In the international arena, two broad policy responses have emerged to deal with negative impact of climate change, i.e. 'mitigation' and 'adaptation'. Though adaptation is required to reduce unmitigated climatic impact, the ongoing international climate conventions and scholarly studies have given less emphasis to it in comparison to mitigation. In climate change economics literature, the notion adaptation has been used in two discourses: 'impact' and 'vulnerability', and both are different in the context of not only addressing research question but also assessing adaptive capacity. Assuming adaptation as 'static or end-point' approach, the impact studies have estimated potential impact cost, which involves both adaptation and residual or un-mitigated impact cost, based on projected emission scenarios now and forever. The vulnerability studies, in contrast, have presumed adaptation as 'starting-point' approach, and assessed risk of an entity within the broader social, economic, political and environmental context. In the context of adaptation, the former (impact) assumes clairvoyant farmer hypothesis, and hence, suggests climate specific adaptations. The later (vulnerability), on the other hand, views adaptation as the current ability of a person to cope with risk and secure livelihoods, which in particular assessing vulnerability, who adapts and his/her risk attitude behaviour, and process of occurring adaptations. Though the purpose of both is to reduce negative impact through adaptation, the present study surveys both the sets of studies based on two questions: how the notion of adaptation is being articulated and to what extent their findings are useful for implementing and facilitating adaptations
