This study is intended to analyze climate change adaptation measures by applying the techniques that are proposed in the decision-making theory and economic theory with considering the uncertainty of climate change. Climate change is related deeply with uncertainties of various kinds of issues, such as in weather and ecosystem and economic system. The exact interpretation and evaluation of those uncertainties in policy analysis is very important.
Regarding climate change, there is a need for measures from both sides of the adaptation measures and mitigation measures.For long years, the main discussion point of climate change policy was on mitigation measures, but, it is becoming attention gathered in recent years adaptation measures. Although there is growing need for evaluation methods of the international climate change adaptation measures, and the discussion in OECD have been made, still definitive evaluation method does not exist. In this study, we take advantage of the latest knowledge of the methodology related to decision analysis under uncertainty, and make a study of the evaluation methods which can be applied to climate change adaptation measures in the evaluation of future JICA projects. The study, firstly discusses evaluation methods related to climate change adaptation measures in consideration of the uncertainty. And apply to case study "Kenya Mwea Irrigation Development Project (ODA loan projects)". Further draw also general and academic knowledge on climate change policy by combining the information obtained through case studies and a number of economic modeling techniques.