White paper: The last interglacial and beyond: A northwest Greenland deep ice core drilling project

Starting with the initial projects in the 1960s (Camp Century and Byrd), deep ice cores have come to be regarded as a crucial pillar of knowledge about late Quaternary palaeoclimate. The current state of the art is represented in Greenland by the three detailed records of GRIP and GISP2 (at Summit) and of NGRIP (NorthGRIP). These are supplemented by the earlier records from Dye 3 and Camp Century, and by the more compressed but valuable Greenland coastal cores (such as Renland). The most compelling message from the Greenland cores has been that of the very abrupt, millennial-scale, climatic flips of the last glacial period, known as Dansgaard-Oeschger events. Understanding the cause of these events, and their implications for future change, has become one of the hottest topics in climate studies, with significant policy implications.

Despite their great significance, the existing Greenland cores are deficient in one important respect. The last interglacial (also known as the Eemian) has proved to be a tantalising target: Eemian ice is present but highly garbled in the Summit cores, incomplete due to basal melting in the NGRIP core, and too compressed to use in the Camp Century and Dye 3 cores.