Earth's energy imbalance since 1960 in observations and CMIP5 models.

Unlabelled: Observational analyses of running 5 year ocean heat content trends () and net downward top of atmosphere radiation () are significantly correlated ( ∼ 0.6) from 1960 to 1999, but a spike in in the early 2000s is likely spurious since it is inconsistent with estimates of from both satellite observations and climate model simulations. Variations in between 1960 and 2000 were dominated by volcanic eruptions and are well simulated by the ensemble mean of coupled models from the Fifth Coupled Model Intercomparison Project (CMIP5).

Do seasonal-to-decadal climate predictions underestimate the predictability of the real world?

Seasonal-to-decadal predictions are inevitably uncertain, depending on the size of the predictable signal relative to unpredictable chaos. Uncertainties can be accounted for using ensemble techniques, permitting quantitative probabilistic forecasts. In a perfect system, each ensemble member would represent a potential realization of the true evolution of the climate system, and the predictable components in models and reality would be equal.

Forecast cooling of the Atlantic subpolar gyre and associated impacts.

Decadal variability in the North Atlantic and its subpolar gyre (SPG) has been shown to be predictable in climate models initialized with the concurrent ocean state. Numerous impacts over ocean and land have also been identified. Here we use three versions of the Met Office Decadal Prediction System to provide a multimodel ensemble forecast of the SPG and related impacts.