To what extent does bias correction and downscaling increase the value of GCM outputs for regional-scale applications?This chapter provides an overview of the concept of added value for downscaling studies and discusses the methods and metrics used for evaluating the value that bias correction and downscaling, using an RCM and/or an ESDM, adds to climate projections for impact assessments

What lies in the future of regional downscaling, and how will future developments advance the information available for impacts and policymaking analyses? Models and methods are constantly under development; what might users expect to become available over the next decades as computing resources reach and extend beyond exascale (over 100 times faster than the current fastest computers), and global climate model resolutions reach regional scales? What uncertainties will remain to be resolved, even with these advances? By its nature, much of this discussion is somewhat philosophical and this chapter does not include real-world case studies. Instead, it highlights specific ways assessments may be affected by future advances and discusses key areas of future development.