Are the UKCIP02 scaling factors still correct and how does one produce scaling factors with UKCP09?

UKCP09 represents a more up-to-date set of projections. Changes to the modelling methodology used for UKCP09 mean that simple scaling factors are no longer used.

In detail

For UKCIP02, computational limitations meant that model results were limited to a single emissions scenario (SRES A2; UKCIP02 Medium-High) and a single future time-period (2071–2100, the 2080s). Climate change projections for other emissions scenarios and time periods were estimated based on a standard set of scaling factors for the UK, derived from the results of one climate model, HadCM3.

In UKCP09, a different approach has been adopted. Individual model runs have been carried out for the three emissions scenarios (Low, Medium and High) and for the whole period 1961–2099, rather than scaling from a single emission scenario and time period. Both of these advances mean that there is no standard set of scaling factors for UKCP09.