LAUSR

A surface cooling pattern in the equatorial Pacific associated with a negative phase of the Interdecadal Pacific Oscillation is the leading hypothesis to explain the smaller rate of global warming during 1998-2014, with these cooler than normal conditions thought to have accelerated the oceanic heat uptake. Here, using a 30-member ensemble simulation of a global Earth system model, we show that in 10% of all simulated decades with a global cooling trend, the eastern equatorial Pacific actually warms. Our finding challenges the view of the equatorial Pacific being the sole pacemaker for generating internal stochastic variability-driven global warming hiatus decades and suggests that past and future surface temperature patterns during hiatus decades may be distinct. In addition, the global ocean heat uptake tends to slow down during hiatus decades implying a fundamentally different global climate feedback factor on decadal timescales than on centennial timescales and calling for caution inferring climate sensitivity from decadal-scale variability.