Are the other climate models that are incorporated in the UKCP09 probabilistic climate projections weighted?

No, the alternative global climate models are not weighted in UKCP09 and are considered equally valid.

In detail

The UKCP09 modelling and statistical framework involves incorporation of single model results from other global climate models. In principle, each of these models could be weighted, but in practice there is no recognised robust method of assigning them relative weights. In UKCP09, all of the other global models used are therefore assumed to be equally valid.

Find out more

• IPCC AR4