The worldwide public is aware that humankind lives in a changing environment. Typical questions to scientists addressed by the public are e.g.: How much will sea level rise at our shores in 100 years? How will average seasons and the distribution of precipitation be in 30 years in our country? Will we be able to send ships over the North Pole in a few decades?To address these questions one has to understand the various interactions between the atmosphere, the oceans and the ice covering both polar land and seas. The changing physical properties are tightly coupled to the biological and geochemical cycles which have therefore to be included to forecast the fate of the earth system. Ice is a key player in the earth system as the polar ice sheets store an equivalent of more than 60 m of sea level difference. Sea ice has compared to open water a much higher ability to reflect radiation instead of heating by absorption.Both the Alfred Wegener Institute (AWI) and the Institute of Low Temperature Science (ILTS) have some of their major research topics covering aspects of ice beginning with the basic physical properties of ice crystals and their inclusions, formation of meteoric and sea ice, internal structure of ice sheets towards modelling and observing the evolution of ice sheets and sea ice in the earth system. Together both institutes cover an almost complete portfolio of research addressed to ice and lay the basis for research towards answering the questions by the public.Selected ice research topics relevant for the AWI and the ILTS will be presented, as e.g. microstructure of ice, internal electromagnetic reflections in ice sheets, air content in natural ice, modelling the evolution of ice sheets and distribution of sea ice under different climatic conditions. Latest reconstructions of sea ice extent and ice sheet geometry from proxy parameters in ice and sediment cores permit the comparison with modelling results.