Workshop on Seasonal to Multi-Decadal Predictability of Polar Climate; Bergen, Norway, 25–29 October 2010; Over the past few decades the two Earth poles have exhibited drastically different behavior. The Arctic has warmed, as expected from the polar amplification of global warming, although the observed rate of summertime sea ice retreat is at the upper limit of climate model predictions. At the same time, Antarctic sea ice extent is increasing, contrary to model predictions. However, natural variability in polar regions is large, with substantial power at multidecadal time scales. All this leads to considerable uncertainty concerning the future evolution of polar climate over the next few decades. To address this issue, the World Climate Research Programme (WCRP) convened a workshop to assess scientists' current knowledge of the predictability of polar climate and identify physical mechanisms that could be exploited to improve predictive capability. The workshop participants included experts in observations, theory, processes, and modeling, and they looked at both polar regions in the context of their coupling with the global climate system.