Summary
The continental ice sheets of both polar regions form one of the most important natural archives for paleoclimatic as well as paleoatmospheric research. Ice cores provide unique high-resolution information not only on temperature and precipitation rate but also on atmospheric circulation and the composition of the atmosphere in the past. The long-term records of all these parameters complement each other and allow to draw a comprehensive picture of past changes in the climate system. The time scales which can be investigated on polar ice cores range from seasonal variations, anthropogenic trends during the late Holocene, rapid climate variations during the last ice age up to long-term climate variations connected to the last four glacial/interglacial cycles. In this review the fundamental glaciological, physical and biogeochemical background necessary for the interpretation of ice core proxy records is summarized and the most important results gained from ice core studies during the last decades are presented.