The new Community Climate System Model version 3 (CCSM3) is being used for the next IPCC assessment. The A2, A1B, B1, and 20th century fixed concentration scenarios have been completed with an ensemble size of five. As expected, there are significant simulated future changes in the polar climate system. We will discuss in particular changes of snow cover, sea ice areal extent, and thickness as well as temperature, precipitation, and cloudiness. We will also examine the sensitivity to the different scenarios.