Climate change impact assessment as function of model inaccuracy

P. Droogers (1) , A. van Loon (1) , W. Immerzeel (1)

1 Future Water

Numerical simulation models are frequently applied to assess the impact of climate change on hydrology and agriculture. A common hypothesis is that unavoidable model errors are reflected in the reference situation as well as in the climate change situation so that by comparing reference to scenario model errors will level out. For a polder in The Netherlands an innovative procedure has been introduced, referred to as the Model-Scenario-Ratio (MSR), to express model inaccuracy on climate change impact assessment. MSR values close to 1, indicating that impact assessment is mainly a function of the scenario itself rather than of the quality of the model, were found for most indicators evaluated. More extreme climate change scenarios and indicators based on threshold values showed lower MSR values, indicating that model accuracy is an important component of the climate change impact assessment. It was concluded that the MSR approach can be applied easily and will lead to more robust impact assessment analyses.

Domaines: Interfaces continentales, environnement; Océan, Atmosphère; Sciences de la Terre

P. Droogers, A. van Loon, W. Immerzeel. Climate change impact assessment as function of model inaccuracy. Hydrology and Earth System Sciences Discussions, 2007, 4 (5), pp.2875-2899. ⟨hal-00298877⟩