Climate change can disrupt ecological, social and economic systems, with some regions and sectors suffering significantly. Therefore, adaptation plays a paramount role in responding to climate change. Progress has been made, but there are still important obstacles. Knowledge of the benefits and costs of adaptation is sparse, unsystematic and unevenly distributed across sectors and countries. Planning suffers from substantial uncertainties in terms of precise impacts. It is also difficult to reconcile the bottom-up nature of adaptation with top-down strategic policy making on adaptation. To address these challenges BASE will:Improve adaptation knowledge availability, integration and utilizationCase studies will be used to understand facilitators of, and barriers to, adaptation. Over 20 cases have been selected to cover the diversity of adaptation, simultaneously paying attention to the need for generalization and comparability. The gap between top-down strategic assessments of costs and benefits and empirical context-sensitive bottom-up analyses will be bridged using novel combinations of models and qualitative analyses.Promote and strengthen stakeholder participation in adaptationBASE will support stakeholder involvement through novel participatory and co-design techniques. Successful bottom-up initiatives will be studied, and the use of knowledge, two-way learning, the role of social media and other awareness raising methods and tools will be explored.Support coherent, multi-level, multi-sector integrated adaptation policiesBASE will provide policy guidelines by integrating lessons from past experiences, case studies, insights provided by modeling and stakeholder participation. Issues of multilevel, cross sectoral and inter-temporal governance that are presently weakly tackled will be highlighted. Potential conflicts and synergies of adaptation with other important policies will be explored to overcome constraints caused by context-related inertias.