Compared to uninitialized climate change projections, a multi-model ensemble from the CMIP5
10 year decadal prediction experiments produces more warming during the mid-1970s climate shift and less
warming in the early 2000s hiatus in both the tropical Indo-Pacific region and globally averaged surface air
temperature (TAS) in closer agreement with observations. Assuming bias in TAS has stabilized in the 10 year
predictions, after bias adjustment, TAS anomalies for the 2016–2035 period in the 30 year predictions initialized
in 2006 are about 16% less than the uninitialized projections. One contributing factor for the improved climate
simulation is the bias adjustment, which corrects the models’ systematic errors and higher-than-observed
decadal warming trend. Another important factor is the initialization with observations which constrains the
ocean such that the starting points of the initialized simulations are close to the observed initial states.