The Earth System Model Evaluation Tool (ESMValTool) is a community diagnostics and performance metrics tool for the evaluation of Earth System Models (ESMs) that allows for routine comparison of single or multiple models, either against predecessor versions or against observations. Specific scientific themes include, for instance, selected Essential Climate Variables (ECVs), a range of known systematic biases common to ESMs, such as coupled tropical climate variability, monsoons, Southern Ocean processes, continental dry biases and soil hydrology-climate interactions, surface water and energy fluxes as well as atmospheric CO2 budgets, tropospheric and stratospheric ozone, and tropospheric aerosols. The tool is being developed in such a way that additional analyses can easily be added. A set of standard namelists for each scientific topic reproduces specific sets of diagnostics or performance metrics that have demonstrated their importance in ESM evaluation in the peer-reviewed literature. The ESMValTool is a community effort open to both users and developers encouraging open exchange of diagnostic source code and evaluation results. This will facilitate and improve ESM evaluation beyond the state-of-the-art and aims at supporting such activities within the Coupled Model Intercomparison Project (CMIP), the European Commission’s Horizon 2020 Project CRESCENDO and at individual modeling centers.

The main reference paper for the ESMValTool is:

Eyring, V., Righi, M., Lauer, A., Evaldsson, M., Wenzel, S., Jones, C., Anav, A., Andrews, O., Cionni, I., Davin, E. L., Deser, C., Ehbrecht, C., Friedlingstein, P., Gleckler, P., Gottschaldt, K.-D., Hagemann, S., Juckes, M., Kindermann, S., Krasting, J., Kunert, D., Levine, R., Loew, A., Mäkelä, J., Martin, G., Mason, E., Phillips, A. S., Read, S., Rio, C., Roehrig, R., Senftleben, D., Sterl, A., van Ulft, L. H., Walton, J., Wang, S., and Williams, K. D.: ESMValTool (v1.0) – a community diagnostic and performance metrics tool for routine evaluation of Earth system models in CMIP, Geosci. Model Dev., 9, 1747-1802, doi: 10.5194/gmd-9-1747-2016, 2016.

The ESMValTool (for users) and the full User’s and Developer’s Guide are available from the ESMValTool website

The Quick Start Guide ESMValTool for CRESCENDO members is available to download through our Intranet. Alternatively, contact the ESMValTool core development team members for any further information and help.

ESMValTool main contacts

  • Veronika Eyring
    RT3 leader, ESMValTool PI
    Institute for Atmospheric Physics (DLR), Germany.
    Veronika Eyring
    RT3 leader, ESMValTool PI

    Veronika is involved in the World Climate Research Programme (WCRP) through her roles as Chair of the Coupled Model Intercomparison Project (CMIP) Panel and member of the scientific steering committees for the Chemistry-Climate Model Initiative (CCMI), the Working Group on Coupled Modeling (WGCM), the WCRP Data Advisory Council's (WDAC) Observations for Model Evaluation Task Team, and the Working Group on Numerical Experimentation (WGNE)/WGCM Climate Model Metrics Panel.

  • Alexander Löw
    WP7 leader, ESMValTool developer
    Ludwig Maximilian University (LMU), Germany
    Alexander Löw
    WP7 leader, ESMValTool developer

    Alex’s research interests involve: global energy and water flows, climate modelling and model evaluation, remote sensing (focusing microwave remote sensing), synergy of models and data (data assimilation).


  • Axel Lauer
    ESMValTool core developer
    Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Germany
    Axel Lauer
    ESMValTool core developer
  • Björn Brötz
    ESMValTool core developer
    Institute for Atmospheric Physics (DLR), Germany
    Björn Brötz
    ESMValTool core developer