A climate model projection weighting scheme accounting for performance and interdependence

Abstract Uncertainties of climate projections are routinely assessed by considering simulations from different models. Observations are used to evaluate models, yet there is a debate about whether and how to explicitly weight model projections by agreement with observations. Here we present a straightforward weighting scheme that accounts both for the large differences in model performance and for model interdependencies, and we test reliability in a perfect model setup. We provide weighted multimodel projections of Arctic sea ice and temperature as a case study to demonstrate that, for some questions at least, it is meaningless to treat all models equally. The constrained ensemble shows reduced spread and a…

• NS
  National Science Foundation
• UD
  U.S. Department of Energy

  Awards: DE-FC02-97ER62402, FC02-97ER62402
• NC
  National Center for Atmospheric Research
• EC
  European Commission

  Award: 641816
• OO
  Office of Science

  Awards: Cooperative Agreement DE-FC02-97ER62402, DE-FC02-97ER62402