This seminar is based on a paper co-authored by Carlo Carraro ed Enrica De Cian. Today it is commonly accepted that a successful climate strategy should compound mitigation and  adaptation, but this recognition is quite recent. Presently, quantitative information is still largely insufficient to answer a set of key policy questions: what is the potential of adaptation to reducing climate-change damages? How much will it cost? When – where and what adaptation strategies should be adopted? How can adaptation actions be harmonised between them and with mitigation? More importantly, the literature provides very few examples where these questions are addressed in a single consistent analytical framework. The present work tackles all these aspects using a climate-economic hard-linked intertemporal dynamic optimization model, WITCH, enriched with an adaptation module parameterized according to the latest available knowledge. In our setting adaptation can take three different forms: building up of defensive capital (anticipatory adaptation), recovering interventions (reactive adaptation) and investment in a specific adaptation technology. Within the framework of the WITCH model these options are contrasted against each other and with alternative investment in energy production technologies to determining the optimal mix between adaptation, decarbonization of the economic system, and residual climate-change damage