerousclimate change would be inevitable. It would lead to approximateatmospheric concentrations of greenhouse gases in excess of660 ppm CO 2e, and possibly 750 ppm CO 2e. These are outcomesthat would correspond to a rise in average global temperatures of4–5°C, well beyond the dangerous climate change threshold. Theoverarching requirement for keeping within the 2°C threshold is astabilization of greenhouse gas stocks at 450 ppm CO 2e.The second problem to be addressed is the direction of currentgreenhouse gas emissions (see figure). On a positive note, theUnited Kingdom is one of a small group of European Union countriesthat is on-track for achieving its Kyoto Protocol target. Whilethe economy has expanded by 47 percent since the 1990 base yearfor Kyoto, emissions of CO 2are 5 percent lower. The less positivenews is that all the reduction took place prior to 1995. Since 2000,emission levels have increased by 9 Mt CO 2(to 567 Mt CO 2in 2006).The upshot is that the national target of reducing CO 2emissions to20 percent below 1990 levels by 2010 is now unattainable: the likelyoutcome is a reduction less than one-half this target.CO 2trends are off track for national targetUnited Kingdom CO 2emissions (Mt CO 2)600TotalDomestic5002010 targetTransport400300Power stations200100Other01990 1994 1998 2002 2006Source: Government of United Kingdom 2007c.Breaking down emission sources for CO 2by sector helps toidentify some of the challenges facing the United Kingdom. Emissionsfrom power stations, which represent around one-third of thetotal, have increased in five of the last seven years. The transportsector, now the second largest source of emissions, is on a sharplyrising trajectory, while emissions from industry and the residentialsector have not moved significantly. Changing these CO 2emissiontrajectories to make possible a reduction of 26–32 percent by 2020will require radical new policies that align energy policy with climatechange mitigation goals. Among the options:• Carbon taxation and strengthened cap-and-trade. Carbonpricing is critical to sustainable carbon budgeting. Signallinga commitment to carbon taxation in the range outlined in thischapter offers one route for aligning energy markets with sustainablecarbon budget goals. Working through the EuropeanUnion’s cap-and-trade scheme is another option (section 3.2),provided that the ceiling on emissions is set at a level consistentwith 26–32 percent cut in emissions by 2020.• Power generation. The future energy mix in power generation willshape the United Kingdom’s emissions trajectory. Since early2000, increased use of coal, the most polluting fossil fuel, hasbeen instrumental in driving up emissions. Regulatory mechanismscould be deployed to initiate the rapid retirement of highlypolluting plants, with a commitment to the accelerated introductionof zero-emission coal plants. Britain also lags far behindbest European Union practice on renewable energy: it currentlyproduces only 2 percent of its overall energy from renewables.3Avoiding dangerous climate change: strategies for mitigationHUMAN DEVELOPMENT REPORT 2007/2008 121