The Cenozoic Arctic sea-ice cover owes its existence to the geographical polar position of the Arctic Ocean, its oceanographic isolation and its small solar seasonal insolation (at least during the winter) and hence cool to cold temperatures, as well as its interaction with the continental hinterlands. The major point of this paper will address the impact of paleophysiographic changes of the northern hemisphere (mainly in Siberia) on the history of its ice covers. The vagueries of the Cenozoic Arctic ice-cover history require intensified future studies, but have the potential of contributing to our understanding of future environments on the Northern Hemisphere. This may have its implications for the socioeconomic conditions for the societies inhabiting high northern latitude land areas, probably beyond that even on a global scale. Climatic conditions during the young geologic past were sometimes warmer than today; the climate has a "memory", and as such reconstructed conditions might offer analogues for what is in store for the future for all of us.