A framework for testing the ability of models to project climate change and its impacts
Refsgaard, Jens Christian × Madsen, H. Andréassian, V. Arnbjerg-Nielsen, K. Davidson, T.A. Drews, M. Hamilton, D. Jeppesen, E. Kjellström, E. Olesen, J.E. Sonnenborg, T.O. Trolle, D. Willems, Patrick Christensen, J.H. #
Climatic Change vol:122 issue:1-2 pages:271-282
Models used for climate change impact projections are typically not tested for simulation beyond current climate conditions. Since we have no data truly reflecting future conditions, a key challenge in this respect is to rigorously test models using proxies of future conditions. This paper presents a validation framework and guiding principles applicable across earth science disciplines for testing the capability of models to project future climate change and its impacts. Model test schemes comprising split-sample tests, differential splitsample tests and proxy site tests are discussed in relation to their application for projections by use of single models, ensemble modelling and space-time-substitution and in relation to use of different data from historical time series, paleo data and controlled experiments. We recommend that differential-split sample tests should be performed with best available proxy data in order to build further confidence in model projections.