The Arctic Realm is changing rapidly and the fate of the cryosphere, including Arctic sea ice, glaciers and the Greenland Ice Cap, is a source of concern. Melting of ice not only impacts on the radiative energy budget and sea level, but it may also modify the oceanic circulation and the boreal ecosystem of the North Atlantic and further afield. Many of the processes and feedbacks operate on time scales too long for instrumental observations and the sensitivities and natural variations in key Earth System components in the Arctic, subarctic and North Atlantic regions can be studied from the geological archives. In this session, we invite contributions from a range of disciplines and across time scales, including observational data, proxy data, model simulations and forecasts in the past and future. The common denominator of these studies will be their focus on a better understanding of processes on short to long time scales in the Arctic-subarctic and North Atlantic and their impact on climate and environmental conditions, at regional to global scales.