Download all Technical Policy Briefing Notes in a single ... - Mediation

DecisionSupport 7uses numerical values (e.g. as in the scale below)to conduct the pairwise comparisons,constructing a set of pairwise comparisonmatrices. Several matrices are produced tocompare the alternatives (e.g. adaptationoptions) with respect to each criteria, and thecriteria with respect to the goal.4. Calculate relative priorities. This can be doneusing a spreadsheet, or software, such asExpertChoice. 1 The values in Step 3 areprocessed to obtain numerical priorities orweights for the criteria and alternatives.Depending on the problem at hand, a priority orweight can refer to importance, preference orlikelihood.5. Aggregate priorities. The final step is toaggregate relative priorities to produce overallpriorities (final evaluation metrics) which sum to1.0.The Application to AdaptationAHP has been used in a wide variety of fieldsincluding engineering, business strategicmanagement, education and quality assessment.The approach has high relevance for the analysisof climate adaptation related decisions, given itis useful where a range of stakeholders aredealing with issues that have a high degree ofcomplexity, that involve uncertainty and risk, andinclude subjectivity, i.e. human perceptions andjudgments. It is also potentially useful when theoutcomes have possible long-termconsequences (Bhushan, 2004).The tool has a particular relevance whereimportant elements of the decision are difficult toquantify or compare, or where different expertise,goals, and world-views are a barrier toconsensus-building and communication.In the context of climate adaptation, the methodcan be used to compare a set of adaptationoptions against a set of defined criteria usingparticipants’ experience and judgment about theissues of concern. It allows the comparison ofdiverse elements that are often difficult tomeasure in a structured and systematic wayusing a scale. This makes it particularly relevantfor sectors or key criteria where quantification ischallenging.The first applications of the approach to climatechange were in the context of the globalnegotiations on climate change (Ramanathan,1998) and later in mitigation policy instruments(Konidari and Mavrakis, 2007). AHP is nowincreasingly being applied in the area of climatechange adaptation. It was applied using aparticipatory approach for the integration ofindigenous knowledge within adaptationstrategies in the Tabasco Plains of Mexico(Ponce-Hernandez and Patel, forthcoming), inthe evaluation of adaptation options for humansettlements in South East Queensland (Choy etal., 2012), in the integration of GIS modelling tolook at crop impacts in Australia (Sposito, 2006)and to explore the impacts of storm surge andsea level rise in Canada and Caribbean (Laneand Watson, 2010). Yin et al (2008) applied AHPto evaluate adaptation options for the watersector in the Heihe River Basin in north-westernChina, resulting in a higher preference forinstitutional options for managing water demand(imposing constraints on large consumers, waterconservation initiatives through water userassociations, and transferrable water allocationpermits), rather than ‘hard’ engineering optionsfor increasing water supply.1http://expertchoice.com/2