This paper summarizes typical energy-balance data for a variety of polar terrain types, to aid in a better understanding of climate and climate change. Terrain types examined include closed boreal forests, open woodlands, tundra, the pack ice of the Arctic Ocean, glaciers and large ice sheets. For each of these terrains energy-balance-related parameters, including albedo, surface roughness, and thermal diffusivity of the subsurface and their seasonal variations are considered. Components of the surface energy balance, and particularly the net radiation or radiation balance, are presented on a seasonal basis. Net radiation is shown to be a poor indicator of climate, if used as the sole parameter, contradicting earlier conclusions by some climatologists. Large differences are shown between the energy balances of the various terrains in summer, with the boreal forest and the tundra acting as major heat sources for the surrounding terrains, and the glaciers acting as major heat sinks. In winter, thin pack ice is the major source of heat energy. These factors not only affect the regional climates of the Arctic, but influence global climate through feedback processes.