these include marginal abatement cost curve analysis options analysis impact assessments costbenefit analysis and multicriteria analysis however information and data constraints can limit their application in particular limited evidence and knowledge to provide good appraisals and identify market failures and barriers as well as inherent uncertainties in appraising climate adaptation projects are cited as key barriers to identifying effective projects exante such methodologies can help to direct allocation of future climate finance to projects and programmes with the highest overall results for example the uk s dfiddecc greenhouse gas appraisal guidance and the world bank source book