The full programme book (PDF) - Royal Geographical Society

modeling context, or in the context of comparing time sequences from models and
observations. It is clear that straightforward curve-matching approaches are not sufficient.
As an example, differences between members of an identically-forced ensemble of LM
climate simulations can result in offsets of more than 50 years and more than 5ppm in
simulated carbon fluxes. The differences in peak magnitudes of the CO2 flux are similar to
the differences caused by uncertainties in forcing during this interval.
Discrepancies between observations and model predictions are frequently ascribed to
failure to include all components of the climate system (e.g. MH vegetation, LGM dust).
The ongoing development of ESMs, which do incorporate this complexity, will address
such arguments but poses a major problem for model evaluation. Sub-models which
perform reasonably well in offline mode do not necessarily perform equally well when
included in the ESM framework; effects that are important in sensitivity tests have only
small impacts in the coupled model. Finding ways of evaluating the performance of each
sub-model is conceptually challenging and will certainly require a wider suite of
observations than currently available.