The SYNICE project seeks to improve the understanding of pan-Arctic and North Atlantic climate and human systems through the integration and syntheses of several sea-ice data sets together with information from the physical and social sciences. The project is analyzing data from the past 1000 years, with major emphasis on the period c. AD 1800 to the present. Five major locations/sea-ice data sets are being considered: i) The sea-ice record from Iceland; ii) The sea-ice record from the Barents Sea area; iii) The record of historical ice conditions around Newfoundland and on the Grand Banks, and in the Gulf of St. Lawrence and the Scotian Shelf; iv) The Odden region of the central Greenland Sea; v) A climate and sea-ice record based on Moravian missionary accounts from Nain, Labrador. Two other components will investigate local knowledge of sea-ice and other climate changes, specifically in Iceland and Labrador/Nunatsiavut. Deliverables include: i) Development of a new 150-year central Greenland Sea ice-atmosphere dataset; ii) Analysis and modeling of the relationship between ice extent and production in the Central Greenland Sea and the occurrence of deep convection; iii) An interpretation of how Greenland Sea convection has varied over the past 150 years, together with implications of this for the development of ocean changes and marine climate in the Nordic Seas during this period; iv) A homogeneous and reliable long-term sea-ice record for Iceland; v) A synthesis of the sea-ice records with circulation data in order to gain insights into past, present and future natural climate variability of pan-Arctic systems; and vi) a study of the social impacts of changing Arctic and Subarctic environments.