Adapting to Climate Change: Assessing the World Bank Group ...

CHAPTER 4ANTICIPATORY ADAPTATIONTable 4.3. Scenario and Adaptation Option Methods Used by Surveyed World Bank StudiesScenariomethodNotdoneLow-regret(robust)Options analysisAdaptivelymanagedPrecautionaryprincipleQualitative 1 2 0 0 0CostbenefitSensitivity test 2 0 ½ 1 2½Scenario-led 5 10½ ½ 1 2Scenarios:Qualitative: Refers to primary sources (such as IPCC) and/or applies simple climate narratives (such as hotter, warmer, drier, orearlier).Sensitivity test: Application of arbitrary climatic (and non-climatic) change factors to the inputs driving model(s) of the system(s)of interestScenario-led: Applies top-down approach to quantify outcomes arising from combinations of emissions, climate model,downscaling, and impact model uncertaintyOptions analysis:Low-regret (robust): Largely qualitative appraisal of scenario-neutral measures that should realize benefits under present climatevariability as well as future climate changeAdaptively managed: Flexible operations, forecasting, or innovative use of existing infrastructure to meet emergent climatetrends and/or changes in variabilityPrecautionary principle: Apply a safety margin for managing risk and uncertaintyCost-benefit: Monetization of adaptation options under climatic and non-climatic scenarios. Includes robust decision making withemphasis on “satisficing” rather than determining optimal solutions.Source: IEG (Half values are used for four projects that each use two methods of adaptation option analysis.)4.15 The review found that climate model information has generally been unable toinform quantitative decision making in the surveyed studies. Most studies adopted atraditional scenario-led approach to making climate projections. But over half of thestudies then recommended low-regret adaptation options that do not depend onclimate projections, and roughly one-quarter did not recommend adaptation options. Insome cases, climate projections were used to outline potential climate futures to informsensitivity-testing of project viability (Trung Son hydro, Kolkata flooding). Only in ahandful of cases were numerical predictions used as in input into design (Padmabridge, Kiribati high-tide calculator).4.16 In retrospect, the Bank Group has pioneered—often in innovative ways—the useof climate models, but has discovered that they often have relatively low value-addedfor many of the applications described in Table 4.2. An alternative approach wouldemphasize robust decision-making methods, where the analytic emphasis is onunderstanding how different investment options are sensitive to a range of possibleclimate outcomes, rather than on attempting to predict the future climate (Box 4-1). Itwould emphasize adaptive management, where policies and investment programs areupdated over time as future uncertainties are realized. And it would ensure that69